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Spray Foam Covered Uncovered Which Is Best?

Spray foam does a great job of keeping the home nice and warm, but as with anything new that you bring into your house it’s natural to have anxieties about exposure to it. After all, the whole point of the product is to create a safe and comfortable environment for you and your loved ones. If you’re having spray foam insulation put into your walls, then you have a fairly clear idea that you will have at least a dry wall between you and any potential hazards. However, if you’re having it put into your loft you’re suddenly faced with a choice as to whether to cover it or not. The question is, Spray Foam Covered Uncovered: Which Is Best?

Covering spray foam insulation vs leaving it uncovered (which is best?)

When it comes to deciding whether to cover insulation or not, the good news is that you don’t have to worry about toxic fumes or ‘evil chemicals’ seeping through the walls. In fact, there are typically only three factors which you need to consider: thermal factors, vapour factors and ignition barriers. Vapour barriers aren’t really anything to worry about, and thermal and ignition barriers follow a similar concept, but in practice are quite different.

Vapour Barrier:

A vapour barrier is there to keep the moisture out and stop damp setting in to any of the structural materials. When it comes to spray foam insulation, vapour barriers are pretty simple: you don’t need one. Spray foam insulation is water proof so no water will be getting in or out, with or without a barrier. Ignition barrier: An ignition barrier is a barrier designed to prevent an insulation from catching fire. Ignition barriers are in principal usually required, but because of where spray foam is typically used, you’ll most likely have an ignition barrier without having to worrying too much about it. Things like dry wall and wooden panels serve as perfectly good ignition barriers. For dry wall you only need about 9 mm, and for wood you only need a thickness of about 6 mm for your arrangement to be both safe and legal (depending on where you live). This means that almost anywhere you’ll put spray foam insulation, you’ll likely be protected by the walls or floor boards which are already in place. The only exception to this is if you’ve not already got a wooden board floor in the roof. Thermal barriers: Unfortunately, this is where things get a bit more complicated. An ignition barrier stops fire getting in and setting the spray foam on fire. However, a thermal barrier is a barrier which is designed to stop heat from fire from penetrating the spray foam and causing damage. Even if the fire cannot get in easily, if spray foam insulation can still heat up and burn. Although Icynene foam is much less flammable than the highly combustible polyurethane, and is in fact a fire retardant, it is still vulnerable to high levels of heat. It depends on where you live, but many places, including the UK has strict legal requirements when it comes to thermally protecting insulation and you’ll likely need a good centimetre of something thermally resistant to make your spray foam insulation completely safe.

When it comes to the question of which is better: covered or uncovered, one must conclude that without a doubt it is better to cover spray foam insulation. However, because of certain strengths of spray from insulation, particularly icynene insulation, it will likely be much quicker and cheaper than you imagine to get your loft into the state it needs to be in to be completely safe!