Can You Notch A Floor Joist

Sometimes on a remodel you can t install a full length floor joist because of plumbing existing walls or finished floors or ceilings.

Can you notch a floor joist. Doubling of joists is recommended under walls heavy objects like tubs and at large openings. As you would imagine any notch or hole made in a joist will weaken it so if you can avoid making them then this is the best course of action even if it means re routing pipework or cables. Away from any end or load bearing wall second photo. If you have manufactured i joists you can drill holes up to 1 1 2 in.

The notching and boring rules of thumb for solid lumber are shown in fig. Doubling of joists can solve alot of problems like sagging uneven or undersized floor joists. Notching and boring of joists and rafters section 91 2308 8 2 joists 91 2308 10 4 2 rafters b notches at the ends of joists or rafters shall not exceed one fourth the depth. 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.

Installation can be difficult as the sheeting must be bent to fit over the tops of the joists. You ll need to use a sheet metal brake to bend the sheets. These joists may need reinforcin g to reduce bounciness sagging or excessive deflection in the floor or ceiling. This is a process that can t be completed by hand.

You can notch and bore joists without sacrificing critical strength but you must follow the rules. If your home is more than 20 years old your floor joists are most likely solid wood 2x8s 2x10s or 2x12s. Floor ceiling rafters 7 8 1 3 8 1 13 16 2 5 16 2 13 16 depth of notches located between the ends middle 1 3 of the span 9 16 15 16 1 3 16 1 9 16 1 7 8 length of notches. If you don t have access to one you ll need to get your metal sheets bent for you by a local metal shop which can be a chore.

Diameter almost anywhere in the web area the area between the flanges. Just stay 6 in. Holes bored in the joists or rafters shall not be within 2 inches of the. Illustration of the rules for positioning notches and holes into floor joists.

Often hole size can be increased and holes can be placed closer to bearing than shown on the chart based on actual design spans and loads. You can drill the holes anywhere along the length of the joist first photo.