Insulating interior walls is a crucial aspect of home insulation, providing maximum comfort and energy efficiency. Spray foam insulation is an excellent choice for this purpose due to its excellent sound deadening properties. Interior walls are primarily insulated for sound absorption, and the method of insulatement depends on the remodeling work being done. Injecting spray foam insulation into existing walls is one of the best ways to achieve this, as it can be applied directly to the interior of concrete foundation walls and under basement floor slabs.
Injection foam is similar to individual cans of foam insulation found in home centers but on a much larger and more extensive surface. If there is no insulation in your walls, adding spray foam is a fairly easy process, requiring you to drill a few easily patched holes in your walls. The best R-value for insulation and the thinnest insulation with the highest R-value are important factors to consider when installing spray foam insulation.
Spray foam insulation can be installed directly to the interior of concrete foundation walls and under basement floor slabs, but high density closed cell or low density open cell spray foam should not be used on these areas. Spray foam insulation can be installed both closed-cell and open-cell, making it one of the easiest insulation materials to install in a home that already has existing walls.
However, it is not recommended to install spray foam insulation yourself, as it cannot be installed without disturbing the existing walls. To insulate existing walls, drill holes into the studs of the wall and apply spray foam to fill the walls. Applying foam insulation to existing walls creates an air seal that can help address cold spots and drafts. RetroFoam of Michigan offers a variety of foam insulation options to suit different needs and preferences.
📹 Everything You Need to Know About Spray Foam
Today we’re going to be myth-busting and experimenting with all different kinds of spray foam, so that you understand the …
Where should you not use spray foam?
Spray foam insulation should not be applied directly to unvented crawl spaces or attics without proper moisture control measures in place. Without such measures, it can trap moisture, leading to mold growth, rot, or structural damage. It is also not recommended to apply spray foam insulation to HVAC equipment or combustion appliances, as the chemicals in the insulation can be flammable and pose a fire hazard if exposed to high temperatures.
Exterior applications of spray foam insulation require proper protection against sunlight, moisture, and physical damage. UV exposure can cause degradation of the insulation, reducing performance and appearance. Additionally, if the insulation is not adequately protected from moisture, it can absorb water, compromising its effectiveness. Proper exterior cladding or coatings are essential to shield spray foam insulation in these applications.
Where not to use expanding foam for walls?
Expansive foam should not be used near lightboxes, ceiling lights, or heating appliances as it can catch fire due to its flammable nature. It may also cause damage to the light itself if it cures around wiring. Some foams may claim to be usable in close contact with ceiling lights, but it is recommended to consult a professional for guidance.
Pre-existing conditions should not be used with expanding foam without a mask, as it contains isocyanates, a chemical that can cause serious breathing and skin-related issues. To avoid these risks, use breathable masks and protective eyewear. If you are at risk of serious side effects, find an alternative method of filling cavities.
When purchasing foam, choose the correct type, such as open and closed cell or high expansion and low expansion, as they behave differently. Open-cell foam is more effective and expands quicker than closed-cell foam, making it an alternative to installing new insulation.
Where not to use expanding foam?
Expansive foam should not be used near lightboxes, ceiling lights, or heating appliances as it can catch fire due to its flammable nature. It may also cause damage to the light itself if it cures around wiring. Some foams may claim to be usable in close contact with ceiling lights, but it is recommended to consult a professional for guidance.
Pre-existing conditions should not be used with expanding foam without a mask, as it contains isocyanates, a chemical that can cause serious breathing and skin-related issues. To avoid these risks, use breathable masks and protective eyewear. If you are at risk of serious side effects, find an alternative method of filling cavities.
When purchasing foam, choose the correct type, such as open and closed cell or high expansion and low expansion, as they behave differently. Open-cell foam is more effective and expands quicker than closed-cell foam, making it an alternative to installing new insulation.
Is foam insulation in walls a good idea?
The BS* + Beer show discusses spray foam insulation, its properties, application strategies, and potential environmental issues. Spray foam is a popular choice for high-performance home builders due to its thermal insulation and air barrier properties. However, it comes with environmental costs. The hosts discuss issues like blowing agents, offgassing, fire risks, R-value over time, ventilation requirements, two-component kits, and the issue of “when spray goes wrong”. The next show is scheduled for April 6, 2023.
What is the cheapest way to insulate internal walls?
Insulation boards are a popular and affordable method for insulateng internal walls, as they are easy to install and relatively inexpensive. Battening the walls and building a stud wall are other affordable ways to insulate walls, but they come with their own costs and benefits. Battening the walls can help reduce heat loss and improve air quality, while building a stud wall can increase insulation’s durability and reduce the need for costly insulation materials. By implementing these methods, homeowners can make their home more energy-efficient and comfortable.
Does spray foam create moisture problems?
Properly installing spray foam insulation is crucial for your woodstock home to prevent moisture issues. This insulation is effective but requires a proper air seal for temperature and moisture control. It’s essential to have a professional install spray foam insulation, as some products contain isocyanates that can cause health problems for installers. Primary dangers include asthma, breathing difficulties, coughing, throat irritation, chest pain, fever, and extreme sickness.
Is there a downside to spray foam insulation?
Spray foam insulation is a popular and affordable product due to its quick installation process and low cost. However, it can contract over time, reducing its insulation capabilities. This issue is more common in areas with high temperature variations. To fix this, more foam is needed or a new application is installed. Proper installation requires expertise, as the product dries rapidly during the installation process, especially for open-cell versions.
The cloth folds over on itself, leaving empty sections hidden from view. Unprofessional installers may overlook entire areas. Hiring a skilled contractor like Epic Spray Foam is recommended. Future issues may arise if the product is too thick or too thin, which can be problematic for homeowners.
Can mold grow behind spray foam insulation?
