Drill 3 1/2 " hole through 3 joists for toilet pipe

3/31/2020 at 11:20:54 PM

From the picture I don't like the look of it.

Don't totally quote me on this, you may wanted to get some more professional engineer's opinion.

However the general rule is that you needed at least 2 inch of solid wood above and under the hole + the hole can't be more than 1/3 of the hole.

So based on 3 inch drain (3.5 inch minimum hole) needed at least 10.5 inches (3x3.5 = 10.5 - 3.5 hole = 3.5 inch above and below hole) of height on the Joist to be safe

From the look of the picture I don't think it is nearly anywhere close..

Even when you double the joist and cut a hole like that, the wood have been weaken so much that it technically can't bare the normal weight. So I wouldn't be ok with this setup.

Also I don't know how the contractor have repaired the joist, did they used construction adhesive and nailed it with proper nail and pattern? Also how far away is the end of the joist from where the hole is cut out. It is all related information.

But as I said I won't trust this setup if it is our project.

However there are other engineer project that may allow things to work even with 2x8

4/1/2020 at 12:05:51 AM

Hi

Plumbing wise it looks up to code. Structural issues are there. We never drill thru joists more than 2.5 inches after all the city building Inspctor has the final say so I would reach them and get their opinion. If they pass it make sure u have it in writing

Good luck

4/1/2020 at 9:46:03 AM

Thank you very much Armando!

4/1/2020 at 9:47:01 AM

Thank you for your input GENE, it helps a lot!