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Using Expanding Foam to Bed Shower Tray?

Discussion in 'Plumbing and Central Heating' started by stevekane, 8 Jan 2007.

  1. stevekane

    stevekane

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    Hello everyone, I'm in the process of fitting a Stone Resin Shower Tray which has 5 adjustable legs, there is therefore a 3 inch void between the floor and the underside of the tray. The floor is a new piece of Ply and I seem to recall seeing somewhere that as an alternative to using a mortar mix you could bed the tray in using expanding foam, has anyone tried this? I have spent a bit of time trawling through the internet looking for some info without success, it seems to me to be a good idea but I'm wary of just doing it, all thoughts/ideas would be most appreciated,
    Steve.
     
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  3. Lee-King

    Lee-King

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    It has legs, why would you want to bed it on anything? Theres no need.
     
  4. Paul Barker

    Paul Barker

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    Never heard of it, no wouldn't do it. Sounds like a dodgy builder trick.
     
  5. croydoncorgi

    croydoncorgi

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    Follow the manufacturer's instructions TO THE LETTER. If the tray subsequently cracks, it will become their problem.

    Resin stone trays WITHOUT legs generally include definite instructions to bed in mortar. If it has legs, it should stand on them!
     
  6. stevekane

    stevekane

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    Hello and thanks for your replies, the first problem is that its a cheap Shower Tray and enclosure from ebay, however whilst the quality looks to be at least as good if not better than the offerings at our local discount bathroom shops the instructions are clearly translated from Chinese via Latvian and into a form of English that is not familiar to me, so a fair bit of "interpretation" is required, however I'm fairly sure it says that you have to mix up a small amount of Mortar (they suggest 1 litre ??) which is to be divided between the 5 legs, and they warn against covering the entire bottom of the tray with mortar. I think that the Mortar is really to locate the tray in position rather than for support as there is no method of fixing it back to the wall and it was under these circumstances that I thought the Foam might come into its own? but perhaps not!!
    Steve.
     
  7. Lee-King

    Lee-King

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    I've never heard of cementing the feet so the tray doesn't move, even if that is what your instructions say you should do. You shouldn't really need to and i would ignore the suggestion to do that.

    Resin trays are heavy and don't normally move around alot once in place.

    As long as you...

    - Screw the legs in nice and tight and secure the locking nuts to the tray.
    - Install the tray nice and level making sure all feet are on the floor.
    - Secure the locking nuts to the feet.

    This will prevent movement, and should be fine.

    You could always put a thickish bead of silicone on the back sides of the tray that sit against the wall. I've seen other installers using this method in the past but never done it myself. Silcone doesn't normally stick to plaster/cement rendered walls well, so maybe it wasn't silicone and was something else. But as I've said before, i don't do this - so i don't know :p

    If it's a wooden floor that the tray will be installed on, you should make sure that it's well screwed down and secure. A common problem for movement in shower trays (that i come across) is movement on the floor, where it has not been secured properly prior to installation. Obviously if it's not a wooden floor and it's concrete that you are installing your tray on, this doesn't apply to your situation. ;)
     
  8. Papion

    Papion

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    If you are sure it is translated from Chinese, then send me the chinese instruction, I could translat it to you.
     
  9. Softus

    Softus

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    Well, you I suppose you could use a substance that doesn't form a seal, sticks to your hands and every other thing it touches, is impossible to remove afterwards, and keeps on expanding, out of control, after you've walked away from it.

    Or you could just do it the normal way.
     
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  11. stevekane

    stevekane

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    Goodness your all being very helpful, many thanks, yes I understand that fixing trays with legs useing a mortar mix is unusual, but that having a Resin cast tray with legs is also unusual, in addition there are no locking nuts, the tray has 5 substansial bosses cast into the underside into which are large (perhaps 15mm) treaded Plastic bolts which are the adjustable legs, so whilst these obviasly support the tray, on their own they might not be up to the job when the shower is in use?, the instructions state that a small amount of Mortar is placed under each leg and I wonder if the job of the legs is to support the tray untill the mortar is set ?
    To the person who offered the translation, well that would have been good except I only have the English version, but many thanks anyway.

    i've now gone off the Expanding Foam idea, I thought the stickness and density of the stuff would work very well indeed, in fact I feel its probably well suited to the job, but it was the uncontrolled expansion that bothered me, it fouling the space where the trap sits etc, and of course I don't really fancy being a pioneer in useing an untried method, but I suspect some brave soul will give it a go and then we will all be useing it!
     
  12. Softus

    Softus

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    I'm having trouble making sense of what you're proposing.

    On the one hand you talk about placing mortar under a leg, and on the other you talk about providing support to supplement the legs. :confused:

    If you don't have locking nuts then you could buy some, but you'd need to be careful with the amount of force you use on a plastic thread.