Spraying foam insulation over mold does not solve the problem. Premium foam insulation does not sustain mold growth, as it lacks a food source for mold to grow on. While it can help stunt growth and prevent spread, it doesn’t necessarily solve the problem. It’s recommended to address the mold problem before applying foam insulation, whether in crawl spaces, basements, or attics. It’s crucial to solve the root cause of mold in your home, as it can lead to dangerous health issues for family members.
What is the best way to insulate interior walls?
Loose-fill insulation is the best option for adding insulation to existing interior walls, as it can be blown into a small hole cut into drywall, minimizing the project’s work and mess. The most affordable option is rigid form board, which requires completely opening the wall, increasing the project’s cost and timeline. However, it may be a good option for building a new interior wall to divide an existing space.
Prioritizing your next project should focus on improving HVAC efficiency or improving exterior wall insulation, as these solutions typically offer immediate and long-term energy efficiency improvements.
Can you foam insulate interior walls?
Spray foam insulation can be installed in existing walls, both closed-cell and open-cell. However, it cannot be installed in existing walls with fiberglass insulation. To insulate an existing wall with fiberglass insulation, you must remove all the fiberglass. To install spray foam insulation, create small holes around one inch in diameter and inject the liquid spray foam directly into the wall cavity.
The spray foam will slowly expand and fill every nook and cranny in the existing wall, hardening into a highly effective and durable insulation material. This method is easy to install in existing homes.
How long do you have to stay out of the house after spray foam insulation?
After spray foam installation, it is safe to return home after curing, as all off-gassing fumes have dissipated or been ventilated out of the home. The curing process takes approximately 24 hours, and it is safe to return home as early as a day after the installation. Evacuating your home during spray foam installation is not due to safety concerns but because the manufacturing process creates a hazardous byproduct. The process can be frustrating and inconvenient, but it is essential to ensure a safe and comfortable return home.
📹 Can You Add Spray Foam Insulation to Existing Walls? | Foam University
When looking to improve your home’s insulation, can you add spray foam insulation to existing walls? Learn more about this …
I have come to realize that Jeff is a straight shooter. When I need to perform a particular task, even if I think I know how to proceed, I always look to see what he would do. I haven’t found a task yet that he doesn’t make it easier or safer for me to accomplish. He has also renewed my DIY interests since I’m now retired. Thanks, Jeff, keep up the good work.
I have definitely noticed that the window/door stuff doesn’t push and bow things out, and the regular gap filler one does. Window/door is also much softer and flexible once cured, while the regular stuff is quite hard. The formulas can’ be the same, although I do agree their expansion really does look the same.
Ten years ago when I was rehabbing my 100-yr-old, dilapidated house, the foam expanded about 10x the volume that was sprayed. In order to use up a can on the same day it was opened, it was put everywhere around the foundation — I’m still chiseling the stuff back! (It turned into orange foam rocks.) Im very appreciative of your comparison, Jeff, because I would’ve been working under old information with the can of pest block I picked up.
You’re absolutely right, it’s the same here in EU. There used to be foam that bubbled up with a lot of force, foam that bubbled up without pushing things out of square, foam that barely expanded, foam that stuck like crazy… Now it’s pretty much all the same low expansion stuff you have to empty a whole can around a single door that sticks to everything but the mounting side of the door frame. I believe it has to do with fire and insulation regulations, but like you say, if fire gets to the foam in most cases you’d better be long out of there anyways, and sometimes you just want to fill a gap to keep the noise and draft away without having the intention to build an ultra-insulated sealed zero-energy home.
So this is my take on the differences between the foams. The regular foam partially hardens before it finishes expanding. This causes it to build pressure and cause doors and windows to jam. On the other hand, the windows and doors formula will fully expand before it hardens and this prevents it from building pressure and instead just oozes out. I haven’t noticed any difference between the big gap and the regular foam.
A realistic test would be to spray the foam between two boards. You’ll see the difference, not only in color, but in the density of the foam. You’ll notice the difference by poking it with a screwdriver after it hardens. Heavier foams exert more pressure and expand less. Using heavy foam where light foam can cause warping, cracks and other damage.
Great article. Story: My ex and I remodeled a home. She used some of this foam to fill gaps. It really expanded and she used her bare hands to smooth the foam instead of waiting until it dries and cut it off. She came into the kitchen to wash her hands which were both covered in foam. I told her to stop. DO NOT GET YOUR HANDS WET!!!! It will set the foam. I asked her if she had any fingernail polish remover. Nope. I then told her to just chill out and I drove to Home Depot to get some acetone to clean her hands. When I got out of my truck when I got home, I could hear the water running. I rushed into the kitchen and she was madly washing her hands. The acetone did NOT remove the hardened foam. It took about 10 days for all of the foam to come off with lots of picking and rubbing. It was heartbreaking that she did not believe me and washed her hands anyway.
This was actually a very helpful article. I knew NOTHING about Home Improvement a few years ago. I started working at The Home Depot and I’ve been slowly learning. My family and I moved into a house from an Apt late 2020. I’ve had to use the Pest Foam to stop mice, but I only need a little bit at a time, the straw gets clogged and it’s garbage. I’m going to get a dispenser gun and the cleaning can!
You’re absolutely right about how the basic version of the product used to expand exponentially more. In the mid ‘80s I had an old car that was so rusted out stuff used to fall out of the trunk through the wheel wells, and there wasn’t much left of the bumper except the thin chrome plating. I filled the entire bumper and the huge gaps in the wheel wells with less than half a can. By the time I got rid of that car it was more foam than metal. I recently used up a couple cans filling just a few gaps (in a house – not a car this time).
Brother I couldn’t agree with you more. I’m a General contractor myself. I own the guns and the products. The red can when it first came out use to expand like a balloon. It should be closed cell foam same as the big gap filler and the blue was open cell foam way back when. This acts like open cell foam and you’re spot on with the pressure in the cans being different.
LOVE LOVE LOVE Jeff and your website. You’ve given me so much great advice and confidence to tackle so many jobs. Keep this coming. There’s no problem with taking some money to show us a product as long as they don’t mind you being honest about it and you think we want to hear about it. You got to make a living as you are helping us all out.
