[HMimprover22]

Adding a shower to 2nd floor 1/2 bath. Need to run 2 1/2” drain pipe through 4 joists. Problem is 1947 cape has only 6” joists. Any suggestions how to accomplish this without effecting joist integrity. This size hole is not appropriate for this size joist (too big). Stud Shoe? Sister joist? If sister joist it can’t run entire length since I only have exposed portion where bathroom is located and the few feet where drain goes. Any suggestions? Thanks

 

[dj3]

What size are the joists?

 

[Msradell]

Re: Pipe through 6” joist

What size are the joists?

He stated in the original post that they are 6".

 

[Nealtw]

I wouldn't do it. Can you drop below it and build a drop to hide it.

 

[dj3]

On a 2x6 you can only bore a 1-1/2" hole.

 

[HMimprover22]

On a 2x6 you can only bore a 1-1/2" hole.

right I understand that so looking for ideas on alternatives.

 

[HMimprover22]

I wouldn't do it. Can you drop below it and build a drop to hide it.

that’s an idea. Will have to see how that would look from first floor but definitely an option. Thanks for the idea.

 

[Nealtw]

Re: Pipe through 6” joist

that’s an idea. Will have to see how that would look from first floor but definitely an option. Thanks for the idea.

In new construction, that just happens with out discussion. We get to in after and build the boxes. :wink2:

 

[carpdad]

Re: Pipe through 6” joist

https://www.metwood.com/joist-reinforcers/


Call the company and ask if there is such a hardware for 6" joist and how plumbing may be sloped through. May also depend on the lumber condition, knots, splits, age, etc. Take photos and make the description as accurate as possible. Who knows? It's engineering may be set in its ways, so ask if using 2 per joist, back to back and bolting them together? Make your own with thicker metal plate (1/4"?) with the hole drilled out? The pictures "suggest", though, that the holes are in the center. Joist load points are, if I remember, along the edges.

 

[huesmann]

The sectional area of 2.5" pipe is 5 sq in. If you can only have a 1.5" bore, how about 3 penetrations? Make two manifolds with reducers, tees and elbows.

Is there a rule on joist penetration spacing?

 

[dj3]

The metal joist reinforcer (answer #9 above) may be useful, if approved by your building department. Find out.

 

[House Designer]

Why are you using a 2-1/2" drain pipe for a shower? Most houses I see use 1-1/2" pipe.

 

[HMimprover22]

Why are you using a 2-1/2" drain pipe for a shower? Most houses I see use 1-1/2" pipe.

. Code in my area is 2” drain. The home to be cut needs wiggle room so therefore 2 1/2 inch hole.

 

[Nealtw]

Re: Pipe through 6” joist

Why are you using a 2-1/2" drain pipe for a shower? Most houses I see use 1-1/2" pipe.

Not for a shower, you are thinking tub.

 

[TheEplumber]

Re: Pipe through 6” joist

. Code in my area is 2” drain. The home to be cut needs wiggle room so therefore 2 1/2 inch hole.

Showers are indeed 2". And I have always drilled 2-9/16" holes. Any tighter and you risk pipe squeeking when it expands from hot water.....

So, you have 6" deep joists. How are you going to conceal the P trap?
Do you have the vent location figured out?
Have you thought of running parallel to the joists and moving the drain stack?
Have you thought of a mud/tile base utilizing a trough drain at the rear? This would put the pipe and trap near a wall that you could soffit......

 

[carpdad]

Re: Pipe through 6” joist

A plumber chops up my carefully framed sentences.:smile::smile:
OP: maybe a picture would help with how it can be done and be connected to a main drain.