Fiberboard is a versatile material that can be used as an exterior wall or roof sheathing, particularly in cold and humid areas. It is designed to strengthen the walls of a home by preventing wind and water from entering the building envelope. Fiberboard sheathing is used to insulate walls and roofs while providing structural stability and can also be used for decorative purposes.
The optimal choice for most homes is oriented-strand board (OSB), which is a wood product that is earth-friendly and can be used as a base for framing studs. While OSB ties framing studs together, fiberboard sheathing provides insulation value. However, most structural exterior wall sheathings lack insulation value.
Foam offers no structural benefit but adds continuous exterior insulation from R-5 to R-10. Alternative methods to meet brace-wall requirements include shear-nailed 1/2-inch fiberboard. Both types of sheathing attach to the exterior wall framing and brace the walls against positive and negative forces. Fiberboard can replace corner bracing when applied vertically or horizontally to the wall, but it may not be suitable for all applications.
While plywood and OSB are structural and offer substantial racking resistance against wind load, fiberboard is weaker and does not increase the racking resistance. High-density cement boards can be used for building exterior walls and floors, as they are fire-proof, moisture-proof, and heat-insulating. FiberBrace claims it is an ideal sheathing due to its structural, breathing properties, and lightweight nature.
In summary, fiberboard is a cost-effective and effective option for both exterior wall and roof sheathings, providing both structural and decorative benefits.
📹 Rotted Wall Sheathing
Structure Tech home inspector Reuben Saltzman pulls back some vinyl siding to find rotted wall sheathing behind it.
Why is fiberboard not recommended as a modern wall sheathing?
Fiberboard sheathing is a type of sheathing made of wood fibers combined with a binder, providing moisture and fire resistance. It has a higher R-value of approximately R-2. 5 per inch and a perm rating of 5 to 20, depending on the manufacturer. However, it does not have good shear strength and usually requires additional bracing. Some fiberboard products are rated as structural sheathing. When installing new, manufacturers recommend adding a house wrap or other water-resistive barrier (WRB) as soon as possible.
Fiberboard has been popular in North America since the 1950s, but has not been used in new construction since the late 1990s. It was purchased as an alternative to plywood and OSB during the spike in lumber prices. In some cases, fiberboard was installed without a house wrap, but in others, it became a condensing surface during winter due to an air leak. This led to questions about how to install new windows or tie in additions with fiberboard, as well as how to ensure continuous water and air control layers.
Is fiberboard weather resistant?
Fiberboard sheathing, originally designed for interior use, can break down in the sun and rain, curling up and swelling if left exposed too long. To make it moisture-resistant, manufacturers treat the board with a water-resistant surface coating, such as wax or asphalt. The problem with swelling and warping occurs at untreated edges and cuts, and UV rays degrade the surface. The material has existed since 1772, when Henry Clay patented a paper-based fiberboard for interior walls and door panels.
Major brands of fiberboard include Celotex Fiberboard, Homasote, and Hardboard Masonite. Early fiberboard products were made with fiber materials like jute, straw, sugar cane stalks, flax, hemp, grass, newspaper, and peanut shells. Today, North American fiberboard products are exclusively made from wood fiber. In the past, fiberboard was made with sugarcane bagasse and urea-formaldehyde, but some imported panels may contain these ingredients.
Which board is best for exterior walls?
The SHERA board is a durable, water-resistant, fire-proof, and insect-resistant sheathing material designed for use on exterior walls. It is a distinctive fiber cement composite manufactured from natural fibers bonded in a high-grade silicate structure, exhibiting a neutral pH and remarkable resilience to insects and chemical corrosion.
What is the best sheathing for exterior walls?
Structural fiberboard is an engineered product made by grinding wood chips and other lumber waste with wax and resin. It is less dense than wood but more thermally resistant and dimensionally stable, making it more affordable and more suitable for wall sheathing. However, it is less strong than wood and won’t hold fasteners as well. Additional wall bracing may be required to meet local building codes.
Diagonal tongue-and-groove (T&G) wood boards were standard practice for sheathing until after World War II, but they have waned since then. Solid wood sheathing is still a good choice for providing the best structural support, especially for houses in storm-prone areas like Florida. These boards are the best way to tie headers to footers and wall studs together, making them ideal for houses in storm-prone areas. Diagonal tongue and groove boards are also highly durable, with spruce, fir, or pine boards being more resistant to rot and swelling than OSB. They also provide a strong fastening surface.
