Joist repair plate

[bluedog225]

I made a mistake I would appreciate any tips on fixing it.

Tl:dr-I put a 4 inch tall by 2 inch wide hole in three of my 2 x 12 x12 joists about 2 inches up from the bottom. Right in the middle of the span. What’s the best way to fix it?

Detail:

I have 21 joists supporting my loft. 2x12 They are on 16 inch centers. They span 12 feet. And are covered by three-quarter inch plywood.

I was running some 2 inch PVC through them for my plumbing vent. I put the first hole where I wanted it but miss-marked the remaining holes. I was in production mode and drilled three holes too low to allow the vent to drain.

I went ahead and raised them to where they need to be but now I have big 2 inch wide 4 inch tall holes in my 2x12s.

The holes start 2 inches up from the bottom of the joist on three joists affected.

That’s not gonna do. I have looked around and it appears there are steel joist mending plates available.

I’ve got three and three-quarter inches below the pipe to the bottom of the joist to work with. It occurred to me I could sister two by fours on either side of the joist. Glue and screw.

Thought I would check in with you guys before I start buying stuff.

Ps-there will be no pictures of the shameful work.

Thanks

 

[JoeMcGov]

It's not clear. Have you installed the PVC pipe through the shameful holes (and it cannot be removed)???

Sure would be nice if you had something that, oh, you know, said, say, 1,000 words.

 

[PCustoms]

Why does your vent need to drain?

 

[PCustoms]

Also a pic/sketch would be great. I assume you want to plug the existing hole and drill new

Depending where you drilled it you can probably just leave it, and drill new holes off to the side.

 

[bluedog225]

Fair point. I am asking for help

I have not installed the pipe yet.

 

[bluedog225]

Why does your vent need to drain?

When the roof vent gets rain in it, I need it to drain into the septic system rather than puddle somewhere in the vent system.

 

[bluedog225]

To be clear, when the pipe is in the uppermost position of the hole, there are 3 1/2 inches below it. Edit-3 3/4” below.

 

[PCustoms]

To be clear, when the pipe is in the uppermost position of the hole, there are 3 1/2 inches below it.

Too bad you didn't ask for help before you hacked the hole up, you could have left it and drilled new holes to the side.

 

[bluedog225]

That would’ve been smart. You’re right.

 

[PCustoms]

What would you have suggested?

Leave the hole.

Drill a new hole off to the side (I see the pic I posted doesn't have horizontal spacing).

Jog the vent pipe in one of the joist bays with a few 45's over to the new line of holes.

 

[PCustoms]

Can you sister in new joists?

Probably the quickest/surest option to fix.

 

[bluedog225]

Yeah. I’m looking at some 2 x 12 I was going to use for another project, but it can wait.

Will need to take out some blocking, but no big deal.

Maybe 3 feet? Glued and screwed with tight bond and big Simpson screws? Or maybe bolted in place.

 

[PCustoms]

Yeah. I’m looking at some 2 x 12 I was going to use for another project, but it can wait.

Will need to take out some blocking, but no big deal.

Maybe 3 feet? Glued and screwed with tight bond and big Simpson screws? Or maybe bolted in place.

At 12' and 3pcs I'd just do end to end.

Though thinking now, why 2x12 for only 12' span? Sister in full length 2x8 (double check me on a span table)

 

[bluedog225]

Thanks

Looks like I might get by with 2 x 8 but 2 x 10 would definitely work. That would avoid me having to take out some blocking they put on the underside of the plywood.

I really thought my mistake was gonna be that super hog throwing me off the ladder. Wasted half a day on this and will waste another half day tomorrow. Darnit.

 

[PCustoms]

Thanks

Looks like I might get by with 2 x 8 but 2 x 10 would definitely work. That would avoid me having to take out some blocking they put on the underside of the plywood.

I really thought my mistake was gonna be that super hog throwing me off the ladder. Wasted half a day on this and will waste another half day tomorrow. Darnit.

You'll waste a lot more days before you finish, goes with the territory...

 

[Rusted Nut]

Is that gray PVC, like for elect conduit? Don’t use that for plumbing, use ABS.

To fix your joist, remove the PVC, sister on 6’ strip of 3/4” CDX on one side, drill hole for new pipe, sister on the other side, drill hole, install pipe. Screw the 3/4” CDX every 6” across with 1 5/8” screws, screws spaced about 3” OC. I'm not a structural engineer, but that’s what I would do.

 

[PCustoms]

Im not a structural engineer, but that’s what I would do.

That's clear

 

[bluedog225]

Thanks. It’s regular white schedule 40.

