Running Pipes Through Floor Joists

Running drainpipe through joists calls for meticulous work.

Running pipes through floor joists.

One contractor says he will run the pipe to the waste through the joists. At this time the joists are not exposed so i am going on the assumption that they are 2 10 s. Can my husband drill through the joists to run the new pipe or will that weaken them. If you are going out through a wall at the end of the run consider feeding the pipe in from the outside avoiding joins under the floor.

Each joist must have a separate notch or hole and each hole should be about 1 4 inch larger. Where the toilet is now will be the sink and vanity. Rose sagady via email none. Secure the line to the joists using clamps image 2.

Running drainpipes through floor joists is more complicated than running them parallel to the joists. Engineered floor joists can be drilled only. A plumber says never cut through the joists and a new waste pipe will need to be installed. The international building code irc has specific guidelines with illustrations for drilling and notching solid lumber floor joists.

You can drill the holes anywhere along the length of the joist first photo. The holes will have to follow a straight line that goes across the floor and has to either go up or go down so the pipe has a slope. The rim joist fig. This is an engineering question and has to do with the structural loading of the floor above and the reduced load ratings on those joists.

Or find a better way to run that pipe at 2 diameter that seems to be a venting pipe. Pull the lines up through the holes drilled in the sub floor image 1 and then run the other end to the area where the water will be coming into the home. The slope should be about 1 4 for each foot of pipe. The holes must follow a straight line across the floor and must ascend or descend so the pipe will be sloped 1 4 inch per foot.

When you run your pipes through a joist you will have to be careful with your work. Ken may 10 17 at 2 23. If joists are 16 inches on center and pipes run across them at a right angle holes should differ in height by about 3 8 inch. You are going to need to add joists to accommodate the load of the second floor.

The hole cannot be larger than one third the depth of the joist so the maximum hole size for a 2 12 joist actual size 1 1 2 x 11 1 4 in is 3 3 4 in. Do your best to separate the hot and cold lines to minimize heat transfer. Step 3 understand the joist slopes. B the framing member that runs around the perimeter of your house and that the floor joists butt into often gets riddled with large holes this space is the logical exit point for dryer and furnace vents big electrical service wires and fireplace fresh air intakes.

Be sure to leave extra pipe on both ends of the run. Step 4 cut the holes.