New Upstairs Bathroom - Joists

Postby andrewmcgregor » Sun Dec 26, 2010 11:18 pm


I'm planning on turning a 1st floor bedroom in to a bathroom.

I've heard I need to "double joist" because of the weight of the bath.

I can't find any information or details on calculations for this.

Assuming double joisting is the way to go, does the extra joist get attached to the original joist, i.e. so the first joist ends now support the load from both; or must the double joist be supported in its own right from the brick walls/joist hangars?


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Simply Build It

Postby stoneyboy » Tue Dec 28, 2010 12:39 pm

If you are going to fit the bath along the side of the room where the joists go into the supporting wall and it's not a cast iron bath you'll be OK.
If it's a cast iron bath and it's only going to be standing lengthways on two joists then strengthening is adviseable. Doubling up the joists without building-in should be adequate. Make sure the feet have sound flooring to stand on.
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Postby andrewmcgregor » Tue Dec 28, 2010 9:51 pm

Thanks for your reply. It won't be a cast iron bath and it will run along the external wall spanning ~5 joists.
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