I was a service tech, and the key I learned for the window and door stuff is not to fill the gap completely and just let the stuff expand. It is low expansion, in that it only ~ doubles in size vs the professional spray foams that multiple by 5-10x. It’s better to go back 10 min later and apply a little more than to overapply in the first pass. The stuff is really annoying to scrape away, especially when you’re dealing with visible parts of windows that you don’t want to damage with an Olfa knife. I also learned the hard way why to always leave a 1/4″ gap on all sides of a window when installing it – you have to have at least the size of the spray foam applicator tip!
Thanks for demonstrating why the gun-applied foam works better. FYI: Great Stuff Pro (red can) is only about 80% closed cell content, and although I’ve not found any specs for the non-pro version, it’s probably safe to assume it’s closer to the HandiFoam equivalent, which has only 67% CLOSED cell content. Some other brands, such as Loctite Titefoam and Draftstop 812, have a finer cell structure, higher closed cell content & better R-value per inch.
Hi Jeff, I live in NSW Australia in a semi cold climate area of Lithgow, I’m a new homeowner of a 1950’s house which I have started some budget cosmetic fix ups… Paint, replace skirtings & architraves, replace rotted wooden windows with aluminum… etc etc… I’ve decided to do up the laundry as it is an eye sore, it had exposed plumbing coming in through the asbestos walls and a plain laundry tub… the asbestos has been removed from inside from walls and ceiling and disposed of correctly. I have had the plumbing redone and ready to put Hardies Blueboard on walls and ceiling instead of gyprock being a “semi wet area”… I want to insulate the walls and ceiling… My dilemma is, the house has a metal corrugated roof with no sarking… just exposed metal underneath… (that’s the 50’s) I want to insulate it somehow on a budget and cannot afford to lift the roof and apply sarking to just 4sqm of ceiling… I’ve got to somehow eliminate any airgap between the metal and any of the insulation because of condensation… there is only 140mm of ceiling space as the back of the houses’ ceiling is slopped… Similar to a Vaulted or Cathedral with no exposed rafters after it has the ceiling go up… Could I use a few of these cans to spray between the rafters including between the rafter and the angulation of the corrugated metal roof to get the job done… apologies for being longwinded, I ask as I’m on a very tight budget as I’m supporting my wife’s cancer battle, and not much money is left for tradesmen.
tip: in filling a big gap… have material on hand to temp. close the open side… once the expanding foam is introduced close the open side and secure… this will cause the foam to expand into the tiniest spaces (100th of an inch).. without this block it will actual form radiuses in the corners and the pressure of the expansion will just billow out of the area you’re trying to seal
I recently used a liquid styrofoam filler in the base of my mail box and it was incredible. The new mail box post is in the ground and tighter than it has ever been before when I used concrete. If you want a real thrill, try putting a fence post or mailbox post in the ground using styrofoam instead of concrete. It worked like a charm for me. Wow!
I have to refill a section of my exterior hot tub due to a leak, affecting a fair amount of spray foam which had to be removed. What do you recommend for a larger open area(2-1ftx3ft sections) and what to use to clean the spray foam off a collar of a jet head to remove and replace the seal from leaking?
I am using the pro tip, like you show in the break, and despite it saying no need to shake, I have found shaking it for 30 seconds before use provides a much larger expansion. I love this stuff too. I also used it for Pest control with just the normal foam, and it worked fine… the critters don’t try to dig through.
Jeff, you are the best at what you do! I have learned so much from you as a handyman and have used a lot of your techniques to earn a living. Your honesty and straight forward, real-talk is what sets you apart from all other contractors. 💯 Stay real! Keep up the AMAZING work! Also, to Max, amazing articlegraphy and you’re a great assistant to your Dad. Keep up the awesome job. Thank you both for sharing all your great work. It’s very much Appreciated!! 👏👏👍🏼👍🏼👊👊 Out of Brampton, Ontario Jerry
They are different once they dry. They will have different textures and density. They also continue to expand for several minutes after placing. We use them on high rise form work a lot. I’ve probably used 20 different brands and some are impossible to remove after cured and some just flake off. The Hilti brand will stick to anything, like oil, wet surfaces, paint, concrete, steel, you name it. However if you need to clean up the area around the work later your going to hate yourself for using it. And a pro tip: either wear close you don’t like or something over them, because if you get this stuff on cloth it will never come off. Your better off letting it dry without touching it and try pull it off after than trying to wipe it while it’s wet.
When I was at McLendon’s they said that the window one, once dry, was still a bit squishy and would allow the window to expand and contract at a different rate than the wood around it. This could be a difference that you would not be able to see just at the expansion rate. You’d have to test how squishy it is after it dried.
Per your critique that the lines of foam all expand to the same size: The instructions on the can that I just bought (Sep 2021) of Crack and Gap filler (the red one) say to shake the can for at least 60 seconds. Since you didn’t shake the cans, could that be why your foam lines didn’t expand more satisfactorily? Maybe unrelated. But I also notice it takes many minutes for expansion to complete. Thanks for the tip on how to clean out the distributor!
There’s definitely a difference to them. The window and door is a lot softer than the normal stuff and it doesn’t expand a lot. I would never use another of the options around a window. The regular stuff and the pest are much harder once they cure, and they expand with significant pressure (they will bow 2x4s if they can’t find a release point). They all have similar chemical components but they have been formulated for specific purposes and shouldn’t be interchanged (fire block, pest block, original gap filler, large gap filler and door and window).
There are differences in the foam… Window and door: softer and won’t bulge your door frames Window and door Pro: same stuff but cures faster Gaps and Cracs: regular foam Big gap filler: expands much more. Fill two same sized containers with it and regular stuff, then see which one will cure bigger(it needs to cure to get bigger) Pest block: regular gaps and cracks but with a bittering agent. I know because I work at the plant that makes this. Also, moisture in the air dictates the outcome. Water initiates the chemical reaction that cures it.
