Why Does Water Pipe Make Banging Sound?

QUESTION: I have drain lines made of ABS plastic in my home, and the lines are run inside wood frame-drywall partitions. Whenever I run hot water through the line, it makes noise like someone banging on the walls with a hammer. Can you tell me how to correct it?

ANSWER: Since the noise only occurs when hot water is flowing through the drainpipe, it is probably caused by the expansion of the pipe. Apparently, the pipe is constrained by an inadequately sized opening in the top or sole plate in the wood stud wall. As the pipe expands, it rubs on the sides of the opening, creating the noise. If this is the case, open the section of wall by the pipe, and wedge a piece of polyethylene sheet or plastic milk jug in the opening. This will reduce the friction generated by the rubbing action.

How to Add Insulation to Your Attic Floor

Q: We just purchased an old house that we plan to fix and update in stages. One of our first projects is to insulate the attic floor as the existing insulation consists of a thin blanket of rock-wool. What is the best method of insulating this area?

A: What you want to do here is fill the area between the joists to the top of the joists with insulating batts. You’ll need a vapor barrier with the insulation on the side facing the floor. If you want to add more insulation, install unfaced batts or blankets across the top of the joists. This deepens the insulation layer and greatly reduced heat loss through the joists. Loose fill insulation should be installed to the weight volume printed on the bags.

Remember, the National Electric Code warns against covering light fixtures and electric motors with insulation. It requires a three-inch clearance on all sides to keep them from overheating and creating a fire hazard. Build a sheet-metal frame around such fixtures to keep the clearance.

When All Else Fails Try Using Cola on It

Q: To change a washer on a bathtub faucet, I must first remove the handle. The screw comes out with no problem, but the handle is stuck tight to the valve. How can I remove it without breaking either the handle or damaging the valve stem?

A: Usually a light tap with a wooden hammer handle or firm wiggling by hand breaks loose the faucet handle where it has become stuck by dried soap and corrosion. If this doesn’t work, try penetrating oil or even a cola drink. A few drops of cola is an old timer’s specific for a number of household and automotive problems.