Temperature and Spray Foam InsulationMark Munns
December 6, 2011 — 4,944 views
Before spray foam insulation (SFI) has been applied and had a chance to cure, it likes to be in a comfortable environment. Think of it as Granny Polyurethane, she needs tender care and just the right environment to be at her best. Everything needs to be just so, and when the setting is right then Granny is happy and more willing to offer protection against the harsh outside world.
SFI has the best adhesion and most ideal curing process when it is applied in 60-80F degrees (15-26C). If the season is right and the ambient temperature is already hovering in that range, then there is nothing to worry about. On the other hand, if installation is occurring in an environment that is below 60F (15C) then heating the space will be necessary. Applying spray foam insulation in cold weather is a tricky business. If the surface is cold but the space underneath the surface is heated (like an attic), there may be condensation. Using SFI in a cold space means the flow will be slower and the curing time will be longer.
To really be sure if the area to be sprayed is damp or too cold, do a test patch. If the test patch properly adheres, then carry on. But, and this is a big but, apply just a thin layer of spray foam to bring the ambient temperature up to an ideal level. In essence, by spraying this thin preliminary layer of foam, you are creating an environment that is the perfect temperature for spray foam to cure. Once the first thin layer has cured, go over the entire area again to achieve the desired thickness for the intended R-value.
When the intended space to be sprayed is too hot, then there are further problems. First of all, heat causes higher rates of pressure in the canisters which in turn means a faster flow rate. A faster flow rate can mean less control over spray and uneven layers of foam. When the environment is too hot, the foam will cure too fast and cause a whole host of problems. If the curing process occurs to quickly then the foam has no chance to develop a bond with the surface before it becomes hard. There is also the risk of the foam curing before it has reached its full rise; this results in a lower R-value, and in turn a loss of investment dollars.
Caring for and storing the polyurethane tanks is just as important as applying the SFI in the right temperature. If the storage environment is too cold, the liquid components in the tanks will separate. When used, the foam will be darker and have a crusty surface. Ideally, when SFI is being applied it should be light green and evenly textured not glassy. If you go to use the SFI and find the area below 60F (15C), simply warm the tanks with water and shake them up very well to reverse any separation in the liquids. If the tanks get too warm, do the same thing. Shake the tanks up and cool them down with water. Check the flow with the gun as well, for both scenarios. Keep in mind, if the tanks are in a place that reaches temperatures above 120F (48C), the pressure might pop the burst plug, losing the pressure in the tanks.
Storing spray foam tanks properly will protect your investment, and keep the product in a good ready-to-use state at all times. The tanks should always be upright to prevent a loss of foam pressure. Keep the area between 60F and 80F (15-26C), but most importantly: use the gun at least once a week. If you live in a humid climate, use extra petroleum jelly on the gun and if you can, use it more often than once a week. Forgetting to use the spray gun regularly and often will mean build up in the components, resulting in an uneven spray or blockage. Simply spray a couple of times into a garbage can as often as possible to avoid having to get a new gun.
It seems a little finicky, doesn't it? Temperature ranges, patch tests, proper storage, it's just a lot for something so unimportant. If this is how you really feel, then there is a lot more to learn about the benefits of spray foam insulation because it is very very important to the health and efficiency of every home. Just in terms of heating and cooling, consider the following comparison: regular pink fiberglass batt insulation has a maximum R-value of 4.3, while closed cell polyurethane spray foam has a maximum R-value of 6.5. More importantly, closed cell polyurethane spray foam seals out air. According to the US Department of Energy, that can translate into 40% savings in heating and cooling costs. Savings like that are well worth caring for spray foam tanks properly and applying the insulation in the correct conditions. Besides, once the SFI is in place it never needs to be maintained or replaced again.
Mark Munns is a representative of Spray Foam Direct. Featuring quick and easy do-it-yourself expanding foam insulation which will save you money and energy. For more information about our product line, visit us online today!