I am going to be fitting a Mira 1400 x 800 x 40mm stone resin shower tray.Will be bedding tray down with silicone( as per M.I.),not keen on using mortar.Will be using Stixall.Existing floor is 22mm chipboard.I intend cutting out area of existing floor equivalent to footprint of shower tray and replacing wth 18mm Marine Plywood.Will be fitting noggins for support and extra strength. Existing floor joists are 190mm X 47mm.Local Builders Merchant has only 47mm X 175mm and 47mm X 200mm joists in stock. My dilemma is,should I use the smaller joist ( less cutting)or the larger joist for the noggins.The larger will have to be cut down in height from 200mm to 190mm as well as to length. Any advice appreciated.
I fitted a Mira flight in my project but went for the raised feet. I didn't like the look of the supplied trap and went for a servicable one with removable trap. Will any joists need to be cut in order for waste pipe?
Thanks for quick reply.No,joists run parallel to run of drain.Maybe need to drill a noggin.Didnt see great reviews about supplied Mira trap,decided to go for Mcalpine trap,flow rate and cleaning influenced me.Getting this one,ST90cp10-HP2.Its quite tall,ie 90 mm top to bottom.Wont be able to check drain fall until I open up rest of floor.Fingers crossed.There is another one not quite as tall,ie ST90CP10-70,it is 70 mm top to bottom,it has a lesser flow rate.So any may have to resort to this one should I run into any drain fall problems.
Those mcalpine traps are really good. I ended up buying one and quite happy with the construction, but didnt fit as quite deep i must have the larger one. I think the one 8 have fluidmaster has a flow rate of 24lpm. And it works fine. I used 40mm solvent weld pipe and all seems well, no leaks now. The rubber is much better on the macalpine trap. Had to dissasemble and refit. I siliconed it in, no leaks so far. The one that came wirh Mira is a wirqin trap.
Thanks for reply.The Mira one doesn’t have much access from the top for cleaning.There is a lot different opinions on whether to use silicone and where,when installing shower traps.Personally I maybe just silicone between the underside of the screw in section and top surface of the shower tray and leave the main seal “dry”.
Stixall is pretty strong just want to mKe sure as I dont think you'll be able to lift the tray one its stuck down.
You do not need silicone or any type of sealant with a Mcalpine shower trap, I have fitted quite a few and never had a problem.
Hmm,you’ve got me thinking now.Ive been sticking pieces of scrap wet walling to to a scrap piece of chipboard flooring using various silicone adhesives as a test.The Stixall came out best for grip,yet still remaining slightly flexible.Your right, it doesn’t release even when levered.I can see it damaging the expensive Marine ply base if attempting to remove the tray. Is removal of a shower tray not going to be problematic no matter what you bed it down with?.Mortar,ordinary silicone can get quite a grip as well.Iam sure I’ve read of someone who has removed several faulty shower trays via breaking them up with a big hammer.I have also read of faulty shower trays being lifted up off there beds of mortar,ie the mortar hasn’t stuck to the bottom of the shower tray.In my case I am leaving an access panel outside the tray,failing this,I can also access the pipe work via cutting access in kitchenette ceiling below.If however,it’s the dreaded cracked shower base scenario,this brings me back to your concern. Just when I thought I had this part of the job decided,I am going to have to rethink. Anyone used ordinary silicone like the “No Nonsense” type?.One of the aforementioned test pieces is stuck with this.Its certainly got a good grip and only comes away with a bit of leverage. Thanks for the reply.
Re shower tray. The installation instructions say it can be bedded on sand and cement (5:1 mix) or silicone sealant. I think this indicates a general multipurpose like sealant , not like and adhesive like stixall.
The macalpine dosnt mention anywhere in instructions to use silicone. But the fluid master one I used did say silicone could be used. But on the Mira shower tray instructions it does say Do not use silicone. Ok so there goes my warranty out the window
The more I think about it the more I am inclined to agree.The Mira tray I’ve got sits on its perimeter edge,the central section of the under side sits about an 1/8th inch off the floor.So what ever general purpose silicone I use to bed the tray will have to bridge this gap as well as adhere to and support the centre of the underside of the tray.More testing requd.Sigh. Honestly,of all the jobs to be done in this bathroom refurb.,Electrics,plumbing,wet-walling and joinery,this shower tray is a major PITA. Anyway thanks again for advice.
Use flexible floor tile adhesive, and prime the ply with whatever the adhesive manufacturer recommends. Have always done it like that and never a problem.
Had a look at these.They look impressive.Despite the price,I would have gone with these had I not already bought a box of Goldscrews.Thanks anyway.
The tile adhesive option seems to be popular.I queried this with Mira Tech. Dept. a couple of days ago.Their reply was “We can’t comment as we have never tested this method”. What about Jitender’s comment on being able to lift the tray back out if needed.Does tile adhesive get as strong a grip as say Stixall. BTW,what did you use,readymix or mix yourself?.
Maybe go with what the manufacture recommend. Will the tray be fitted in an alcove i.e 3 sided or just 2 sides. If an alcove then it will be impossible to lift the tray out anyway once it has been tiles.