Jeff, If you are looking for a difference – you need to do a DIFFERENT test! Your “expanding foam drag race” did not put anything under compression!! Get 4 empty paper milk cartons, fill each one with a different type of foam. Now close each milk carton tightly! (You may need to use some sort of a clamp or clothes pins to close each carton tightly). You should find the 3 times expand foam BLOWING OUT the container. You should also find the window and door foam NOT distorting the empty paper milk carton (or at least not so much). OK, so there you go, now you have an idea for another test and another article – Have Fun!
Thanks for the review! Generally I’d use the same foam for almost everything, but I do use some specific kinds of foam in certain situations (I am doing a DIY renovation, in Europe): – When going around an electric box or near electric connections I use fire-proof foam (it’s the same, but has an additive, it is 3 times more expensive though). – Sometimes I use a specific foam for doors & windows, even if it expands at the same rate or similar one, the difference is noticeable a while after, it’s kind of ‘denser’. – When renovating roof curved tiles, you can use foam to ‘fix them’ together, there is a specific one that doesn’t expand as much as the regular one (so it won’t “lift” the tiles or expand until visible). There is one i’m eager to try but hadn’t had a chance. It states that you can put drywall in place in like 60 seconds. I don’t know if it’s the regular one “with a sticker” on it, but the idea is that you put the foam in spots or lines (kind of what you did in the article) in the drywall and/or the surface you’re installing it onto, wait 60 seconds to let the foam expand, put the drywall on the wall and let it dry. I guess it should work pretty good for old rock/brick walls being renovated (I don’t like connecting the drywall with gypsum compound, due to gypsum being “thirsty”). P.S. in difficult locations, I attach a hose to the end of the can pipe (or remove the plastic pipe and replace it with a hose), that way I can insulate very narrow spaces and be able to hold the can upside down (there is one that works upright, but costs like 3x the price).
Very helpful! And if it might be of use to anyone, I used a can of previously used Great Stuff Windows and Doors foam from about 11 months ago today — no problems at all. I had used it with the pro gun. After use, I removed the can, cleaned the gun with the Great Stuff cleaner, and then put the can back on for storage (as Jeff demonstrates in this article!). I was surprised it worked because it says to use within 30 days of first use on the can.
Thanks again for taking the time to educate us on the use of spray foams. My guess as to why the foam’s characteristics have changed over the past 10 years or so has to do with US EPA air emissions regulations. Currently, these foams use butane and propane as the blowing and puffing agents. I know many years ago (perhaps more than 10) ozone depleting refrigerant 12 (R-12) was used as the blowing and puffing agent. Also, the EPA currently allowed volatile oraganic compounds may have required a formulation change in the foam base over what was used 10 years ago.
The red can in the pro one is a fire blocking foam. (In the US anyhow.) I go through cases of it a month. I own an insulation and air sealing company. There is definitely a difference in the formulation of the window and door vs the fire blocking foam. The window and door one is a lot more pliable, the large ones cure really hard.
Love this article. The sad fact is that Great Stuff foam is hardly the only company that’s pulling their marketing BS with their products. An INSANE amount of OCD-laden research goes into consumers wanting to make sure they purchase the “best” product, and in so many circumstances they get caught up in this marketing crap, because we don’t know any better until we’re up to our necks in the project. So, the pro’s who are in a position to know….their feedback is absolutely priceless. So, a big thank you again, to Uncle Jeff for his time, and wisdom.
I’d like to foam around the rim joists and sill of my house. Would you recommend Great Stuff Big Crack for this, or us there a more cost effective option. Is this foam a closed or open cell product? Contractors want a ridiculous amount to do this. It’s a simple job – but I only want to do it once. Thx for your help.
This guy is my hero! As a contractor it sucks working for clients, to be able to shut down ur business and just make articles of you working on your own home for yourself (every contractors dream) just amazing i gotta hand it to you, keep the articles coming, no more crappy days for you! An inspiration to all trademan who dont want to be swinging a hammer into their 60s…
So I’m a long time viewer, seen every article and love them all. I have this problem though that when I get around to finally doing the project I’ve watched a article about, I can’t remember some of the fine details. I get into the isle of home depot and I’ve got a 4 hour drywall article to scrub through to figure out the mud options I’m looking at. It would be nice to have a little PDF for each topic that outlines some of the article. It would absolutely be worth a couple bucks to me. Like for the drywall it would have been nice to have a refresher about the mud types, a set of recommended, optional, and necessary tools and products, and a brief outline of what to do. Thanks for all you guys do!
What can I use in between my regular window and storm windows? Because the insects are getting in since its not fully sealed. I think the windows are very old, Its aluminum . We just move here a couple of months ago. We were told by our inspector that we have good windows but doesn’t seem to be since we feel a lot of air coming in during a cold weather. It is not energy efficient at all. Thanks for your help. Any suggestion will help.
I would just like to know how YouTube managed to get a article on expanding foam when I mentioned it to a friend of mine the day before you know it’s just so amazing how YouTube just knows exactly the Right article to put up at the right time. It’s almost as if I’ve got a microphone attached to my ass or something or somebody’s following me around or somehow being monitored or something I just wanted to bring it up I thought maybe somebody out there might come across the same scenario.
I too remember as a teenager using this stuff with my grandfather maybe 15 years ago and the gap filler absolutely expanded like crazy, but I think even the regular version expanded more than it did in your test. They’ve probably found a cheaper way to make it so they can profit an extra Nickle per can.
I use to use Great Stuff foam, but when Loctite came out with their foam solution I immediately switched. Great Stuff isn’t so great. They have definitely come a long way, especially with their “one-time use” can, but I can’t stand that when you have to spray something where it will be visible it dries an ugly yuck brown/yellow color. Loctite is white and dries white, it is also my second go-to. I use Rigid All Season Crack and Window and Door. Their solution, their cans, their guns, and their cleanup spray is rock solid. They’re more expensive then Loctite and Great Stuff, but you get what you pay for.
