Insulating a Cathedral Ceiling with Foam it Green

Treat your cathedral ceiling just like a wall, with a different angle. Foam it Green spray foam bonds overhead. Check out the Overhead Project video to get some tips and techniques to make this project easier.

Using Foam it Green spray foam insulation in your cathedral ceiling can give you much lower utility bills and reduced sound transfer. Here’s how to do your cathedral ceiling with Foam it Green spray foam insulation.

Full Fill

If you want, tape off the studs with painter’s tape so you can easily pull off the tape later and have clean studs ready for sheetrock.

Use a drop cloth on the floor to protect areas from any falling “snow” (foam particles)

Spray on Foam it Green so it rises to an inch or two at a time. Move to the next cavity and repeat. Typically for spraying overhead, you’ll want to use just the normal cone nozzle.

Once all the stud bays are full with the initial coat, make sure it’s cured.

If they have, repeat the process, building upon the previous inch an inch or two at a time.

For the final coat, move faster so you just get a quick coat.

Full out, you can spray a 602 in 30-40 minutes, so while this may sound slow, it’s in fact the fastest and easiest way to seal and insulate a cathedral ceiling.

If you overfill, just use a serrated knife to shave back the spots so you can put up drywall.

Your ceiling now has a seamless air barrier that saves massive amounts of energy, along with a high r-value. Your ceiling also now greatly reduces sound transfer and provides a large deterrent to pests. Your family also enjoys a much better air quality.

Partial Fill

Some people can use just 1 inch of Foam it Green closed cell spray foam insulation and others need more.

It depends on the project and where you live.

According to building scientists, the general rule to follow is:

If you heat during the winter, you need 50% (or more) of the total R-value of an enclosed cathedral ceiling’s insulation in Foam it Green closed cell spray foam.

Here’s why. The dew point happens when hot air meets cold air. The cold air cannot hold the moisture in the warm air, so it turns to water and drops from the air, creating condensation.

If this condensation happens in Foam it Green closed cell spray foam, the condensation has nowhere to go. If the dew point happens in the open cell foam or fiberglass, you’ll have condensation between the foam and the other insulation.

You just need to make sure you accommodate for the dew point so you don’t have moisture issues.

2×10 Rafters (cathedral ceiling) = 9.5 inches of space
3.5 inches Foam it Green Closed Cell = R-24.5, 6 inches fiberglass = R-21. The Dew Point will be in Foam it Green and thus minimize moisture issues.

If you want, tape off the studs with painters tape so you can easily pull off the tape later and have clean studs ready for sheetrock.

Use a drop cloth on the floor to protect areas from any falling “snow” (foam particles)

Spray on Foam it Green so it rises to an inch or two in each cavity. Move to the next cavity and repeat. Typically for filling stud bays, the fan spray tips help broaden the spray so the foam goes on fast and about the width of the cavity.

Once all the stud bays are full with 1 inch, make sure it’s cured.

If they have, repeat the process, building upon the previous inch an inch at a time.

For the final coat, move faster so you just get a quick coat.

Full out, you can spray a 602 in 30-40 minutes, so while this may sound slow, it’s in fact a very quick way to do walls.

Your cathedral ceiling now has a seamless air barrier that saves massive amounts of energy, along with a high r-value. Your ceiling also stops sound transfer and provide a large deterrent to pests. Your family also enjoys a much better air quality.