Strengthening bathroom floor to support a cast iron bath

[Jamesjf1]

(Sorry if this subject is already on here, but I can't find it. Please point it out for me if it does).

I've bought a big, old cast iron bath (very heavy, but couldn't give any sort of accurate weight) to fit in our ground floor bathroom. It's approx 6' x 34", with the usual 4 ornate feet.

The bathroom has a suspended floor of 28mm floorboards over 6.5" x 2.5" joists spaced at approx 18" centres. Does anyone have any thoughts on whether the joists/floor would need strengthening and, if so, how?

The feet of the existing acrylic bath are each supported on short lengths of 2" x 1", which spread the load on each foot across the width of 4 160mm wide floorboards each. I wouldn't want this with the new bath, as the underside is exposed and on view. Would adding a second layer of floorboards on top of, and perpendicular to, the existing floor serve any load-bearing/spreading benefit (as I would prefer an exposed floorboard finish)?

Thanks

 

[TicklyT]

Once you know exactly where the bath will be, you could lift a couple of floorboards and fit some noggins between the joists directly under the bath feet.

As you are on the ground floor, a sleeper wall or a couple of brick piers under the joists below the tub may help add even more rigidity.