Ok… Where is the camera in my office?! I was literally reading the instruction sheet for the Great Stuff Pro 14 foam gun when I looked up and saw the new article land from you guys! Only question that you didn’t cover regarding the foam gun is the added plastic tips, are they used or do they serve a purpose?
I was wondering myself about the lack of foam in the Big Gap can. When this stuff came out about 25 years back I used it to fill a void between joists. It must have grown to 50 times its initial spray size. I had to cut away a ton if overfill. But it was definitely giving my monies worth. I could have done a complete wall with a can. Now they detuned it to only give you a little and hope you run out to buy more!
I have used that stuff for years. I believe the difference in your test, from real application, is restriction. In your test it is simply applied to a piece of OSB. There are no barriers so the product has nothing to build pressure against. I have never tried it, but it would be interesting to see what happens when an (as close as possible) shot goes into a balloon. From my experience, there is a real difference in product when applied in a restricted area.
You know, aside from the pest-block or fire-block line they offer, I’m really glad to see I’m not the only one that had that “Wait… What the hell happened to these other ones?” reaction haha. Feel like no matter which one you pick, you end up using the same amount of cans to fill what you need to. Personally I just stick with the window/door flavor for the same reason you showed – easy to control
Hi Jeff, my name is fabian from Montreal. I am in the process of purchasing a 2 story house. There is many structural weaknesses. The floors on the second are sagging to wards the middle of the house. The staircase is located in the center. I am going to change the center beam in the basement and on the 1st floor. I have pictures and would like to send them to you for your advice thank you.
I’ve long contemplated getting a reusable gun and this almost sealed the deal. I noticed though that the one-time foam cans (usually 12 oz) are cheaper by the ounce (roughly 2.50) compared to the larger pro cans (roughly 20-24 ounces at anywhere between $9-14 a can). So the reusable gun is great if you can’t go thru 12 oz at once, but otherwise cheaper going the one-time use route…
Jeff I love your website. I used to do carpentry when I was a kid (framing). I’m 67 now and starting it again as a hobby, and just to fix things around my home. And typically I don’t trust most of the contractors in my area, as they aren’t as good as advertised, they do less than stellar work and expect premium dollars. So I’m catching up on 50 years of changes and really appreciate your efforts.
I used all four kinds recently and they all expanded quite a bit except for the window foam. It came out the least dense. The pest block was super dense and the fire foam expanded the most I feel. I used pest block for most of my project then switched to the regular red gap filler cans as they’re the cheapest. They have new tips now too so you can close the tip and reuse it later.
That spray gun, to me seems absolutely necessary. I recently used two cans in my attic and to make a dam for concrete self leveling a floor. Their standard straw is impossible to control your beads if you require precision. It’s messy and completely impossible to control. If you are filling gaping holes and don’t care about aesthetics (and will be covered up) that is a different story. I wouldn’t use this foam without that gun next time around that looks amazing. Also use nitrile gloves when spraying.
First off Jeff thanks for all the great articles, a quick question, this past winter we discovered a significant flow of cold air coming in through the bottom molding around our windows, but I get conflicting advice about removing the molding and using low expansion spray foam vs stuffing fiberglass insulation into the voids. your thoughts would be appreciated.
In cold winters below -10 degrees C, I had frost at the wall corners and a small area on the ceiling inside my closet. I found out that The batt insulation at the wall corners were missing. The fluffy insulation at the attic was missing near the corner. Instead of cutting the whole drywall open or climb up to the cramped space in the attic, I drilled holes on the drywall at about 1 inch apart. Then I inject Great Stuff inside. After the spray foam solidified, I cleaned up the holes and finished the small areas of drywall using drywall mud and then primed and painted it. It was successful. No more frost again even when the outside is -30 degrees C.
Pest wire mesh then foam…rats are smart.. and hard to get rid of… some places foam wont work..wire mesh sure will… remember roof vents rats lift them for entry…just wire mesh over entire vent in attic.. yes it took months to rat proof home..pest guy kept telling me more areas to seal.. attic..cornors..garage..venting for stucco siding.( a ranch is a lot to wire mesh to do).. look for greasy dirty areas.. but when done you out smarterd a rat… a great thing.. garage staple wire mesh then foam or mud.. I hate rats..but will do what’s needed to stop them..
Thank you. Appreciate the truth finally. I do remember when that stuff would expand and bow the frames. I also thought the found a way to stop that and sell another type of can that still expanded. What load of Crops. Does that pest control smell different than the other stuff? if so, is the smell tolerable or overwhelming?
For the pro bottles it seems that the gaps and cracks is very similar to the window and door mixture, however the big gap filler as I understand is the only kind of foam that is a closed cell type which is actually more useful in a lot of instances. I personally would prefer if they sold the big gap filler in the pro cans. I usually purchase the foam for air sealing purposes and have a can of window and door I re-use and on occasion when needed I will get a throw-away can of big gap filler. It seems the products may have changed or it’s possibly because I am in the US.
