joist structural integrity is crippled
I am just beside myself with this problem. During my basement renovation, a plumber cut a 4 inch hole into my 2×10 joist. Unfortunately there is only one inch of wood from the bottom of the hole to the bottom of the joist. The plumber cut the hole at a 45 degree angle into the joist. His explanation for this was that to maintain the pitch of the drain pipe, he had to cut the joist this low. Now the floor above the joist is alocated a pedatal sink. The damage is done, and I know that this was done incorrectly, but how do I go about remedying this serious problem? Two options that I am cosidering is to place two 3/8″ steel plates the width of the joist notched out at the drain pipe on either side of the joist and then using lag bolts across the joist. The other is to use 1/2″ plywood on either side of the joist. The cutout for the plywood and steel would either be on the side so that the piece would look like a letter “C , or on the top so that the piece would be like a horseshoe. Any advice would be greatly appreciated. The joist was cut approxiamtely 8-10 ” from the end which has 4″ resting on a steel I beem, and the joist is approx. 14″ long.
Replies
You may find this helpfull:
http://www.amlegal.com/nxt/gateway.dll/NC%20Residential%20Code/part00382/chapter00657/section%20head00661/section00680/subsection00682.htm?f=templates$fn=main-nf.htm$3.0#JD_FigureR502.8
Here's another thought: You could double up the joists on either side of the affected joist and header off the section that has the hole in it.
By the way, I've seen worse. Not condoning, just stating. And usually with no noticable effect on the structure.
Hope this helps.
what the heck
was I thinking?
First thing, relax.
Breathe
In
out
It's not quite serious enough to be beside yourself.
Pissed at him maybe, yes!
Anyway, if I got this right, you have a 4" hole a little lower than halfway in a 2x10 joist - only one of them. And this hole is positioned so that you have a portion of the bottom of the joist about 1"x1-1/2".
Forget the plywood or plates along side. The only strength they will provide is the one inch at the cutout which ain't much. What you want is strap steel along the bottom of the joist, screwed up into it ( probably a good idea to miss the drain line with the screws) for about two feet to either side of the weak spot. OK 14" on one side. stretched tight when installing it.
BTW, is your joist sagging?
If it is, it should be jacked up when doing this.
Excellence is its own reward!
Bridging (a thing of the past?) helps distribute the load on any particular joist to it's neighbors. You could install 1x4 cross bridging with the top ends construction-glued and wedged in and nailed at the bottoms, or use solid 2x10 blocking. But as others have said, your joist in question may not be compromised.
Wolffdog
Piffin's idea is best. To apply plates with bolts actually compounds the issue, adds strength while removing more wood.
You probably do not have an issue but if there is a possible leaking water source overhead you will in the future.
The bottom strap 1/16" - 1/8" thick 1 1/2" wide spaning the penetration by 14" or more either side reduces stress at the top of the joist.
I like the idea of anchoring this to the plumbing but maybe that's a bad idea.lol
For future I used to tell all my plumbing subs that any structural penetrations greater then 30 percent of a framing member needed my approval. Didn't work half the time but was able to through the retro fit work cost back on them.
Cover the joist with a sheet of plywood. Then jack it up a bit and then nail. Running the board lengthwise, thicker plywod or gluing will make it even stronger.
How's he supposed to cover it with ply when there's a 4" pipe running through it?.
Excellence is its own reward!
The plywood is nailed to the bottom of the joist, not the side. Ever notice how much stiffer a floor is after it is drywalled underneath?
Since your plumber's handywork is only 8-10" from the end of the joist, most of the stress in the joist is shear, not bending stress. If the notch was in the center of the span it would be much more serious. I would go with Piffin's idea of bolting on a steel plate or angle to the bottom of the joist.
'Course you could do what I've seen in a lot of old basements, just jamb a 2x4 under the joist as a post.
i like the idea of "heading it out" the best. just install 2x10s with minimum clearance perpendicular to the joists and parallel to the pipe. shore it up to level before you cut and install the headers, then remove temporary shoring. be generous with framing clips when fastening.