Bathroom floor joists loading

[rob_a]

Hi all, my 1st post here

We're planning a refurb of the bathroom and want to put in a new steel bath. However, the bath will be alighned with the floor joists (170mm x55 @ 370mm apart Edwardian house). The bath weighs 55Kg with capacity of 150 litres (150kg) so say 205 kg when full. The feet wont be resting directly on the joists and are 480mm apart width ways. One set of feet will be 600mm from a load baring wall and the other 1440 from the same load baring wall and 1560 from the other load baring wall. The floor will be either 18mm ply or 22mm ply screwed down.

My question is will we end up with the bath in the kitchen below the first time we fill it or will this be ok?

Oh and we want to tile the floor with 300mm square slate tiles. Obviously the thicker the ply the better but as the bathroom is only 2m x3m max with joists every 370mm running across the width of the room (2m) would 18mm be ok (save weight on the joists)?

cheers Rob
ps great forum guys!

 

[JohnD]

will the feet of the bath be visible when fitted, or will it be panelled in?

do the joists run from one end of the bath to the other, or at right-angles?

 

[Symptoms]

Rob - spread the load if you're worried. Most baths come with 4 or 5 adjustable feet (bits of threaded studding with plastic feet) so what you do is to place the feet on lengths of 75 x 50mm timber which spread the load across the joist positions Compensate for the timber thickness by feet adjustment. Of course, you may still get the bathing Mother-in-law dropping into the kitchen if your joists are in poor condition - so check them out for rot & bug.

 

[rob_a]

Thanks guys.

The bath will be panelled in and the joists run from one end of the bath to the other. I've had the floorboards up and they look in good nic still.

I'll put a length of timber under the pairs of feet. Someone posted a caclulation for the load bearing of a joist so I'll go in search of that too.