What is the best board for exterior use?
Cement board, composed of cement, is a robust, moisture-resistant material that is resistant to rot and degradation in damp or wet environments. Construction timber is typically employed as an initial fix and is suitable for stud wall partitioning and general construction. To prevent splitting when screwing into studwork, it is recommended that a pilot hole be drilled and that the screw be countersunk to achieve a flush fit.
Can you use fiberboard outside?
Due to its susceptibility to water damage, MDF is not recommended for outdoor use. However, with the appropriate treatment and care, it can be utilized for outdoor furniture and decorations. It is, however, essential to bear in mind the constraints of the material and to take the requisite precautions.
Can fibreboard be used outside?
Medium-density fiberboard (MDF) is a composite wood product that is primarily used for indoor use due to its moisture sensitivity. However, with proper precautions, it can be used for outdoor applications to some extent. MDF is prone to swelling and warping when exposed to moisture, making it unsuitable for direct exposure to rain, snow, or extreme humidity. To make MDF more resistant to outdoor conditions, sealing all sides and edges with an exterior-grade sealer or paint is crucial.
This creates a barrier that prevents moisture from penetrating the surface, reducing the risk of swelling and warping. Applying multiple coats of an exterior-grade paint or primer also enhances the material’s moisture resistance.
Is fiberboard good for exterior walls?
Fiberboard is a cost-effective and versatile material that can be used as an exterior wall or roof sheathing. It is ideal for cold and humid areas, as it absorbs humidity and releases it outside. Fiberboard is made from plant cellulose fibers mixed with adhesive substances and a water-resistant coating, making it suitable for structural exterior construction. It doesn’t swell or deteriorate with moisture exposure compared to plywood.
A sheet of fiberboard can cost between $10 and $40, making it an economical choice for those on a budget. The top 5 best fiberboard sheathing options are listed below, ensuring the integrity of your house.
What board is used for exterior walls?
Oriented strand board (OSB) is a popular sheathing material made of hundreds of thin wood strands pressed into a board with resin and wax adhesives. OSB is installed vertically over the exterior of a home, providing structural support and insulation. It can be grouped into structural sheathing and non-structural sheathing, which can be used together or individually depending on the building. Both types contribute significantly to the overall structure and function of the walls. OSB is essential for both new and older homes.
How thick should exterior wall sheathing be?
The minimum thickness for gable end walls structural sheathing is 3/8 of an inch, with the exception of 7/16 of an inch.
Can you make fiberboard waterproof?
To make MDF moisture-resistant, you can use high-quality wood sealant, varnish, stain, or moisture-resistant paint. Avoid using waterborne polyurethane as it may not bind readily to the MDF’s surface. To waterproof MDF, apply a latex primer or a primer designed specifically for MDF, using a 3/8-inch paint roller and a paintbrush to reach into areas not otherwise reached. Let the primer dry for six hours. Apply a sealant or water-resistant paint, using a 3/8-inch roller, and paint the corners and edges, taking about four hours to dry.
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The Zip System is great if you use trained installers to do the taping properly. #1 rule is every square inch has to be rolled. That starts a chemical process that melds the tape to the panel. I’ve been doing Weatherization Systems for almost 20 years, literally 10’s of 1000’s of single and multi family projects, using all types of WRB’s. Tyvek, Barricade, Typar, Dow Weathermate Plus, Fortifiber WeatherSmart, DrainWrap, HydroGap, Zip Tape, you name it. Guess what, they all work because they were installed properly by trained and certified installers. I didn’t trust the Zip System at first and resisted it, but after having first hand experience in how it performs, I have no issue with it at all. It is our favorite system to install because it is much faster and has way less damage from the other trades than traditional housewraps. If done right, it is equal to or greater than housewrap. Disclaimer: Dr. Joe is a friend of mine from way back, but I supported Zip System before he did. I just want that on public record, lol.
I won’t say that this system is not what it’s cracked up to be because it hasn’t withstood the test of time yet. But I am not a fan of house wrap. I do renovation and re-hab work almost exclusively and here’s what I’ve found: homes, some as new as five years old, with house wrap are rotting; siding, sheathing, right down to the framing. In some cases poor flashing is the culprit, but not always. The least affected houses that I work on have either plywood or board sheathing with felt paper for wrap. Seldom do I find these houses with any rot above the sill and first few courses of claps or shakes unless there is a drainage problem at the foundation or splash issues. The new homes with rot are as high up as the second floor. Technology is not always an improvement and in many cases more a marketing way of making money. Let time be the test.
