What's involved with reinforcing a floor?

aliasojo

I'm having second thoughts about the bath I was buying and I might be considering a large Carronite one instead. One bathroom site states that the floor may need re-inforced to support the extra weight of the Carronite bath, especially since it's fairly big at 1800 x 800.

I've just laid a new floor and it's glued and screwed to within an inch of it's life so I'm not up for ripping it up again. :rolleyes:

So what's involved with floor reinforcing...is it something that you do under the floor or over?

lagi

It will definitely be under the floorboards, normally doubling up the joists. Do you know what depth they are? and how far apart they are spaced? Somebody might know a formula for calculating.

aliasojo

The joists measure 190mm deep and between 45/50mm thick. They are spaced at 16" centres.

Cknocker

One more bit of info required, whats the length of the span of the bath?

Also What way do the joist run in relation to the bath? Where is the bath in relation to the bearing of the joists. i.e ois it near the end or the centre?

Is the bath open sided or covered in?

ormus

if the bath is covered in then using spreaders on the feet will help to spread the load. i doubt you will have any problems if you use some spread plates.

aliasojo

Cknocker wrote: »

One more bit of info required, whats the length of the span of the bath?

Also What way do the joist run in relation to the bath? Where is the bath in relation to the bearing of the joists. i.e ois it near the end or the centre?

Is the bath open sided or covered in?

Bath will run across the joists, not run the same way as them.

It will be nearer the centre than the end of the joists...there is a bedroom either side of the bathroom and the joist end is halfway under the bedroom joined to a triple joist going across in the other direction.

The bath will have a front panel.

Span of the bath? Do you mean the length? If so, 1800mm. If not, sorry not sure what you mean.

Cknocker

Sorry, i'm going nuts, i meant the span of the joist. I assume there was a bath in the location before?

aliasojo

Span of the joist? Do you mean the length of the whole thing?

If so, I'd guess at 6 or 7 mtrs long.

Bedroom (3mtrs) / Bathroom (2 mtrs) / Some of next bedroom (so maybe 1 or 2 mtrs absolute tops).

So around 6 or 7 mtrs from one end to where it joins to triple joist by hanger.

Yes, original (smaller) bath was in the same spot.

Cknocker

Is the joist sitting on a supporting wall underneath? Possibly with two joist sitting on it. Modern standards recommend no more than 4.2m for a 195x47 joist?

aliasojo

Yes, there is a supporting wall. It's situated under the wall between bedroom 1 on the left (the 3 mtr one mentioned above) and bathroom. There are 5 joists in the bathroom floor and all run across this wall.

I can't make out at this point whether the joists are actually in one length or not.

So it's either:

Bedroom 1 / Bathroom / Half of next bedroom

Long joists spanning 6 or 7 mtrs ......crossing supporting wall underneath at point where bedroom 1 ends and bathroom starts....then joining to triple joists.

OR

3mtr joists under bedroom 1 ending at supporting wall then bathroom joists start from this point.......then joining to triple joist.

Thanks for taking the time btw.

Cknocker

I assume that the wall is of masonry construction, if it is and the joists are actually bearing on it, I would say you don't need to worry about reinforcing the floor, as it will be more than capable of taking the extra weight, as the bath will be sitting near the bearing point.

If you want to make doubly sure, sit the bath on longitudianal spreaders, i.e. 2 pieces of 4x2 running the length of the bath, this will spread the load across the five joists.