Cutting Holes In Floor Joists

Please follow these rules for making holes in joists.

Cutting holes in floor joists.

They are located 3 away horizontally edge to edge from a larger hole. In order to maintain the support integrity of the ceiling or floor joist or rafter system it is important that if joists are cut that the load that was bearing on those joists be transferred to a modified support system. Rules for holes in joists. Of walls and rim joists.

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. A hole saw is a short tube shaped cutting tool with drill bit through the center of the cylinder and a. Drill holes with a diameter of no more than one third the depth of the joist staying 2 in.

As part of any new installation work or a re wire a cable trunking or cable tray sometimes has to pass through an element of building construction such as a floor wall or beam necessitating the formation of a notch or opening in the element. Holes cannot be closer than 2 to. 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.

For a 2 10 where actual depth is 9 25 inches the maximum allowable hole diameter would be just over three inches. If the joist is 12 inches deep you need a hole saw that is 4 inches in diameter or smaller. 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. If you have manufactured floor joists you will want to consult the particular manufacturer s literature.

The diameter of holes shall not be greater than 1 3 the depth of the floor joists. Cutting notches and drilling holes in joists. Trus joist tji joists. Minimum distance from table b 1 round holes may be cut anywhere in web outside of hatched zone if.

Refer to the hole chart on page 9 of the tji specifiers guide for uniformly loaded joists. Minimum applies to all holes except knockouts closely grouped round holes are. Away from the top and bottom. Cutting and or removing joists to provide an entry or access can be the most difficult part of the overall project.