Is It Possible To Insulate Interior Walls With Foam Board?

Foam board insulation is a product made from polystyrene and polyurethane used to insulate interiors from exterior temperatures. It is commonly used to insulate areas of a stud wall, and the first step in installing rigid foam insulation is to cut the boards to the right size. To hang the boards with button cap nails or construction adhesive, seal the seams with tape, and replace your existing insulation.

There are two main ways to reduce thermal bridging through studs: building a double-stud wall or installing a continuous layer of rigid insulation on one side of the wall. Before installing foam board insulation, inspect the walls for any problems and check for moisture. Dry the area, remove excess debris, measure and cut the foam boards to fit the walls, drill mounting screws through the foam, or opt for an insulation adhesive to secure the panels. Fill gaps and seams with spray foam insulation.

InSoFast foam board insulation systems provide homeowners and commercial builders with cost-effective and powerful insulating materials that require little time or skill to install. Foam board insulation is a great choice for block walls, insulated floors, and vaulted ceilings. It is easy and fast to install, and it can be applied to the inside of solid walls or on the inside of wall studs between cladding and the wall.

In addition to its thermal barrier benefits, foam board is also great for air sealing, which can prevent blowing of the walls later. Some jurisdictions in the US allow exposed foam board insulation inside a building if they have passed NFPA 286 testing. Overall, foam board insulation is a cost-effective and effective method for improving thermal performance and comfort in renovations.

Can mold grow on foam board insulation?

The inflexibility of foam board insulation results in the formation of gaps and cracks in walls, which permit the passage of air and the ingress of moisture. This can give rise to a range of issues, including the growth of mold, mildew, and rot, due to the material’s lack of flexibility.

What are the negatives of foam board?

Polystyrene foam insulation board is known for its flammable and poisonous gas production after combustion, poor material strength, and instability in quality. It is prone to cracking and insulation shedding, and requires maturation before use. The recycling market has evolved significantly over the years, with foam plastic recycling becoming a top priority globally. While people enjoy the convenience of foam, they also prioritize recycling to reduce waste and protect the environment. Despite these challenges, the popularity of foam insulation boards has grown due to their potential for sustainability.

Can you put foam insulation over drywall?

Spray foam insulation is a popular choice for improving insulation in existing walls. It is installed using precise measurements to prevent excessive expansion. Excess foam can cause bubbling and cracks if installed with drywall. If drywall is not in place, it is crucial to trim excess foam for a snug fit between building materials. Spray foam insulation also improves air quality, reduces noise pollution, and reduces the need for expensive insulation materials.

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 install rigid foam insulation on interior walls?

In the past, those engaged in construction work held the view that rigid foam, which acts as a vapor retarder, should be used on the interior of buildings. Conversely, exterior foam was considered a risky material, except in the case of buildings in Florida. Subsequently, however, researchers demonstrated that this hypothesis was erroneous. The latest developments in building science and energy efficiency are now available in the weekly newsletter.

What are the cons of foam board insulation?

It is inadvisable to use insulation foam boards on walls that are uneven, as they permit the penetration of moisture, which can result in the growth of mold, mildew, and other fungi, as well as the development of odors, decay, and wood rot.

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.

Do you need an air gap with foam board insulation?

When installing foam board insulation on Masonry/Cement Block Walls, the process is similar to a stud wall, but the insulation is typically attached to furring strips, which are already attached to the block wall. Direct glue is not recommended as the insulation is more effective when there is an air gap between the wall and the board. Furring strips are typically installed using masonry nails, with a pneumatic nail gun placed on consistent centers.

The foam board is then attached to the furring strips using an appropriate nail or construction adhesive, creating a ¾” gap between the block foundation wall and the foam board, preventing moisture from coming into contact with the foam. This air trapped in the gap also adds insulative value, making the insulation more effective.

Can foam board insulation be used inside?

US jurisdictions allow exposed foam board insulation in buildings if they pass NFPA 286 testing. The International Building Code (IBC) 2015 exemption applies to residential and commercial buildings. Halo’s Interra Plus has passed this testing and can be left uncovered on the interior, provided the boards are not more than 2. 28 inches wide. However, XPS boards are susceptible to UV ray exposure, causing their physical and insulative properties to weaken. To protect them, they must be covered within 60 days.

Does foam board need a vapor barrier?

The necessity of a vapor barrier in foam rigid insulation depends on the specific situation. In colder climates, an extra vapour barrier is often recommended to prevent moisture from penetrating the insulation layer, which can lead to condensation and damage. In high humidity areas like bathrooms, laundry rooms, or kitchens, a vapour barrier is typically recommended to prevent moisture buildup and damage.

This is especially important for PIR foam insulation, as the foam material can absorb moisture and potentially degrade over time, especially at joints or gaps where moisture can infiltrate. In summary, the necessity of a vapor barrier depends on the specific situation and the specific needs of the insulation.

Is foam board insulation good for walls?

Modern foam board insulation is not your father’s rigid insulation. Modern foam boards can control vapor and moisture flow, keep wall cavities dry, and be customized to suit various building applications. EPS, or Extruded Polystyrene, is the least expensive foam board product and has a minimal amount of embodied carbon compared to XPS products. By adjusting the combination of laminate and foam core, these panels can be tailored to suit almost any building application.