Cutting Floor Joists For Plumbing

How to cut the subfloor to access the floor joists for plumbing.

Cutting floor joists for plumbing.

Codes don t directly address how many holes and notches you can cut in a joist. The maximum allowable diameter of a hole in any solid lumber joist is one third of. 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. One rule of thumb is to provide twice the distance between holes as the diameter.

It s important to calculate the siz. One fix i did was to sister on new joists. 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. If your home is more than 20 years old your floor joists are most likely solid wood 2x8s 2x10s or 2x12s.

The notching and boring rules of thumb for solid lumber are shown in fig. Structural floor joist repairs. 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.

Things might work out for a while but you will have a high likelihood that the floor will flex and your tile will crack. Roger goes over the best practices and rules for notching and drilling holes in joists while filming our bathroom series. 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. 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.

I jacked up straightened out the floor before gluing nailing and carriage bolting the new joist to the cut joist. Holes anywhere in the web area of engineered i joists except within 6 in. Sometimes joists are notched at the end where they bear on a wall or sill. Of walls and rim joists.