At 2:20-ish, you say that these cans do not need to be shaken & that the instructions to shake have been removed from the can. They have NOT been removed from the can! It clearly states on the basic (red & black) product can (and I bet all the other ones too) that you need to shake the can for “a MINIMUM of 60 seconds”. Maybe (or maybe not???) this is why the products demonstrated in this article did not demonstrate the way you thought they would (you said it was sort of underwhelming) >>>because you did not read the directions and/or shake ANY of the cans (as the instructions say) before use <<
This article is so informative! Thank you!! If you could share your opinion on my outside the box idea, I’d be so grateful! What about using this on a small leak in a basement wall that’s below grade? Could we maybe drill a hole where the leak is, then point the spray gun as far as as possible through the hole, then spray it through the hole to seal it from the outside? Or am I just looking for trouble? lol. I know there’s a “right way” to go about sealing basements, but there’s also limits with finances and abilities. I would of course, tuck point with mortar in all circumstances. I’m just looking for a way to come from the inside and seal it on the outside. After looking at how people do waterproofing with a spray nozzle to do a “curtain seal” with polyurethane foam and other gel type substances, it’s got my gears turning about maybe doing something similar without spending a fortune on equipment or contractors. If you have any other ideas, I’d love to hear them!
i have an idea that the old high expansion foam caused problems, like windows and doors that were affected by the preasure created by the expansion being too great for the application. I have been using this Great Stuff for years, and I have seen a change. It is less likely to over tighten a window, door, … What you might want to do is cut those different gobs of foam and look inside at the size of the air bubblles inside. Also you might want to use it how it is actually designed to be used. Make yourself a plywood box with the inside dimensions 2 inches wide, 6 inches deep, and 12 inches long, kinda like an opening of a 2 by 6, 12 inches long. That would show how it is actually applied in the field, and the difference. The open air is setting up the outer shell, not letting it set and expand like it was designed. Just my opinion. Thanks for the articles
I used to use only one can and then throw it away. The solvent is amazing idea. I don t do enough to buy a gun. But the solvent caught my peepers. The only failure i had with this product is i sealed a gap outdoors and it worked for weather. The squirrel however, ate the stuff and just sent in a gap so small i thought impossible. So watch out that this works for weather not pests.
I was surprised too when I saw that they all had the same expansion, more or less. Only 3 years ago I insulated the ceiling of my garage with the blue can and the foam was very hard to manage, especially along thin gaping holes. It came out at high pressure and large bead (maybe I cut the tip too much) and then it kept growing and growing, at least 4-5 times the original stream. You raised a very good point.
I’ve been using this as an off label sheet rock or plasterboard fixer for about 15 years. However I used a metal gun that takes replacement canisters. I have even done a couple of ceramic tile splashbacks. For the plasterboard, it also makes an excellent packer where old framing is buckled. When the fixing screw starts to deform the board, you just undo the screw, squirt in a dab of foam, then redo the screw hand tight to hold the plaster board flat while the foam expands and sets. later you just screw in with your cordless drill. Makes an excellent wood glue for building forms, too.
I thoroughly enjoy the content you guys put out but this one is a bit ridiculous. Testing the foam by spraying a 1/4 bead isn’t the right way. Build a box with a few 2×4 studs and a plexiglass front, and actually spray some foam. The difference between the Big Gap and the Window & Door is night and day. Telling people there’s no difference between them is going to cause people a lot of trouble.
I’m glad you finally did a article on GreatStuff foam. I used it initially, but I would agree with you. It’s not that great. At the local big box store in the states there’s GreatStuff and Loctite Foam. Before Loctite I wasn’t even happy with GS but there were no other products. I hated that the foam would change colors in certain weathered conditions. I know you’re not suppose to use it outside, but to fill holes temporarily until you could patch concrete so that pests wouldn’t get in (this is before their pests foam) I would fill a hole. But the characteristics of each foam seems to be the same. They don’t all expand as much as you would think they were rated for. I immediately switched to Loctite when it was introduced seeing right in front of my eyes it did what it said it did. They now have regular, big gap, and window/door. The downside is they don’t have positive tips nor gun handles. In certain situations I have also used Rigid foam and guns. But they’re really expensive, more than GS and Loctite put to together, but got a couple cans from a friend who’s a professional when it comes to insulation; but having to go out on your own and buy the same cans to keep consistency when you ran out is pricey. Rigid foam all works and performs as advertised.
I’m pretty sure you still need to shake it to help with expansion! It’s also possible they had to change the formula to work with the new dispenser. The original red can used to expand an ungodly amount. Way too much, most of the time. I always go for the blue can. It’ll work for most applications and is easier to work with.
Jeff is usually one of the “most” straight-shooting DIY “advisor/contractor”-type guy……HOWEVER, I was disappointed to notice: NO SAFETY GLASSES while spewing these high-pressure “uncontrollable” POLYURETHANE FOAMS?? That “stuff” adhere to HUMAN SKIN instantly, and cannot be removed. It has to “wear off”. Wonder how long it takes to “wear off” an eyeball/cornea??
I appreciate and trust your information even more, knowing that you’ll continue with your failed experiment, and then address the issue. You should reach out to them with your concerns. If your concerns are unfounded, they should have no issue at least providing the correct information for your subscribers, or maybe even fly you down to educate you on their processes and methodology, for our benefit. Either way, if you love the product and have had no issues using it.I trust that the core product must be good.
Hi, I was wondering how to remove dried/cured spray foam. I accidentally sprayed next to a newly installed shower base to fill a gap and did not expect the foam to expand as much as it did. It basically crept up the front side of the shower base and left behind a film after o removed the bulk of it. Any ideas please!?!
I recently purchased this: “GREAT STUFF PRO Great Stuff Foam Sealant Kit – Great Stuff Pro Pestblock 20oz, Great Stuff Foam Gun, Great Stuff Gun Cleaner 12oz, Great Stuff Gloves, Copper Mesh. Green Color, Spray Foam Insulation” WHEW💨 that’s a mouthful! I was looking for more information before I apply this when I found your website. I have to say I am a little more than underwhelmed with your demonstration, or with the product, I mean. I used great stuff back in the 80s on my garage and my unfinished basement and to echo what you said, that stuff had far better expansion than what you’ve demonstrated with this stuff. Now, Both of the cans that came with this kit say to vigorously shake the can for 60 seconds before using. I don’t know if that’s different than the stuff you used that doesn’t require shaking, but I don’t know how this stuff can seal very well or cure very well, if it really isn’t going to fill the gaps! I’ll try to edit this comment with more info after I’ve given it a shot. But I appreciate your article and your attempt to assist us with these products. Wish me luck!
