# Framing Question: How thick the wall that carries plumbing?



## jaes

I am remodeling a kitchen and bathroom. Both rooms are next to each other, separated by a 4 1/2" wall. I am simply moving the wall over into the kitchen area 2 ft, so that the now 3 ft wide bathroom become 5 ft wide, and big enough to accomodate a standard size bath tub (this is an older house). The OLD WALL (before remodelling) was framed with 2X4s---that wall carried much of the plumbing for the bathroom (on one side) and the kitchen (on the other side). FOR SPACE REASONS (every inch counts), I want to frame back the new wall using 2x4s ---however, a friend suggested that a wall that carries plumbing should be framed using 2X6s. QUESTION: Does code require that such a wall be framed with 2x6s or is it a matter of being nice to the plumber? ---I know, plumbing in a 2x4 wall is tight---but if you knew my space limitations, you would know why every inch (in this case 2"s) count. I would appreciate any help with this question. Thanks. ---Jaes.


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## Termite

Walls that carry plumbing are called "wetwalls." They're often made from 2x6's in what are normally 2x4 houses for convenience. Unless the structural requirements of the building dictates, you can use 2x4's for a wetwall. The problem can be that the diameter of the pipes and the thickness of the required nail protection plates can actually put a little bow in the wall. Plus, you lose all the tensile strength in the top plate since there's no wood left if you're using 3" pipe.


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## jaes

Thekctermite: --Thanks for the reply---Your words lead me to believe I should go with a 2X6 wall--- I'll just have to deal with the space problem in a more creative way. ---Thanks, again, for the help. --Jaes.


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## buletbob

if its new construction yes i agree with the above post. but when you get into remolding there are things that must be done differently .
if its not a bearing wall ,which in most cases are not. and room is a problem you could go 2x4 and add 3/4 furring over the one side. because most plumbing here on the island that runs through the walls are 1-1/2" for bath rooms and 2" for kitchen sinks. all the 3" we bring down to the basement or floor joist and branch off from there. If you must drill up through the top plates just make sure you block both sides of the hole to support the wall. BOB


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## jaes

Wow, I very much appreciate the two replies to my question. I learned a lot from both of you who took the time to help. ---Thanks, Jaes. (This is a great forum.)


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## Ron6519

Does the wall contain a cast iron waste pipe? Or even a 4" PVC pipe? They won't fit into a 3 1/2" cavity. Even witha 3" waste/vent combo, the space would be tight(read bulging sheetrock).
Ron


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