I Need to Put Insulation in Walls: Can I Use Spray Foam so I Don't Have to Rip Up Walls?

Prepping the Walls

• Remove everything from the wall you want to insulate. If you plan on insulating four walls of one room, start with the wall furthest from the entryway. Remove fixtures that may fall and break such as picture frames or delicate ornaments. Use a stud finder to locate each stud. You’ll want to avoid the studs and concentrate only on free empty space, so mark the studs with an X for reference. Next, use a tape measure to measure out insertion points along the wall, about 1 foot up from the baseboards and spaced apart about 3 feet or so.

Drilling

• Use a carpenter’s pencil to mark each location with a small circle, well away from the studs in the wall. Outfit your electric drill with a ½-inch bit and drill holes through each circle you marked. Once the holes are ready, spread a dropcloth across the floor flush against the baseboards to catch any mess that may leak out. Gloves and eye protection are highly recommended. Now it’s time to add the insulation.

Adding Insulation

• Insert the nozzle tip of the spray foam container’s tip into the first hole and add a first run of foam. Spray it run for about a minute before removing the nozzle and tapping on the upper part of the wall. Listen to the sound the tapping makes. If it sounds hollow, reinsert the nozzle and add more foam; if the tapping sounds more like a thud, the wall section is full and you should remove the nozzle and move on the next hole.

Finishing the Job

• Repeat the procedure for every hole you drilled. Keep watch as you go. If the next hole ahead of the one where you’re working starts to leak foam, the wall is getting filled to capacity. Once all the holes in the wall have been addressed, scrape away excess foam that oozed out and refill each hole with drywall patch to cover up the holes. If the patch you used isn’t the same color as your wall, paint the wall to hide evidence of drilling.