Site Map

No obligation free estimate 416.782.1900Available 24/7

Get A Quote Now

* Required fields

Limited Time Offer

Request a FREE NO-Obligation Estimate and Receive a 10% OFF Discount Today. Call Now 416.782.1900

What Happen If Spray Foam Insulation Gets Wet?

When it comes to insulating your home, you are considering more than just heat in summer and cold in winter.  While temperature regulation definitely affects your energy bill, insulation is also meant to be a barrier against moisture. Moisture not only threatens the life and integrity of the wood, it can also lead to things like mold and mildew, which can threaten the health of your family.  You have likely rad about the greater energy efficiency of spray foam insulation, its superior seal, and the fact that it can actually strengthen your walls.  However, you may have questions about how spray foam reacts with moisture.  In other words, what happens if spray foam insulation gets wet?


There are some myths out there about spray foam and water that we’d like to clear up in this post by giving you some facts to answer this question.  First, what happens when the foam itself gets wet?  Will it still dry properly?  Open cell spray foam insulation will still dry completely after getting wet.  If the amount of water is extensive, the shape may be affected, but it will still dry completely, and then any shape imperfections can be filled in easily.  If spray foam polyurethane gets wet after a couple of minutes, it will still dry effectively with no shape problems because it forms a “skin” that is water resistant.  Single component foam is more affected than polyurethane but can still dry; it just may need some shape correction.  In addition, because spray foam is not a “food” for mold, there is little danger of mold becoming a problem even if it gets wet.  Closed cell foams also do not absorb water, which is very beneficial in flooding zones.  In fact, because it is water resistant, it is often used as an effective repair for leaky basements.


What about wet surfaces?  Can spray foam insulation be used on surfaces that get wet?  Will its water resistance trap water and cause mold or decay?  This is one of the myths about spray foam.  Spray foam has been used and installed in various places where water is a consideration, such as the underside of roof decks, for decades, and there is no record of it causing deterioration to the wood, even when the wood gets wet.  It seals any cracks or crevices and repels the water, protecting the wood more effectively.  In addition, in colder climates, it helps to keep the rook deck cold, thereby preventing ice damming. In warmer climates, potential customers have sometimes been concerned about humidity and vapor as potential water problems.  Actually, the composition of closed cell spray foam allows a controlled flow of moisture vapor as it separates the inside and outside temperatures, which controls condensation more effectively.  And even if wood is wet when spray foam insulation is applied, repeated tests indicate that while the lumber may dry more slowly, it will dry, and the seal will still be in effect.  So while it is best practice to spray the foam onto a dry surface, even a damp surface can still be protected.


In short, water does not have to be a concern with spray foam insulation, whether the issue is a spray foam that gets damp after installation or a spray foam that is installed on a portion of the home that may have some dampness.  If you still have questions about what happens if spray foam insulation gets wet, contact Airseal, and we’ll be happy to address all of your concerns and inquiries about spray foam insulation.

Insulation is for more than just keeping your home warm in the winter and cool int he summer. It also helps act as a barrier against moisture. Moisture in your home can lead to the growth of mold and other harmful air pollutants. These things can adversely affect the health of your family. Whether you’re looking to get better energy efficiency or prevent mold from growing in your space, you’ve probably looked into spray foam insulation. If you have questions about how it reacts to moisture, you’ve come to the right place. Read on to find out what happens if spray foam insulation gets wet.



There are many questions you may have about spray foam insulation and water. What happens to the foam itself when it gets wet? Will it dry? The answers to these questions depends in part on what type of insulation you have. Spray foam insulation comes in open cell and closed cell varieties. The two types of foam react very differently to moisture and other hazards, so it’s important to take into account the area your home is located in when choosing the type of insulation you want to use in your home.

Open Cell insulation


Open cell insulation will dry completely after getting wet, but if the amount of water is excessive, the foam can change shape. Changes in shape can lead to gaps where air and more water can get through into your home. You can always fix the shape and fill in any gaps later on, but if moisture is a constant problem, this type of maintenance may be too cumbersome.

Single component spray foam insulation is more likely to be affected by water than mixed foams. Also, it’s important to note that mold cannot eat foam insulation so even if it does get wet, it will not mold. Wood and other components around the insulation may mold though.


Closed Cell Insulation


Closed cell foams do not absorb water, making them better for use in moist environments or flood zones. The insulation is water resistant and is often used as a repair mechanism for leaky basements. Wet surfaces are also a candidate for closed cell spray foam insulation. The underside of roof decks are a great place for this type of insulation. It can seal cracks or crevices and repel water without being effected by excessive water itself.

In cold environments, closed cell insulation can help keep a surface cold to prevent ice dams. In hot areas, it can be used to keep a surface warm to prevent humidity from gathering. In general, you should apply the spray foam to a dry surface to begin, but closed cell varieties can be applied to damp surfaces if needed.

In conclusion, water should not be a concern when choosing spray foam insulation. In fact, spray foam insulation can be a great remedy for areas of the home that get wet or have water infiltration on a regular basis.  Talk to your Local Spray Foam Contractors to find out how sprayfoam can help protect your home from moisture.