Sounds of Water Running Through Pipes Behind Walls

December 16th 2009
Sounds of Water Running Through Pipes Behind Walls

Q.  We recently purchased a home that is about 15-years -old and we can hear water running through the pipes inside the walls every time somebody drains water in the upstairs bathrooms. Is it too late to insulate these pipes?

A. It is a good idea to insulate all walls inside the home on all levels using R12 or R14 glass fibre batting. Houses that do not have insulation around pipes on the inside walls can still be done with little work. No vapour barrier is required as you are doing it for sound only, however I do recommend using an insulation that resists moisture such as Roxul's Comfort Batt brand. This is a rock wool soundproofing insulation designed specifically for use in interior walls. This will give a tremendous sound deadening effect to all rooms not only water sounds through the pipes but as well as privacy between rooms.

To sound proof noisy ABS plumbing pipes, locate the wall cavity encasing the noisy pipes. 
Using a stud finder, locate studs on either side of noisy pipes:

- Once you have located studs measure approximately 3/4" to 1" from cavity side to identify centre of studs, make a mark.
- Measure up from floor 12" and down from the ceiling 12" and make a mark.
- Using a 4' level and holding it plumb on the stud centre marks draw line up the stud to dissect 12" mark from ceiling and down to dissect bottom mark from the floor.
- Join all marks forming a rectangle on the wall this identifies the stud opening housing your noisy plumbing.
- With a drywall knife and using a straight edge cut along all marks. Apply pressure as you are cutting through 1/2" of gypsum board. (if plaster, a drywall saw may be required.) Caution: Any electrical power duplexes or switches must be shut off.)
- Remove piece of gypsum board revealing pipes behind wall. Using R12 or R14 fill entire cavity with the insulation (split bats in half to go around noisy pipes).
- Replace piece of drywall (cutout) and nail to studs, sand area along painted side of patch and drywall tape and fill. Drywall filler should extend 6" to 10" either side of seam, this will feather out edge before priming and painting.

It's Just That Easy
Shell Busey