Installing Bath

[stevedo]

I'm looking at a bath that from the specifications weighs 85KG empty and up to 400KG when full to the brim. These weights exclude any occupants

I'm a competent DIY er having fitted 4 bathrooms previously. However, I'm not sure if a bath of this weight would require the floor to be reinforced at all? The bath would be installed on the first floor with what I would call normal joists. If it helps at all, the house was built in 1971.

Would any reinforcement work for a bath of this weight be required? If so, I'll probably have to have a rethink.

Thanks in advance
Steve

 

[JoeMar]

please elaborate on 'normal joist' - size, spacing and span??

 

[stevedo]

here goes

depth = 170mm
width = 45mm
spacing = 400mm
span = 3200mm

 

[RonnyRaygun]

And the size and position of the bath??

Another issue is that the load will probably come down onto four feet, meaning some joists will take more of the load than others...

 

[hotrod]

here goes

depth = 170mm
width = 45mm
spacing = 400mm
span = 3200mm

TRADA recommendations are to double up joists under a bath. Those joists / spans fall into the permissible ranges for imposed load not exceeding 1.5 kN/m² and dead load more than 0.25 kN/m² but not more than 0.50 kN/m². So it all boils down to the footprint / orientation of of the actual bath itself. Hopefully one of the SE's will confirm for you. All said a done, a couple of doubled upped joists will (probably) see it right .

 

[stevedo]

Hi all, thanks for responding so far.

The bath is free standing and does not have any feet to stand on. The footprint of the base is 1150mm long by 522mm wide. The bath would be position perpendicular to the joists (so spanning 3 joists) and about 600mm from the wall.

Thanks
Steve

 

[WabbitPoo]

Hi all, thanks for responding so far.

The bath is free standing and does not have any feet to stand on.

You mean it sits on its flat bottom, or that its on supports underneath?

 

[maltaron]

I would doubt whether any reinforcement is needed providing no alterations have been made to the joist arrangement. All normal domestic buildings have baths sitting on 4 feet on the floorboards and in the 70's it would be likely to be a cast iron bath. I have never known a bath to fall through the floor unless there was rot or damage to the floor. You should, however, check that you have proper floorboards and not chipboard.

 

[RonnyRaygun]

here goes

depth = 170mm
width = 45mm
spacing = 400mm
span = 3200mm

Hi all, thanks for responding so far.

The bath is free standing and does not have any feet to stand on. The footprint of the base is 1150mm long by 522mm wide. The bath would be position perpendicular to the joists (so spanning 3 joists) and about 600mm from the wall.

Thanks
Steve

Doing the calc to BS5268 and therefore allowing for 1.5kN/m^2 imposed load tells me that the joists would be overstressed...

But...unless you put a very fat bloke on every square metre of your bathroom floor, your joists are never going to see those kind of loads. They aren't going to fail so personally I wouldn't be worried.

Odd shaped bath though