Injecting support for a shower tray

Hi - my plumber has just installed a shower tray, and it would be very difficult to remove. However, the tray is not very well supported., and flexes when stood on. It was supported with mortar, but only in a few areas (for some reason), and these blobs of mortar have not stuck in place so they can be pushed around with a stick...

However, I can get access with a hose to the cavity under the fibreglass tray. Can anyone suggest some sort of filler I can pump into the void, which will set hard enough to support the tray well? I'm concerned standard expanding foram may not be up to the job...

Cheers,

Ben

Reply to
barkerben
Loading thread data ...

The correct solution would be to ask the plumber to come back and fit the tray properly. If it's difficult to remove, that's his problem. If he breaks it getting it out, that's also his problem.

It should be bedded according to the manufacturer's instructions and that usually involves support for the whole base. If you do something now that turns out to be unsatisfactory and the tray cracks in a few weeks or months you will have no real come-back.

Reply to
Andy Hall

Unfortunately the manufactures instructions were in no language known to mankind - multiple translations had been involved I think. If it is damaged, it becomes my problem, as it was very hard to source, and will be extremely hard to replace.

I had assumed they would do the following however:

Put tray upside down Fill with mortar Place pedestal on top Wait to dry Up end whole lot Done

Hence the whole cavity is filled. It seems this was not done...It is difficult, 'cos my plumber is very nice and claims it will be fine, but I'm don't really share his confidence...

Ben

Reply to
barkerben

Did the plumber supply the tray? If he did, the instructions and sourcing a replacement are still his problem.

Owain

Reply to
Owain

Standard expanding foam will be more than strong enough if the void is completely filled. However, the problem will be getting the right amount in. It continues to expand for about 20 mins and if too much is put in place with no expansion outlet it will be more than strong enough to push a ceramic shower tray up out of its mountings. You would have to do it in installments putting a layer of foam filling the space vertically but not horizontally, leaving it to set (and expand horizontally, and repeating the process. Simply squirting a pile of foam through a hole will almost certainly lead to either not enough foam going in or too much with the consequent risk of damage.

Reply to
Peter Parry

which a hose can be put. I was thinking that I could put an extension hose on my foam cylinder, then fill from the back of the shower tray, working forwards towards my hole. Hopefully the stuff is runny enough that it will fill sideways if it finds above is blocked, with the eventual release point being the hole I have poked my hose through...?

Reply to
barkerben

Oh dear.

The normal way is to lay a bed of relatively dry mortar over the whole area and to bed the tray down onto it

Unfortunately being nice is going to address the issue. Perhaps find a similar looking tray and look at the instructions for that/?

Reply to
Andy Hall

================================== I don't think this would be a good way to get a full mortar base as the mortar would be so heavy that it would probably fall out when you turned the tray the right way up.

On the other hand this would be a good way of filling the entire cavity (allowing space for necessary access holes) with expanding foam since you could over-fill and slice off the surplus when fully cured. It would be best to leave the foam slightly 'proud' if you choose this method.

Cic.

Reply to
Cicero

There are low expansion foams available.

For example

I haven't tried it myself but help might avoid an oozing mess or expansion damage!

HTH

Steve

Reply to
Steve

It will roughly double in size, mostly after it's too stiff to be forced out of the hole. You'd probably end up with a domed bottomed shower tray. (Do have a digital camera handy so you can put the pictures up on a website;-)

I think you can do this with expanding foam, but you are going to need better access and visibility underneath to control the quantity.

Have a read of

formatting link

Reply to
Andrew Gabriel

I suppose the only way of ensuring full support then would be to use something extremely fluid and non-expanding. Seal around the hose entry point and simply fill up the void, then wait for it to go off. Any ideas of such a material? We use something like that for sealing the bottom of on-street equipment, but unsure what it is made of!

Reply to
barkerben

Usually with fibreglass trays they have support brackets or feet that carry the tray and take the strain. They do not eliminate all movement however.

One usually uses mortar for stone resin trays - these are preformed concrete trays with a resin cap - a totally different proposition from what you have fitted.

Dabs of foam under the most bouncy bits would probably do what you want quite nicely. Just take care not to go mad with the filling!

Reply to
John Rumm

Who sourced the tray?

If the plumber's choice he will need to fix at HIS expense.

Reply to
Gel

I sourced it - the only one I could find in that size. However, if it was not fitted correctly, then I would still seem to have somne comeback. Hmmm...

Reply to
barkerben

That was certainly our experience when we had an acrylic liner fitted into a steel bath. The fitter used very sparse dabs of foam in the bottom of the old bath, leaving plenty of room for the foam to expand sideways. He filled the bath with water until the foam had set (and if doing something similar with a shower tray, I'd suggest weighting it down with boards and blocks).

When we started to use the bath, it felt completely firm and rigid. Over the first few weeks we found a few isolated spots where it made a crunchy noise if someone put their whole weight on the ball of one foot (though we still couldn't feel any movement), but once those spots had been 'stress relieved', there was no more sound. The bath remained completely firm for over 15 years until we moved.

Reply to
Ian White

That's what it says on the tin, I don't believe it. Quadruple from the inital size a few seconds after leaving the tube is more like it, at least with the DIY stuff.

There is in effect a double expansion, an inital one lasting say 30s to a minute, from when the stuff leaves the tube. This inital expansion is roughly double from the size a few seconds after leaving tube. Then a much slower and longer one (20 mins or so) which doubles the volume again.

Also be aware that the stuff sticks to anything and everything, instantly. Vegetable oil is a good release/cleaning agent. I'll certainly cover my hands with veg oil next time I ever use the stuff.

Or get one of the foams that just does the initial 30s - 1min x2 expansion. The window fitters last years had something that did just that, far easier to judge how much to squirt in. Another thought is to use some form of mould to force the foam up to the base of the tray but have a gap for over expansion and do it in stages working forward, if you have the access of course. For a mould I'm thinking of some thin card rolled into a

4 to 6" dia cylinder.
Reply to
Dave Liquorice

I had been thinking of getting a canister and putting a section of hose on the front, approx 1m long, so that I could deposit the foam in the correct places. The question is whether the pressure would be enough for this extension tube to work...

Reply to
barkerben

That really depends on the quality of the shower tray. We have a Showerlux tray in one bathroom. It was bought as a temporary measure, the other bathrooms have ceramic shower trays, and all of the previous showers that I've fitted have been ceramic. I'd say that the Showerlux is as rigid as the others, however it does have a substantial steel subframe and I took care to ensure that every foot was correctly adjusted.

I suspect in this case that either the shower tray is a cheapy or the plumber simply didn't install it correctly. My approach would not be to piss about with foam but to get the plumber back and tell him to fix it

- at his cost.

Reply to
Steve Firth

Unfortunately not - it is a non-standard size, so I had to source it. The instructions leave something to be desired - like english that makes sense :-)

Reply to
barkerben

If you can't get him to do that and he sounds a bit of a cow poke, then there is a "mix" for bedding down fibre glass trays like wot I did last year, costs a small fortune balmix or BAL something or other made by the people who make BAL Grout takes a little while to go off but its bloody solid. You might be able to inject some of that in the cavities and it doesn't expand like the foam does.

Its like a strong rubber when set....

Reply to
tony sayer

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.