Bowed Stone Resin Shower Trays

[DIY Bobster]

I am currently doing a bathroom renovation and decided on fitting a Merlyn Level 25 stone resin shower tray. In the instructions, the first thing they get you to do is check that there isn't an excessive bow on all four sides. They do this by getting you to prop up the tray on four blocks of wood and then using 3mm shims in the corners, run a level across each side and see if there is a "rock" in the level. In other words, if the middle of the tray edge bows upwards by more than 3mm. So obviously there is a 3mm tolerance on these trays, so some bowing is expected.

Tray numbers 1 and 2 failed the rock test and were bowing upwards, but only marginally (approx 1-2mm). Merlyn, to be fair to them, were happy to send out replacements. Tray number 3 didn't fail the rock test, because the bow was in a downwards direction (away from the ceiling) and was significant (about 10mm). Now if I was following the instructions to the letter, this wouldn't fail the rock test, so if this was the first tray I had received I might not have questioned it. However, Merlyn said more than a 3mm bow in either direction means it needs replacing. Tray number 4 came and same problem as tray number 3, but only a 7mm downwards bow.

Interestingly, I had a chat with the courier who implied this was quite common (and apparently even more of a problem with Merlyn Truestone range). One of the things that the courier also said was that even though the trays are supposed to be stored flat, when they get packed into the van they are stored upright placing all of the weight onto one of the edges. In addition to this, they can sometimes be loaded this way the night before delivery, so can be upright for 12-24 hours on occasion.

So many questions regarding this:

• Is this a problem with all stone resin trays, or just low profile ones
• Is this problem with all brands of stone resin tray, or specific to the Merlyn brand?
• Would storing the tray upright for 24 hours really be enough to create a bow on what I assume is a solid product?
• What experience (good or bad) have people had with other similar trays and manufacturers

I am looking at a plan B in case Tray number 5 has the same issue, but the whole floor and waste position has been geared around this tray and I don't want to rip it up and reposition the waste if I can help it (although I would rather do that than live with a defective tray!). I have heard good things about the Mira Flight Level tray, but I don't think the waste will fit around my joist configuration (need to check).

Rant over, thanks for reading!

 

[drives]

I had a QX one which bowed as well. Caused me some problems trying to install a frameless shower enclosure as the side panel wouldn't sit right, albeit I was told by the bathroom shop that I'd be lucky to find one that was flat. Seems from my experience to be par for the course....

 

[lostinthelight]

You must be very patient , I would have wanted a refund after the second failure.

 

[DIY Bobster]

I had a QX one which bowed as well. Caused me some problems trying to install a frameless shower enclosure as the side panel wouldn't sit right, albeit I was told by the bathroom shop that I'd be lucky to find one that was flat. Seems from my experience to be par for the course....

I did try and ask Merlyn what the issue was if I fitted the bowed ones. In my head, the only issue (assuming water still drained the right way) was fitting the shower screen bar and having to fill in big gaps with silicone where the frame meets the tray. Also, potentially having to profile the bottom tiles to the curve of the tray could be an issue. But Merlyn said it could be a sign of something more fundamental and there might be a risk of it failing.

Do you think the problem is only with the low profile ones (25mm) ?

 

[DIY Bobster]

Just a quick update. Merlyn delivered tray #5, and I was assured that the courier had delivered this one flat. Did the level tests again and it was the same issue as tray #3 and #4, a 7mm downwards bow (4mm after you account for the 3mm spacers). When I pointed this out to Merlyn they came back and said this is fine and copied and pasted the original instructions that points out that the tray is only defective if the level "rocks" i.e. the bow is more than 3mm in the upwards direction. This suggests that they are now rowing back on their original advice and that actually, trays #3, #4, and #5 are all OK to fit.

So if anyone needs a tray I have three going spare, although they have been stored up ended so are probably more like a 700 x 1400 size than the original 800 x 1200