Can You Notch The Bottom Of Floor Joists

Holes anywhere in the web.

Can you notch the bottom of floor joists. Sometimes joists are notched at the end where they bear on a wall or sill. See the bottom right of the page where it says do not cut or notch flange it is typical of all i joist manufacturers installation documents. Occasionally concerns arise about notches or holes cut in trus joist tj products used in continuously supported applications such as rim board. As iggy pointed out the i joist in question needs to be reinforced similar to a cantilever reinforcement.

If you have manufactured i joists you can drill holes up to 1 1 2 in. Illustration of the rules for positioning notches and holes into floor joists. In fact most have little perforated knockout holes that can be punched out with the swing of a hammer. Notching wood and boring rules engineered i beam rules.

Point your home builder to page 9 of weyerhauser s i joist document here. Before you start work check that the joist size is adequate for the span. These joists may need reinforcin g to reduce bounciness sagging or excessive deflection in the floor or ceiling. Can be drilled in the middle of the.

Just stay 6 in. 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. We never recommend notching joist flanges but small notches may be permissible in some situations based on joist span and loading. In situations when sistering damaged floor joists with lumber of similar dimensions it can be easy to notch and slide the sister board into place.

You can drill the holes anywhere along the length of the joist first photo. Take some extra time and jack the damaged area up so that the new lumber doesn t need to be. However doing this does not fix the slant that the floor has taken since the old joists got damaged. You can never ever ever notch or bore through the top or bottom flange or chord.

Attaching a metal strap to the bottom edge of the joist can stabilize a notched joist increasing the tensile strength of the joist. You can drill 1 1 2 in. Although rim board is generally not required to span a distance while supporting the vertical load like joists and beam members it is a critical structural component. Holes up to 4 in.

Away from any end or load bearing wall second photo. 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. Diameter almost anywhere in the web area the area between the flanges.