Cutting Floor Joists For Plumbing

Codes don t directly address how many holes and notches you can cut in a joist.

Cutting floor joists for plumbing.

As a remodeling contractor and carpenter one common structural framing issue i see alot of in bathroom remodeling jobs are floor joists that were cut drilled notched or need to be cut out to accommodate plumbing pipes and drains. 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. If your home is more than 20 years old your floor joists are most likely solid wood 2x8s 2x10s or 2x12s. When it s time to remodel it s often also time to reroute plumbing or replace subflooring that may have become rotted or cracked.

One rule of thumb is to provide twice the distance between holes as the diameter. The maximum allowable diameter of a hole in any solid lumber joist is one third of. Of walls and rim joists. The worst thing is when new homes or poor remodeling jobs end up with joists that are cut to fit the pipes and no repairs are ever made.

Tradespeople often need to cut notches or holes in floor and ceiling joists to run pipes ductwork or wires. I ve also sistered on steel flat plate when i wasn t able to nail on a long enough replacement joist for example existing plumbing or electrical wires prevent you from getting a full. I jacked up straightened out the floor before gluing nailing and carriage bolting the new joist to the cut joist. Roger goes over the best practices and rules for notching and drilling holes in joists while filming our bathroom series.

Where and how to drill joists for electrical cables or plumbing runs depends on what type of floor framing you have. Sometimes joists are notched at the end where they bear on a wall or sill. Holes anywhere in the web area of engineered i joists except within 6 in. One fix i did was to sister on new joists.

Structural floor joist repairs. It s important to calculate the siz. How to cut the subfloor to access the floor joists for plumbing. The notching and boring rules of thumb for solid lumber are shown in fig.