Floorboard/Joist Support

[quant2009]

Hi

I have just installed a freestanding bath into our bathroom. It runs in line with the floorboards which sit perpendicular on the floor joists (as per normal). The floorboards are 1 inch thick and sit on joists that are 2inches by 9inches. The joists is 12 inches apart. The rear claw feet of the bath (under where you sit in the bath) sit on top of each floorboard almost exactly halfway between each joist. The front feet I have positioned so they sit on top of a joist. Unfortunately I cannot position the rear of the bath on top of a joist as there is not enough room. Should (can) I support the floorboards on which the rear 2 feet sit by fixing another 2 joists with joint hangers (perpendicular to) between the two joists so that they give extra support to the floorboards on which the rear feet sit? Or is this unnecessary as the floorboards will take the weight anyway? Thanks all.

 

[anobium]

Probably unnecessary if your figures are correct, but just to be sure just insert a 25mm section beneath the feet of the bath long enough to sit on the joists.

 

[quant2009]

Probably unnecessary if your figures are correct, but just to be sure just insert a 25mm section beneath the feet of the bath long enough to sit on the joists.

Thanks very much for this. Just to be sure, are you saying that this 25mm section should sit on top of the floorboard and the feet placed on it, raising the bath 25mm? Thanks again.

 

[ajrobb]

That sounds pretty unsightly for a roll-top bath. You seem happy to lift floorboards. Could extra noggins under the feet take the concentrated load? I might be tempted to screw a an extra 25mm floorboard across the floorboards underneath the floor and feet rather than on top. I've no idea if that would be enough but 25mm floorboards on 300mm spaced joists already sounds strong. If nothing else, it should stiffen the floor to point loads.

 

[quant2009]

That sounds pretty unsightly for a roll-top bath. You seem happy to lift floorboards. Could extra noggins under the feet take the concentrated load? I might be tempted to screw a an extra 25mm floorboard across the floorboards underneath the floor and feet rather than on top. I've no idea if that would be enough but 25mm floorboards on 300mm spaced joists already sounds strong. If nothing else, it should stiffen the floor to point loads.

Thanks for this. I'll certainly put some extra support under the boards. As i suspected it may be a little over the top but saves me from worrying about whether the bath tub will end up in the dining room.

Cheers

 

[anobium]

Normal domestic flooring is joists at 400mm centres with 18mm t&g on top.
As I said before if you measurements are correct you dont need any extra support.
Putting some extra below the existing t&g will be a waste of time unless it sits on the joists and to do that you would have to take up all the boards.