I enjoy and learn from your articles, thanks. I agree it looks suspicious and the original version blew out everywhere the first time I used it. I think the only way to know for certain would be to spray a full can of each type (if the are the same size) into large balloons or through a hole into a closed cardboard box to see if there is any difference. It looks to me like the large gap type is under a lot more pressure and since it isn’t contained the blowing agent just escapes. Maybe try the just large gap vs window. I hope there is a difference I don’t like to believe I am being ripped off. Thanks again for making these articles.
Hey Jeff, what do you think of the large DIY spray foam kits? They are about $350 at the big box stores, and claim to get 200 square ft. out of them. Wondering how they would work for insulating rim joists? Also, what is the most efficient way to do this? Thanks. Loving your website and articles, by the way!
I’m trying to find something “stickier” then this product in Wikipedia, and the 14 volumes of the history of man…..and I haven’t found it yet…. I heard that one time they exhumed the body of an old contractor, dead over 30 years, and they actually found “Great Stuff” foam stuck to his fingers and hair…..It was disturbing….😂
You mentioned in your article that it seems that the material does not expand as much as it used to. I agree. I just bought a can of Great Stuff Big Gap Filler. It hardly expanded at all, maybe 25-50%. I estimated the volume of dried foam from the 12 oz. can that I used – in the neighborhood of 0.23 cubic feet. Same as 400 cubic inches. You could fill a 1.25″ gap in an 8-foot 2×4 wall. $11 per can is pretty expensive to fill that gap.
Awesome article. In the same vein, I would like to see the article DYI spray foam for whole wall. I know we can buy the “Part A/ Part B” kits at Lowes/Rona/Home Depot/etc…the canisters and spray nozzles and such, .but it is really something a DIY can do, or is it something really best left to professionals.
Man you really took me to school. I’ve been using this stuff for years (red can). Haven’t used it in a long time. The last can I used I sealed a mouse hole (They really hate the “Stuff”). Used it once, tip dried & clogged and was “Donezo”. Wouldn’t buy it again unless I needed to use a/l a half-can. Now this new stuff has reusable tips. That’s Godsend. Thanks Reno’ Man.
I takes work and time to review, practice, purchase product, set up camera(s), tri-pod, lighting then edit & upload. Since Sept 2020, depending on where you live, but Dow sells “Fireblock” and others. I am sure many have told you about using acetone to clean the handle and straw. I am not a contractor but an auto tech who had to retire 11+ years before it wanted or planned. I am glad I watch just to see the metal spray nozzle, and one in plastic! Never seen these, but not looking. I think clean the can valve with a little acetone is worth a try. I can move a ladder, climb and spray before it hardens. (Bad elbows & too many back/fusion surgeries) I appreciate the “Distance” spray. I found it amusing. Once when younger, I could wizz over a Buick without getting it wet. Not anymore. Oh Yes: Spray bottle with water will stop the expansion. I am dealing with a new phenomenon in the upper central Midwest; “Woodpekerizm” …Sounds like I should see a Dr. When working and having money during the 2005 era, I had Exterior Insulation Finishing System or EIFS. I saw it used on hotels and commercial buildings. Doing research as always, I made plans to reduce energy cost as you can’t get that back. So worked perfect, looked great and no future painting. Then wildfires and smoke drove woodpeckers into our area. Normally looking for food, one decided to make a nest. You guest it, I now have holes both shallow some deep. So spray the “Critter” foam, hit it with water, a 4 1/2″ angle grinder allows a depression to fill with treat fiberglass cloth, into a bed of concrete using a Red Plastic tape that works great.
I have a similar beef with product lines from CRC and Selleys here in Australasia: so many different and seemingly needlessly specialised products. Even good old CRC 5-56 penetrating lubricant you now have to choose between multi-purpose, electrical, industrial, low-odour, marine, food-grade. Can I not use the multi-purpose variety for electrical or industrial applications now?
Hi there from NZ. I hit like and subscribe buttons in the first few seconds when I saw you were a Tradie and knew what you were talking about! Thanks for the great article! You are right…I remember when gorilla foam first came out. It could fill massive gaps and you got a lot more than now out of the same can. I was thinking the same thing…do you really need 4 different cans? It looks like a sneaky sales gimmick to lower the pressure, change the colour and put a cheap additive in. And, hey presto…you have 4 salable products! I just want some insulating foam that works!
Great article, thanks. I would like to have that gun. But plastic tubes on cans I’m buying are around 1/4″ and I can reach inside much deeper on smaller holes. It would be great to have ability to snap plastic tube on the end of that gun if needed. Also discovered some time ago foam which get so hard, it feels like solid material after curing. In your article you didn’t show what property stuff have after curing. Soft? Hard? easy to brake of? Cut? Pliable?
I’m late to the party. I have not done a comparison of every product, but did a side-by-side using the SDS for the gaps and cracks to the pest block and the composition/information on ingredients in the SDS for each was identical. Between these two one would assume a difference, but I did not find one. I only looked at these two because of the project I am doing. I would like to see a response from the manufacturer of GREAT STUFF on the difference.
Could you PLEASE add some of this stuff into a mold and then test the durability such as stiffness and waterproof factors once fully cured!? Looking to use this to make foam “boards” that can be shaped since similar products are near impossible to find at an affordable price in my country… Unfortunately my budget for this project is incredibly tight so any type of experimenting I can cut out would be much appreciated!! 🙏
I’m in the market for some “Great Foam” and a gun. I’ve never seen watched your articles till now. It can be very tedious perusal how to articles. I realy like how you come across. Seriously! You get right to the point saving us all time. Your demeanor very plesent. You say what you think. Rather candid making it easy to comprehend what your wanting to explain. Being this way as it is. Your delivery boarders on comedic. That’s why I enjoy perusal you. Attemping to learn something more about a product etc. I’ve only watch one of your articles and I got all this. I want to buy a gun to go with the foam. I always read the comments which is a huge influence. If most or all coments are neg. I’m not buying that product, I’ll buy a cheap foam gun. $15.00 $20.00 bucks no more. Is this a mistake? If so then I’ll likely stick with the straw. My goal is to devert the rain water away from the foundation and trickling under the house. I recall using this foam oncealong time ago Please advis on the gun please.
