Notched Joist Problem

[RicodJour]

Not sure where you're located and what your local code is, but the NY State IRC (International Residential Code with minor modifications) prohibits notching in the middle third of the span. That 8" puts the notch in the middle third.

The depth of the notch, if it wasn't in the middle third, is of an acceptable depth - depth of notch/6 = 1.5"

It's not a great situation. You may never have a problem, but your contractor damaged your house and it doesn't conform to the IRC. Ask him what he's going to do to strengthen the weakened joists. Sistering a 3-4' 2x6 or 2x8 under the notch would stiffen the localized weakness. The added pieces should be glued and nailed.

Generally, whenever an electrical or plumbing line is run perpendicular to the joists it should be drilled instead of notched. It doesn't weaken the joist as much and keeps the line away from the face of the joist, thereby preventing someone inadvertantly hitting it with a nail.

R

[BN]

My contractor notched my joists in the kitchen about an inch from the top. The floor joists are 9" in height and 1 1/2" inch in width and 15' in length. It is under the kitchen. The notch cut is about 1" cubed in volume and at the top. Also the notches are 5' 8" from the start of the span. Every joist was notched the same way to fit a gas pipe (black pipe).

How bad is this? Is it something to lose sleep over?

THanks

[tbasc]

WWPA has a pdf describing limits of notching. I'll e-mail a copy on request.

Alternatively, give the group the same kind of info that BN provided and you will probably get an answer. TB

[kevin]

This isn't a troll, and I don't have anything to offer regarding the OP notch question. But supposing the plumber _did_ drill holes near the centerline of the joists. How do you then go about getting the piece of rigid black gas pipe in those holes? Do you cut an access through the exterior of the house? Do you use lots of short lengths coupled together? Just curious...

-Kevin

[George E. Cawthon]

The notch has reduced the effective depth of the joist by the depth of the notch. So assume the notch is 1 inch deep the effective depth of the joist is 9" - 1" = 8"

If that is a 15 foot clear span (no support except at the ends) it is either unacceptable or close to unacceptable depending on the joist spacing. Based on my tables you should have 2 x 10's and they should be Douglas fir or larch on 16" centers as a minimum. The plumber should have put the pipe through holes near the center of the joist. That would not reduce the strength of the joist whereas a notch on the top or the bottom does reduce the strength

[BN]

The kitchen is 15' x 10'. The joist span is 15'. There are 6 joists that are 14" apart. The 1st and last joists are 6" from the joist-parallel wall. Although there is a double joist 2 feet from the wall and one more 5 inches from the double joist. So its a total of 6 joists spaced 14" apart but starting 6" from either wall plus the 3 joists I mentioned for a total of 9!

Luckily the double joist is under the cabinet and range side of the kitchen. We may put granite or quartz countertop.

Does that change anything?

[Wayne Whitney]

For ridgid pipe, I would think exterior access would be the way to go. You could also use a flexible gas pipe, i.e. corrugated stainless steel pipe (CSST) or annealed copper.

Of course the point of the original post is that the plumber should have made sure the notches were not in the middle third of the span.

Wayne

[Brad Bruce]

How would you install the gas pipe the OP had installed? I guess you'd have to hang it below the joists.... I'm serious. I need to have a gas line moved in the near future.

Brad

[Michael Daly]

If you can't hang rigid pipe below the joists, you can get flexible gas line and run it through holes in the joists.

Mike

[Greg O]

Ask a supplier about "Ward Flex", or "Gas Tite". Generic name SST, stainless steel tubing. If you can pull a garden hose through, you can get flexible SST through. Greg

[DanG]

Not really. The span table that the code official uses will make the difference. The joists are not 14" apart. They are on 16" centers - the distance from face to face is 14 1/2".

I don't think your floor is going to cave in, but it has been rendered sub code. Here is a span table:

also have a span calculator: (top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) [e-mail]