To Coat or not to Coat?
One of the many inquiries customers have regarding spray foam insulation is if they need to apply a coating after a foam application. The answer depends on the type of project the user has been working on. Is the foam going to be exposed to the outside elements? Will there be human habitation in the area around the foam? If spray foam is going to be exposed without some type of fire barrier such as dry wall or sheet rock, then coating will be required. In most cases if you spray foam a wall and add dry wall over the foam, you do not need to use a coating. The other instance a coating should be used is if the foam is going to be exposed outside.
There are many different types of coating that can be applied to spray foam. For a roof application, you should use an acrylic coating. Harmful UV rays, as well as severe weather conditions such as hail and heavy rain can cause foam to deteriorate over time. For example, a foam roof left without an acrylic coating will begin to deteriorate and turn to dust. Adding this type of coating prevents this issue from happening. Once the foam has cured you should begin applying coating within a couple hours to ensure the foam is protected.
Fire Brand Coatings
Spray foam that is going to have human habitation needs to have a fire ignition barrier. This basically means that in the event of a fire, the foam will resist the fire longer than it would without coating. A fire brand coating comes in the form of a liquid and is a single component coating that contains fire retardants to reduce the spread of flames in the event of a fire. Not only does it provide fire resistant properties but it also serves as a great waterproof barrier as well. This is advantageous in the event of a flood. The great thing about this coating is that it can be applied to many different types of insulation and substrates. Moreover, these coatings are easily applied with the use of a brush, roller or airless spray. The below picture illustrates a structure with a fire brand coating and one without a coating.
How to apply it?
The best time to apply coating to foam insulation is usually around an hour or two after a spray foam application. You could probably wait a little longer depending on the type of spray foam project. Roof applications should be coated within the above time frame to protect the foam from the sun and moisture. The surface area must be completely dry, clean and cleared of any debris. This will ensure the coating adheres to the surface properly. If you need more information regarding the different types of coatings or have questions about your next project, please don’t hesitate to contact us.