Drilling Holes Plumbing Through Floor Joists

How to drill a hole through the side of a floor joist.

Drilling holes plumbing through floor joists.

In a perfect world floor joists are left whole to provide the greatest support. There are regulations in the uk you must follow in new build insta. Drilling floor joists to run plumbing wiring or ducts can be tricky. Use our joist notch and hole calculator to ensure that you get them in the right place in your joists.

The maximum allowable diameter of a hole in any solid lumber joist is one third of. Notches in the top or bottom of joists shall not exceed one sixth the depth and shall not be located in the middle third of the span. But modern living requires electrical wiring and plumbing. Holes bored in joists shall not be within 2 inches 51 mm of the top or bottom of the joist and the diameter of any such hole shall not exceed one third the depth of the joist.

I noticed that quite a few people have a common concern that drilling holes in joists will make them weaker. Lean how to notch a joist for pipes and cables if you need to run pipes or cables under a floor. I hate putting waste pipe through joists for the reasons. Engineered floor joists can be drilled only according to their manufacturer s guidelines the code specifies the maximum size of the holes you can drill or the notches you can cut where you can and can t place them and how far apart they can be spaced.

Keep the hole at least 2 in. There are very specific locations and sizes in the code telling you what is allowed. Holes cannot be closer than 2 to the bottom or top of a joist or to another hole or notch in the joist drilling floor joists. You often require drilling holes in ceiling joists to pass any electrical or plumbing runs through the ceiling or floor.

Where and how to drill joists for electrical cables or plumbing runs depends on what type of floor framing you have. Even if you are going to drill a hole through the joist one of the problems you are going to get is threading the pipe through and you don t want any joints in the ceiling space. Use our calculator to ensure your holes and notches are in the right position and do not affect the structural integrity of the building. 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.

From the top and the bottom if it s a dimensional lumber joist.