Insulating around a bathtub prevents everything from drafts to mold. While most insulation is completed during tub installation, older homes may be lacking in modern insulation amounts. Many states now require R-19 insulation in bathroom exterior walls and R-30 in the ceiling. This higher insulation requirement serves to hold warm air in the bathroom more efficiently, ideally making it cheaper to heat the room. Additionally, some homeowners are also insulating around the inner walls of the bathtub to help the tub retain its heat longer. Insulation upgrades are best done during a remodel, because they require removal of the drywall and tile.
Things You'll Need
- Stud finder
- Vapor barrier
- Moisture-proof backer board
- Foam insulation
- Drywall nails
Determine the current insulation rating for your bathroom walls by reviewing your home’s building plans. If your home was built before 1990, assume it could use an insulation upgrade.
Locate the studs in the wall with a stud finder and mark them with a pencil.
Tear away the drywall layer using a hammer. Be sure to wear a mask to prevent inhaling any dust. Remove the entire drywall, as it will be replaced.
Remove any waterproofing such as backer boards and roofing felt.
Pull out any old insulation and fill in the spaces with new R-19 rated insulation.
Place a vapor barrier against the wall and secure it to the studs with a staple gun.
Cover the walls with a fresh moisture-proof backer board secured with 4-inch drywall nails and seal off the places where the tub meets the backer board with a bead of silicone.
Remove the caulking around the bathtub edges. Tear away the tile and drywall.
Remove any bolts securing the tub in place with a wrench. Move the tub out so that the back panel is accessible.
Spray all the cavities inside the tub with spray foam insulation. A rating of at least R-7 is recommended for bathtubs.
Slide the tub back into position and re-secure it to the studs.
Cover the space between the studs and the tub with a vapor barrier to prevent any moisture from touching the wood. Cover the walls with a fresh moisture-proof backer board secured with 4-inch drywall nails and seal off the places where the tub meets the backer board with a bead of silicone. If desired, replace the tiles around the bathtub with fresh tiles.