If you decide to install the insulation yourself – as many homeowners do to save even more money – you must follow some basic instructions to avoid making mistakes.
Here are seven common spray foam insulation mistakes to avoid:
1. Spraying Cold Foam
When the spray foam insulation kit is not sufficiently warmed up, the spray that comes out will be too cold. Cold foam leads to a reduction in hardener, so it comes out softer, spongier. When that happens, you lose R value and the full benefit of the insulation.
To avoid spraying cold foam, you need to warm up the kit using a small heater with a thermostat or place it in direct sunlight. Foam Kit Solutions recommends making a little tent around the cylinder and heater with cardboard or some other material to facilitate the process. Caution: You want the foam cylinder slightly warm to warm to the touch, not hot.
Once it feels warm, grab the collar on the cylinder and rock it back and forth for about half a minute. Often the chemical in the middle of the cylinder remains cold, despite the fact that the outside feels warm. Shaking the cylinder helps re-distribute the chemical.
After shaking the cylinder, feel it again. If it now feels cool to the touch, that’s a sign you’ll need to warm it up a little longer. If not, then you’re good to go.
Foam Kit Solutions provides you with a special temperature warning nozzle to ensure you’re spraying foam at the optimal temperature each time. It works by changing from clear to blue when the temperature is too cold.
2. Spraying Hot Foam
Again, you want the cylinder to feel warm to the touch. If the cylinder gets too, the foam will become crusty and flaky. This results in a loss of R value.
3. Spraying With a Clogged Nozzle
If the tip of the nozzle starts to clog up, replace it with another. Otherwise, the spray pattern will be uneven or irregular.
You want a nice, even spray pattern. You can see this when you start spraying with a new tip. You’ll notice, however, the spray pattern gradually declines as you continue spraying.
That’s because the foam is always sticky and tends to build up on the tip of the nozzle. When you see that happening, simply rub the tip against a 2×4 or joist to see if that corrects the spray pattern. If not, put on a new nozzle.
The Kit Instructions tell you that if you stop spraying for 30 seconds, the nozzle tip will clog and become useless. Foam Kit Solutions suggests not waiting beyond 20 seconds.
Since a nozzle tip is cleanable, you can clean it for re-use. First, you’ll need to pop the nozzle off as soon as you’re done letting off the trigger and immediately stick it in a can with a couple inches of acetone.
Hold on to the nozzle’s clip as you submerge the nozzle in the acetone, moving it back and forth several times to allow the acetone to rinse through it. A good rinsing removes the foam, enabling you to re-use the nozzle. But fail to do this immediately after taking it off the gun, you might as well toss the nozzle.
TIP: Suppose you’re using a ladder while applying spray foam insulation and need to stop every so often to move it. Since you have 20-30 seconds at most before the nozzle gums up, give a shot of foam to the stud every 20 seconds to buy a little time until you get the ladder re-positioned.
4. Failing to Heed the Temperature
Whether you’re spraying in an attic or a basement, you want the temperature of the surface (substrate) that’s to be sprayed to be within the manufacturer’s specified range. You shouldn’t spray if the substrate is below 50º F because when the temperature goes that low there could be moisture on it. You must have a dry surface for the spray to stick.
Spraying in a hot attic causes the foam to cure too fast. It then becomes hard and crusty and ends up cracking and shrinking away from the studs.
If an attic is either too cold or too hot, Foam Kit Solutions offers this tip: Spray the attic roof with a flash coat. That is, spray it fast and with a very light coating. This creates an exothermic barrier which brings the temperature to a more optimum level. You can then spray over that with a normal spray coat.
5. Spraying Too Fast
Spray very slowly and keep moving away from what you sprayed. Spraying too fast means you’re only going to put down about ½ inch of foam. You’ll have to go back over it later with another coat.
6. Over Spraying
Keep moving very slowly away from the area you’re spraying. Don’t stay in the same spot for too long because if you spray a spot and immediately spray over it seconds later, you’ll end up doing what’s called “pounding it down.”
This means you’re not giving the spray foam a chance to grow. You’re throwing fresh spray foam right over the foam you just sprayed and end up losing half of the foam volume doing that.
When you spray an area and you want to add another coat of foam, come back in 45 seconds to a minute later.
7. Not Ordering Enough Spray Foam
Sometimes homeowners don’t order enough spray foam. For instance, if you want to spray an area that’s 1800 square feet, you might think that ordering 3 Spray Foam Insulation kits (each spraying 600 sq. ft.) will be sufficient. But it’s actually better to order an extra kit because you lose a little bit of yield during the spray process. In that case, you’ll fall short of the necessary amount of foam.
Besides ensuring you have enough spray foam to complete the job adequately, Foam Kit Solutions says if you order an extra kit you can save on shipping costs (four kits ship for the same cost as one).
A Final Word . . .
Each spray foam insulation kit comes with complete instructions. To ensure they are read and fully understood, Foam Kit Solutions asks homeowners to call back for a complete review of the instructions. This helps them avoid these and other common mistakes, and enables them to apply foam insulation safely and correctly.