Cutting Holes In Floor Joists For Hvac

The band joists are to stabilize the end of the joists.

Cutting holes in floor joists for hvac. 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. Heading off and framing floor openings. General notes general notes allowed hole zone suitable for uniformly loaded headers and beams only. It might be wise to make the hole so there are at least 2 joists at least on one side of the cut.

I never had an inspector cite a band joist not being cut properly. In a perfect world any floor joist that is cut should have a header installed preferably two and doubled adjacent joists. Hvac can run parallel to floor joists though and there are code acceptable ways to cut holes into joists but generally those holes are not big enough for hvac ducts only plumbing and electrical. Proper way to cut a joist and go to images.

Where and how to drill joists for electrical cables or plumbing runs depends on what type of floor framing you have. Trus joist tji joists. Rules for holes in joists. 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.

The hvac should have gone up a wall not laterally under a floor by cutting joists. Minimum distance from table b 1 round holes may be cut anywhere in web outside of hatched zone if. From the top and the bottom if it s a dimensional lumber joist. The maximum allowable diameter of a hole in any solid lumber joist is one third of.

Sometimes joists are notched at the end where they bear on a wall or sill. Contractors may cut through floor joists to accommodate plumbing or hvac mechanical equipment as long as they properly transfer the floor load to adjoining joists by adding headers. No holes in cantilevers. Keep the hole at least 2 in.

Please follow these rules for making holes in joists. Permitted if the group perimeter meets. Tradespeople often need to cut notches or holes in floor and ceiling joists to run pipes ductwork or wires. Minimum applies to all holes except knockouts closely grouped round holes are.

I would make the hole larger than 8 for an 8 duct. 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. The rules for positioning notches in floor joists image courtesy of niceic to understand the forces at work in a joist particularly the tension and compression forces please see our project that explains how the forces that affect buildings work. They are located 3 away horizontally edge to edge from a larger hole.