Can I Leave Foam Board Insulation Exposed on Exterior Walls? When exposed outdoors, foam board insulation can see damage from the Sun's ultraviolet (UV) rays. Rays reflected from a surface, like a nearby window, can be particularly damaging to foam boards.
To answer your question, yes foam does lose its insulation value when it gets wet, but not 100% of it. And no, it will not dry out.
The lifespan of PVC foam board can vary depending on the quality of the material and the environment it is exposed to. High-quality PVC foam board that is properly installed or maintained can last up to 20 years or more in construction applications and up to 5 years or more in outdoor signage applications.
If you need a foam that you can leave in place, then you need foam that has been manufactured specifically to be used outdoors, like Calipore foam from F.C. Hancox. The best outdoor foam will be waterproof. The cells of waterproof foam are large, allowing for air to easily pass through, drying any moisture within.
Styrene foam is not designed to withstand extended outdoor conditions. One reason foam should be sealed is because it is highly sensitive to UV rays. The plastic material will break down into a discolored powdery substance or become brittle upon long-term exposure.
Foam Board Insulation: Can be left exposed for 30-60 days but should be covered to protect from UV rays and physical damage. Fiberglass Insulation: Should be covered as soon as possible to avoid health and safety risks.
In conclusion, PVC foam board is an excellent material for outdoor applications.
As an inert product, spray foam does not break down. However, over time, all types of insulation experience decreased R-value, the unit of measurement that indicates how well insulation restricts conductive heat flow.
Another popular question is whether foam insulation is waterproof. Closed cell spray foam is water-resistant, meaning it won't absorb moisture, and it can help protect your home from water damage by creating a barrier. However, it's essential to understand that no insulation material is completely waterproof.
Every type of insulation will react differently when it gets wet. Fiberglass insulation will lose its effectiveness as air is displaced by water, causing it to conduct heat instead of insulating your home. Cellulose will begin degrade if it's not dried quickly, and it can start to grow mold.
Open-cell spray foam is more porous than closed-cell foam, so it may absorb water if it gets wet. This can lead to decreased R-value and, over time, the potential development of mold or mildew if the moisture is not properly addressed.
Under direct sunlight, spray foam will degrade at a rate of 1/16th inch per year.
The longer foam material has expired, the riskier it can get. It can be like putting after-gas in your race car.
Unfaced insulation is a plain batt or roll of fiberglass insulation with no facing. It is Class A fire-rated, which means it can be left exposed, or used in specific fire-rated assemblies. Unfaced insulation can also be used with vapor retarders such as polyethylene or polypropylene (depending on local code).
Open-cell foam is more open and less dense, but it is not great for outside because it gets damaged by moisture and UV. Closed-cell foam is denser and stiffer, and it fights moisture and air better, making it good for outside use.
In conclusion, while PVC foam boards have a certain level of water resistance, they are not completely waterproof. Prolonged exposure to water or excessive moisture can cause them to swell or warp.
Quick dry foam is a highly resilient and durable material and is recommended if you want to leave your outdoor furniture outside exposed to the elements all year round.
Cons of a Foamboard
Foamboards can get discolored, disintegrated or warped if left under the sun or rain. It can be used for a short outdoor event and not as a permanent outdoor display. Also keep it away from your bathroom or kitchen as steam can create moisture, affecting the foamboard.
Spray Foam Cannot Be Exposed Without A Protective Coating.
Sun, rain, snow, or sleet can all cause damage to spray foam insulation. Spray foam in exterior applications, such as roofing, is exposed to all these elements. Roof foams are most commonly coated with waterproof coatings to protect the foam from damage.
The surface of polystyrene foam is usually smooth, but not absolutely smooth and gapless. Its surface energy is relatively low, which means that it has a weak adsorption capacity for moisture and other substances. However, this does not mean that mold cannot attach and grow at all.
It is also used to make crafts and sculptures. Styrofoam is an excellent material because it is lightweight and easy to cut and shape. However, it is not waterproof and can be damaged by water. This is why it is crucial to waterproof Styrofoam if you want to protect it from water damage.
Rigid polyurethane and polyisocyanurate foams will, when ignited, burn rapidly and produce intense heat, dense smoke and gases which are irritating, flammable and/or toxic. As with other organic materials the most significant gas is usually carbon monoxide.
New research published by scientists at the Woods Hole Oceanographic Institution shows that polystyrene, one of the world's most ubiquitous plastics, may degrade in decades or centuries when exposed to sunlight, rather than thousands of years as previously thought.