I use this product every halloween. The trick to using this is to spray the foam, mist with water, mist y😢gloved hands and wait 5 minutes to form a skin. Then you can mold it slightly. The water will prevent the foam from sticking to your hands. If you’re going to use these products, the window foam is smaller than the big gaps products. Squeeze the trigger slowly. This will help to control the foam
Call me crazy!. I have been working on my truck for 10 months and I e been spring caned fome in all the finders and filling the are spaces under it.. It’s made my truck So much solid quitetar it handles better. I get what is on sale and I don’t see why differents in it at all other then coler . I have so many cans spread under that thing it will float and it is so much quiteter my staryow sounds KILlRR l got my door full 1/4 panels full You would not believe how much difference between now and before it is HUG!!! Have a great day!!.
I agree, just bought a big gab 2 days ago and there was absolutely no difference between the regular and the big gap, and I paid over $17.00 for it at Home Depot . I think it’s just an advertising ploy for more money but same product . Now you can get Spey foams in many other brands so will try a different brand next time .
LOL, My little bro worked for Equate 20 yrs ago where they manufactured the Equate brand shaving cream and he said the only difference between regular and sensitive skin version was the label on the can and he wasn’t joking. So companies have been falsely marketing their products like Great Stuff for a while.
Funny to watch people screwing gun in an attempt to seal it for storage. The screw on the gun is nothing but a trigger stopper, meaning its position does not play any role unless you engage the trigger. Reminds me of folks who dial their car AC setting low thinking this will increase cooling rate. Also, a bit of education, if you want to make a point of not having a difference between products, you absolutely need to show Section 3 of (M)SDS document for the product, which is available even on Home Depot product page. I checked them and I do not see any difference, so they are likely not any different, but it would be much stronger/professional way of comparing products. Now, I do not know if it is a requirement to list bittering agents in Section 3, I assume it is; so whoever is saying there are bittering agents in Pestblock should really think about why this is not reflected in MSDS.
I got this DAP Mouse & Pest Shield with Pest blocking foam (Green & yellow label can with a pic of a mouse) at Home Depot because it was on sale. It sprayed Grey and it had a strong smell and I have not been able to find it again. I did not know Great Stuff’s pest foam was also for mice as I am having a rodent issue and I was using foam as a quick DIY solution. The other regular foams, the rodents have chewed their the foam, including the grey one with the funky smelling pest shield (although that one took a bit longer)
Lastly. Don’t buy a can for 1 use. Wait till your list builds up. They aren’t gonna smaller single use cans. They will sell you an extra trigger straw. This way you walk away thinking you’ll actually get to use the whole can unless you spend extra on their “reusable” straw. The marketing president needs a raise. No we don’t make smaller cans and sell for less. We make them pay for the straw and swear it can sit for a couple days between use. They’ll never have a second project before can hardens. We sale peace of mind. Not an actual useful item. Not really for the host. Great article. Great layout. Awesome way to avoid any flaws. You did well. I hope great stuff hears the cry. Also. Make every supplier carry the black label outdoor use foam. I for one love how they cornered the market. Monopoly at its best. Sneaky.
My father used the stuff that “blew up” and went into a crack and expanded like huge clouds of bubble gum… I need some of that today. Is it anywhere?? Thanks for this article, I was surprised to find this content online and it truly helped me figure out this isn’t the expanding foam I thought it was.
I’ve had those expensive professional tips plug up and become unuseable too, and yes I cleaned it and used their cleaning solution. Sure they give you a little more control but for the price I’d rather just buy 3 of the cheaper cans. And yes Jeff, none of these spray foam products seem to expand like the older spray foam products use to. They all seem to be about the same now. I’m pretty sure it’s a marketing scam and they formulated it that way so you just have to buy more cans to fill a give volume. Think of it, if one can of product could fill the same area as four cans of another product most people are just going to buy that one can instead of four cans of the the other, but now you have to buy four cans instead of just one to fill that given area.
Hi! Been perusal a lot of your articles this past few weeks, hittin’ the thumbs up button on all of them. I’m getting ready to work on my unfinished basement, and plan on buying a steel foam gun. Since the cans need to be upside down, and I’ll need to spray around the extruded polystyrene foam boards within the rim joists, is there a flexible hose that can be used to get the job done? I’ll need it to work around tight spaces where the water pipes are in the way. I looked around and couldn’t find any. Your assistance would be greatly appreciated. Thanks, and keep these great articles coming. Love it!
Some modern products seem to have been ‘updated’ to be primarily useless. I just bought a can of fly killer spray. You can kill flies with it – spraying them doesn’t seem to work but I guess if you hit them hard enough with the can it would kill them. Thanks for the warning about that brand of (allegedly) expanding foam – what an absolute waste of time – best way to use it would be to jam the cans in the gaps you want to fill.
Why is the can held upside down? Please move the cans more slowly so it’s easier to see what’s being done. Also, when holding (and resting) the cans please show the front of the can instead of the “small print” that cannot be read. The part of the “cleaner” can was particularly fast and it wasn’t until 30-45 secs later when we could see what the front of (name on) the can could be seen. Otherwise good comments. It would have been great to see an example of filling in a crack/gap and then see how much it expands in the gap and then how to trim it appropriately. Again, ok commentary.
I 100% agree about the expansion. I was just using some of it myself and am not terribly impressed. I remember years ago I used some of that big gap filler somewhere and stuff expanded like crazy. I’m currently filling the gaps between my windows in an old house where I don’t want to cut the plaster. I’ve just been drilling small holes into the wood part of the frame and wanted to spray it in like that but seeing this I’m wondering if it will even do anything! Any other company make this product that anyone is aware of? I’m seriously not impressed with this product.