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Support For Bathtub


Registered User
May 1, 2021
raleigh nc
@ ! @


From the `15 IRC,
View attachment 2538

While no specific requirement for supporting a freestanding tub
is in the Codes, the framing underneath must be able to support
fully the loads imposed on them.

FWIW, ...a lot of construction managers & contractors are known
to talk the talk, but NOT be able to support it with actual Code
references. :mad:

@ ! @
Thanks Seth. So here is how I ended up at this forum. I have rebuilt a 1300 sq ft house in Raleigh - all new framing in every direction. 2nd bathroom will get a tub, (like the cat iron pictured a few posts up) Tub with 60 gallons weighs about 750#s, then the big faucet and plumbing have to add at least 10#s and I weight 200. It is a two person tub, so that adds a tiny bit more. either way we are about 950 with just me. at 121/2 sq ft or so of overall load space that is about 75lbs per sq ft. This house started out as a 600 sq ft bungalow and was added on and on over the years - hence having to totally rebuild. it is on a crawl space and there are numerous foundations, not just a simple rectangle. we put new, treated sills, band and the entire floor system. this particular span is about 10'. we used some 2/10s where the tub was going to be (not knowing the actual weight when we built) and the rest of this part of the floor system is 2/8s. we did do a box in (have to get pics to explain) as per the framer for extra strength. now that I know the actual weight not sure if it is strong enough. Options I have considered ; pouring a pier or two and using a 6x6 treated to sit under the floor joists resting on the pier - that would distribute the weight to the ground and take a lot of strain off the joists, no? I got the idea from the way the engineer designed the cathedral LVL system, 5 piers, one post at 15' thoughts?


Sep 11, 2013
Moving in the right direction, shorter span, closer spacing, add pier, better support. no inspection in your area?
My 1905 has a C.I. claw and ball on original framing and it supports both of us.