My main concern would be that since there’s no housewrap to tuck your window and door flashing behind now, you’re going to have to rely on adhesive tapes to seal out air and water. The question is: just how long does the adhesive last on that tape ? I’m a builder but I never jump on the bandwagon until a product has many years behind it; just relying on sticky tape to weather seal your house seems like trouble waiting to happen down the road
ive installed zip and it is as good as the person installing it. they now have a liquid flash product to use on seams before taping in case of a tape failure (install error) and can be used on over-penetrated nails. i ended up flashing all the nail spots for extra protection. i wouldn’t say its faster than housewrap but definitely a more efficient product when installed correctly
The WRB (weather resistant barrier) plus the fact that this is essentially the same material as the Advantech subfloor says a lot about the product. If you are not familiar with Advantech, go try lifting a sheet of 3/4 material and see how dense it is. This stuff is as close to waterproof as you can get.
I’ve always found it odd that builders are using exposed wood (no bark protection), to cover exposed wood and then adding treated exposed wood to cover the other layers of exposed wood to protect homes from the elements. That has never made sense, nor cents to me. With the cost of wood being the most expensive that it’s ever been the logical explanation for a solution is to start using ICF (at a cost of 5% more on average) and metal studs (which are and have been cheaper than wood for several years now) to build homes. Additionally, ICF and metal stud homes offer so many more benefits that can’t be matched with basic home building techniques. The question then becomes, why exactly are we not building homes using ICF and metal studs since the benefits far outweigh the cons? #ivealwaysdoneitthisway #yeah #thatmindsetneverworks
We put an addition onto our house in 1989. We only got as far as the tar paper and I believe the layer underneath is gpyrock. We’ve had no issues until now. A piece of the tar paper was torn off and something bore a hole 2 inches in diameter right through the gyprock. It was done sometime in the last 2 weeks. I have done Google searches and only see small pests (insects: listed. I’m wondering if this could be a rat? I don’t know how to fix the wall because I don’t know what attacked it. Thoughts? Would this new type of sheathing guard against it?
doesn’t matter how good they engineer things…. idiots will always find a way to screw it up. If you don’t tape correctly it becomes the achilles heel of a zip system. My personal belief is the closer wood is to a tree the longer it will be on that house because it can breathe/drain better…… the closer to mulch or sawdust the faster rot will set in and turn it into rot and dirt. Any gardener will confirm that assessment. All that can go out the window though if you seal it up like a boat, once water goes down in and cannot escape the house… its a goner no matter what system or methods you use. Look at how long older houses stand the test of time vs these newer homes slapped together last… 5 years or less and they have to be redone.
So if your going to shingle the roof and let’s say you had to flash it, usually the Tyvek would go over the flashing so water can’t get behind it, with this system, I suppose all you can do it use a good sealant like counter flashing caulking on it so if water ever gets behind the siding it won’t get behind the flashing. Unless they just tape it with the tape they use on the seams ? I haven’t used this system yet but I’ve seen it around so I was curious about it
lol i dont know y joe lstiburek is there working on this house ….. he uses the best materials ! he came up with the perfect wall! osb is shitty! no matter what ! so the interesting thing is if joe is going to use foam board on the outside and then wrap it with a 60 mil thick membrane ! and then strap it …..maybe needs a erv or hrv in that house!
WHERE is the insulation going to be, Kevin? This looks like a great way to build a house in SoCal, where insulation needs are minimal; because fiberglass stuffing between the studs is an inefficient method. The sheer (earthquake resistance) value of that OSB comes into question. I suppose we could also triangulate the frame, before the green goes up. Then skin the green layer in shiny-side-out aluminum foil; add vertical battens, for air-gap to the outside of the foil; and air-gap to the backside of the cladding. Finalized with a fire-resistant, breathable ballast (stucco!) and we’ve achieved Joe Lstiburek’s vaunted “perfect wall.”
any of you guys ever use the sip system? a client of mine was telling me he’d like to use it. looks cool because you can us the panels as wells and for roofs…structurally! no more trusses for roofs. i was reading about it and it looks pretty neat i just wanted to ask opinions of builders (i’m an architect).