 

[nmk_61802]

I've use these before for a notch just beyond the allowed size limits to get a toilet or bath tub where I wanted in a remodel:

Joist Repair Products

When it comes to Joist Reinforcement, whether the issue is overcut plumbing or electrical holes or notches, or if you want to route electrical and plumbing through the joists to keep it up and out of the way, we're the leading experts. Our patented Joist Reinforcers are just the ticket when it...

joistrepair.com

I don't see 2x12 but you could call, I would also assume 2x10 would work for your purpose.

 

[bluedog225]

I did find these online. I went out this evening and bought three new 2 x 12 x 12. Why not I ask myself? Just get er done.

They’re going be a bear to wrestle in the place though. Supported on one end by the top plate. And on the other end by a Simpson bracket. I may have some double Simpson brackets laying around here somewhere. If not, I can just screw them to the sistered joist and find a bracket later.

I am mostly sure that they toenailed in the ends before they put the Simpson bracket on. Hope it’s not too exciting when I take it off.


Going to be interesting. They are pretty heavy.

 

[acer66]

You'll waste a lot more days before you finish, goes with the territory...

That is referred to as learning on the job.

 

[billconner]

I have to wonder if 2x12s 16" on center with a 12' span isn't sufficiently over designed that it wouldn't be fine as is. The total depth of hole seems very close to the allowable 1/3 of the depth.

 

[acer66]

I think a 2x12 over a 12” span is not overbuild.
Exceeds code but that is the very bare minimum and gives you a very bouncy floor if go with that.
Using 2x’s I go 1” height per foot of span but
I am also a bit on the husky side of things.

 

[manwithtools]

I did find these online. I went out this evening and bought three new 2 x 12 x 12. Why not I ask myself? Just get er done.

They’re going be a bear to wrestle in the place though. Supported on one end by the top plate. And on the other end by a Simpson bracket. I may have some double Simpson brackets laying around here somewhere. If not, I can just screw them to the sistered joist and find a bracket later.

I am mostly sure that they toenailed in the ends before they put the Simpson bracket on. Hope it’s not too exciting when I take it off.


Going to be interesting. They are pretty heavy.

Interesting assortment of fasteners for a commercial product. I see Phillips, Robertson and Torx.

 

[LB-1911]

That is referred to as learning on the job.

aka "Gaining Experience"

 

[acer66]

Interesting assortment of fasteners for a commercial product. I see Phillips, Robertson and Torx.

Good catch and using different types of fasteners is always a sign that a true professional is at work.

At least that is what I tell people.

 

[bluedog225]

One down. Getting these things to the second floor was fun. These just the limit of the size board I can handle anymore. Overhead up on the ladder.

Glued and screwed. Good as new.

I hate unforced errors. Great example of target fixation.

 

[billconner]

I think a 2x12 over a 12” span is not overbuild.
Exceeds code but that is the very bare minimum and gives you a very bouncy floor if go with that.
Using 2x’s I go 1” height per foot of span but
I am also a bit on the husky side of things.

2x8s 16" o.c. over 12' is good for 1:360 deflection which isn't very bouncy.

 

[manwithtools]

2x8s 16" o.c. over 12' is good for 1:360 deflection which isn't very bouncy.

Yep, as you said earlier 2x12's on 16" centers is pretty overkill. But's let's not forget his cabins floor structure is pretty overkill too 14" LVL's on 12" centers for a 24' span. I think the architect he used must have been sued at some point in time

 

[bluedog225]

Yeah, there’s no bounce upstairs or downstairs. Got the second one in. It was tougher because after adding the joist, there was no room between the two to screw it. But I had Aleady applied the PL premium. I managed to get it done with the right angle drill and various length Simpson SD screws.

I’m going take a break . That third one may have to wait for another trip.

Project splash down for the toilet has to be postponed.

 

[acer66]

2x8s 16" o.c. over 12' is good for 1:360 deflection which isn't very bouncy.

Maybe I have the dreaded high bouncy sensitivity syndrome.

 

[reader2580]

Interesting assortment of fasteners for a commercial product. I see Phillips, Robertson and Torx.

To me, it looks like someone stripped out square drive screws, not used other styles of screws. It sure wouldn't stop me from buying if I had a need for the product. Oh no, someone in marketing stripped out a couple of screws when building a demo and chose not to replace them.

 

[manwithtools]

To me, it looks like someone stripped out square drive screws, not used other styles of screws. It sure wouldn't stop me from buying if I had a need for the product. Oh no, someone in marketing stripped out a couple of screws when building a demo and chose not to replace them.

Okay even better for product endorsement - stripped out Robertson's. Let's put those damaged fasteners in our add copy. I just think that says volumes about a companies approach to their product quality.