Drilling Holes Plumbing Through Floor Joists

Use our joist notch and hole calculator to ensure that you get them in the right place in your joists.

Drilling holes plumbing through floor joists. Sometimes joists are notched at the end where they bear on a wall or sill. But modern living requires electrical wiring and plumbing. Wires with temperature changing pipes such as hot water pipes with aluminum ductwork. From the top and the bottom if it s a dimensional lumber joist.

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. Wires through joist brackets. Picking the right spot. If the cut outs are too large or in the wrong location the joist can be weakened and unable to support the load it was designed for.

Keep the hole at least 2 in. For a 2 10 where actual depth is 9 25 inches the maximum allowable hole diameter would be just over three inches. Holes cannot be closer than 2 to. Lean how to notch a joist for pipes and cables if you need to run pipes or cables under a floor.

The maximum allowable diameter of a hole in any solid lumber joist is one third of. Use our calculator to ensure your holes and notches are in the right position and do not affect the structural integrity of the building. Alright so those other options will not do. The diameter of holes shall not be greater than 1 3 the depth of the floor joists.

When feed wiring or pipes through existing holes make sure you avoid combining. 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. Tradespeople often need to cut notches or holes in floor and ceiling joists to run pipes ductwork or wires. If you have manufactured floor joists you will want to consult the particular manufacturer s literature.

You still need to drill a hole through your floor joist.