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?