What is the maximum hole size in joists?

3-3/4 in.





Keep the hole at least 2 in. from the top and the bottom if it’s a dimensional lumber joist. 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 11-1/4 in.) is 3-3/4 in. diameter—plenty big enough for running cable!

Where do you drill holes in joists?

You can drill the holes anywhere along the length of the joist (first photo). If you have manufactured I-joists, you can drill holes up to 1-1/2 in. diameter almost anywhere in the web area (the area between the flanges).

How do you drill through ceiling joists?

When drilling holes in joists, always drill in the center of the joist itself.

  1. Holes drilled into joists should not have a diameter greater than 0.25 times the depth of the joist.
  2. When spacing holes, try not to put them closer together than 3 times the diameter of the holes.


How big of a hole can you drill in a 2×10 floor joist?





The maximum allowable diameter of a hole in any solid-lumber joist is one-third of the joist’s depth. Notches can’t be deeper than one-sixth of the joist depth. In the case of your 2×10 joists, the maximum diameter is 35⁄64 in. (91⁄4 in.

Where should you not drill holes in joists?

Rules for boring/drilling holes



You can put holes in floor joists anywhere along the length of the joist, but you can’t put them any closer than 2″ from the top or bottom edge of a joist. The maximum size of a hole is 1/3 the depth of the floor joist.

What are the requirements for holes and notches in joists?

Joists and rafters



The maximum allowable depth of notches is one fifth of the joist or rafter depth or 32 mm, whichever is less. Holes may only be located within a length measured from the face of a support that is no more than three times the depth of the joist or rafter.

Can you drill a 3 inch hole in a 2×10 floor joist?

Simply following building code, you’ll only be allowed to bore a 3-5/64″ hole through a 2×10 joist. A 2×10 is actually only 9-1/4″ deep, and building codes set the maximum hole size to 1/3 the depth of the member (9-1/4″ / 3 = 3.08333″).

How do you reinforce joists with holes?



Quote from the video:
Quote from Youtube video: By adding a joist reinforce or you can double the size of the hole to a six inch diameter on either a two by ten or two by twelve. And according to testing this will actually make the joist. Stronger.

Which type of joist has perforated knockouts?

Nordic I-joists provide knockout holes along the length of the joists to facilitate the installation of electrical wiring or light plumbing lines.

Can you put waste pipe through joists?

Can a waste pipe go through a joist? Running waste pipes through joists should be avoided where possible, as any drilling of joists (also known as notching joists) may weaken them and compromise the structural integrity.

Can you drill through an engineered joist?



In engineered I-joists, you can drill holes up to 1-1/2 inch diameter almost anywhere in the web area between the flanges, provided they are at least 6 inches from the end of the I-Joist or load-bearing wall. You can drill holes up to 4 inches in diameter in the middle of the I-joist.

Can you drill through a rim joist?

Since the rim joist is continuously supported by the walls or foundation it rests on, the strict notching and hole-boring rules don’t apply. Just don’t create a large hole or notch directly under a group of studs that support the end of a beam, or a window or door header above.

Are rim joists load bearing?

On a deck, the rim joist isn’t typically considered load bearing unless a wall is built atop it. But it’s still very important. They provide strength to the floor joists and keep them upright just like the floor joists inside a house.

Can you run dryer vent through rim joist?

If your dryer is in the basement and the basement is underground, run duct up the exterior wall and out the rim joist. Set the vent a minimum of 12 inches above the outside ground. Pro tip: Use no more than 25 feet.

What is the difference between a rim joist and a band joist?



A rim joist’s relationship to the joists is similar to what the top or bottom wall plate is to the studs. It is also confusingly called a header (header also refers to other framing components) or rim board. Collectively, the end joists and rim joists are called band joists, especially in regard to deck construction.

Should rim joists be doubled?

It is advisable to increase the rigidity and strength of your deck’s rim or perimeter in order to reduce bounce and provide a solid foundation for your rail system. This can be accomplished in a couple of ways. You may want to install double rim joists across long sections to respond to the flexibility of the material.

Can you sister a rim joist?

To fix a damaged band joist, the best method is called “sistering.” This means a healthy board is placed next to the damaged section, and the two are attached. Sistering allows the healthy board to take on the load-bearing function, without risking any damage to the overall structure by trying to remove the band joist.