    Is the floor underneath wooden? What are the feet like? Do they have holes that you can use to screw them to the floor? If not then could you drill two holes in each foot for this purpose?

    BTW, all of this is exactly why professionals don't buy stuff from eBay.
     
  13. Steady

    Steady

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    I'm fitting a bath tomorrow. It only has five feet which is a bit worrying. I think I will bed the whole bath onto three hundred weight of sand and cement.
     
  14. stevekane

    stevekane

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    Hello Softus and thanks for your reply, when you say "On the one hand you talk about placing mortar under a leg, and on the other you talk about providing support to supplement the legs" well I don't really know what I can add to this, the instructions say this is the way to go and all I'm doing is trying to poke a semi educated guess at the reasons for what seems to be a fairly unusual way of proceeding. I doubt I could locate a nut that would fit the threads on the legs and as the kit of parts was quite comprehensive I think that the maker would have provided nuts if required, as I say, although the legs are quite substantial I do wonder if they are really capable of providing sufficient support on there own hence the use of Mortar? They do not have provision for fixing down to the floor which is plywood. As to the provenance of the beast, well to be honest it actually seems to be a much more substantial piece of kit than the offerings in our local discount bathroom shops, (cheap Italian stuff I think)which were I felt rather flimsy and rattely and cost 3 times the price, so if I can overcome the little quirks I will I'm sure be very pleased with it, Steve.
     
  15. Softus

    Softus

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    Steady - stevekane is doing his best and I don't think he deserved that inadequate bit of sarcasm.

    stevekane - the bit I can't get my around is why you think mortar will strengthen the legs.

    My interpretation of your instructions is that the mortar acts to hold the feet in position - a job that the screws normally do. This will do nothing to supplement the support that the legs give to the tray.

    I'm not as worried as you are about the weight that the legs will be taking, since legs are exceedingly strong in compression, and any tendency of the tray to move sideways will be countered by the walls surrounding it - won't it?

    BTW, I didn't mean to imply that your product itself is of poor quality, but I also judge a product on the design of the installation. When I'm charging someone to fit a tray that I've supplied then I can't take extra time just because the instructions are poor, hence I only buy products that I can predict will be straightforward to fit, OR that I know I can take back to the merchant and tell them to soundly strike their suppliers' sales rep over the head with the sub-standard goods. ;)
     
  16. stevekane

    stevekane

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    Softus, its really nice of you to go to all this trouble and I appreciate it, first I should say that I really did not think you were casting aspersions on my Shower, I know that compared to a good quality product, preferably British made, it would come a poor second, but I was never the less very pleasantly surprised by the overall quality of the Chinese offering considering its price. However if I were a plumber I would hesitate about supplying one to a customer due mainly to the problems such as I'm having, and the amount of head scratching involved in fitting it.
    I can see what your saying about the legs, however unlike Bath sets which tend to have a large dia foot with fixing holes, the plastic bolts which make up the legs on our tray are just bolt heads, and to make matters worse are in fact domed. Another factor, which now occurs to me, and that I ought to have mentioned earlier, is that the tray has a "skeleton back", how to explain this,,,, well first its a Quadrant Tray, but the 2 sides which sit against the walls have no back to them, the top of the tray which is perhaps 18mm thick is all that buts against the wall, the tray does not extend down onto the floor at the rear, whilst at the front the shower tray extends down to the floor, the effect is that the shower tray sits on the floor at the front but nothing supports it at the back except the legs. There is one leg located under the corner with the other 4 legs forming a cross pattern in the centre of the tray. What I have done is to fix a "skirting" around the corner to fully support the 2 open sides of the tray and which I will bed it onto using a gap filling sealant, I though this would make a good job of both supporting and fixing it in position, and I suppose that in view of all this, any additional support is probably not required,,,, except that the maker does say dollop a small amount of mortar under each leg,,,,and given that the legs are not that substantial, I really would like to get just a little additional support in the centre of the tray. Now to float off another idea, the void between the underside of the tray and the Plywood Floor is approx 2 3/4 inches (I'm not really a metric person, would that be about 7cm?) and I wonder if I might fix to the floor a couple of pieces of timber approx 2 1/2 inches thick, on top of which I could then apply a few big blobs of gap filling sealant, I would then be bedding the tray in on the two sides and across the middle with the legs just acting as the stops keeping the levels until the whole lot sets, from your experience do you think this a viable idea?, I believe that bedding trays in on Sealant is not uncommon?
    Once again, many thanks for your help,
    Steve.
     
  17. Nige F

    Nige F

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    Yeah, but what mix ratio :?: :LOL:
     
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