# Can You Cut Floor Joist For Plumbing? (Detailed Guide)

You’re not allowed to do any notches in the middle third of a floor joist span, and you’re not allowed to notch the bottom side of members over 4″ in nominal thickness. You’re allowed to notch 1/6 of the depth and 1/3 of the width. You can’t notch either of them, because they’re too short.

If you want to make them longer, then you’ll have to go back to the drawing board and figure out a way to attach them to each other. This is a very common problem, so it’s a good idea to be familiar with it before you start working on a new project.

Here’s a great Youtube Video that illustrates our ideas

## Can you cut through joist for plumbing?

You can safely drill joists for electrical and plumbing runs without weakening the joists, if you follow the rules. They are the experts of The Family Handyman Magazine. The hole needs to be at least 2 inches in diameter. If you are building a new home, you can drill a joist for the first time in the basement or crawl space.

If you already have a basement, a crawlspace, or an attic, then you don’t have to worry about drilling a hole. You can use a drill press to do the job, but you’ll need to be careful not to damage any of the framing.

## How much can you notch a floor joist for plumbing?

Notches on the ends of joists shall not exceed one-fourth the joist depth. The top of a rafter shall extend not less than 1-1/2 feet (305 mm), measured from the centerline, to the bottom edge of an adjacent stud.

## How big of a hole can I cut in floor joist?

The maximum hole size for a 212 joist is 3 inches, which is one-third the depth. If the hole is too small, it will not be able to support the weight of a load, and the load will be transferred to the floor joists, which will then be damaged. If you have a large hole, you may want to consider using a 3×6 or 4×8 hole instead.

## Can I run a waste pipe through joists?

A pipe may not beched if it has a hole in it. If the hole is large enough, it may be difficult to see through. The hole may also be covered by a layer of dirt or other material, which may make it difficult for you to determine the exact location of the notches.

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

You will only be allowed to bore a hole through a 2×10 joist if you follow the building code. The maximum hole size for a 2×10 is set by the building codes at 1/3 the depth of the member. So, if you’re building a 4×4, then you can only bore 1″ into the joists.

If you want to build a 5×5 or 6×6 (or any other size), you will need to drill a hole at least 3″ deeper than the hole you just drilled. This will allow you to use a larger hole saw to cut through the plywood.

## Can I notch the bottom of a joist?

Notches can only be made in the top OR bottom of the joists, (not both) within the permitted area to a maximum of 35mm. The maximum thickness of the holes can only be made on the centreline within the permitted area. Holes must not be less than 1.0mm in diameter and not more than 2.25mm deep. The maximum depth of a hole is 5mm, and the maximum width is 3.75mm (the width must be the same as the depth).

The width of each hole shall be equal to or greater than the height of any adjacent studs, except that the width may be reduced by up to 25% if it is necessary to reduce the number of holes in order to comply with the requirements of this section. If a stud is to be used as a support for a wall, it must have at least one hole in it for each 1m2 of height above the floor.

A stud may have two or more holes, but only one of these holes shall have a diameter of less or equal than 3mm and shall not have any other holes that are not required for the support of that stud.