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Discuss DIY Guide To Installing a Wetroom. in the Bathrooms, Showers and Wetrooms area at

  1. cr0ft

    cr0ft Trusted Plumber GSR

    Hi all. We frequently get customers who are worried about having a wetroom because of problems like this: -


    This was caused by a wetroom that was installed incorrectly. If you want a wetroom but aren't sure whether you want to get a tradesperson in to do it, here's a guide to the installation procedure. If after reading it, you decide you might want to get a local tradesman in - look at our website if you live close to Lincoln!
  2. lame plumber

    lame plumber Guest

    it is a wet room, cant deny that :)
  3. cr0ft

    cr0ft Trusted Plumber GSR

    Firstly, these projects usually start by stripping the existing bathroom out. If the floor isn't completely level the joists need to be levelled in order to easily get the correct sloped when tiling the floor (this guide assumed you will be tiling the floor). There are several methods to level a floor. Perhaps the simplest method is to shim the joists either with bits of timber or with hard plastic shims. Shims used to make door frames level/plumb are very strong and can be safely used to shim joists to get them level. One shim should be placed where each screw will go through the floor into the joists.

    We also screw the shims down to the joists to stop them moving when the floor is put down.

    Check all shims are level in all directions before laying the floor.

    On a concrete floor, you will have to level the floor in other ways if it is not level. Either re-screed it or use a self levelling compound before continuing.

    A level sub-floor is essential to ensure that the small amount of water that goes through the grout onto the waterproofing sits there till it evaporates. You don't want it running out the door!

    Our installation here is on a suspended floor, so we have used an Impey Aquadec wetroom tray. For some reason, WBP Plywood comes in 18mm and 24mm thicknesses for flooring. Most wetroom trays are 21mm. By using shims on the joists you can easily adjust the flooring to get it all level.

    Once you've done all this work and cut the new floor, it should look something like this: -


    Jump about on the new floor. Walk around and check for creaks. Any creaking means the floor is not stable. Check you have screwed and supported the floor properly before continuing. Creaking now = tiles moving later = very bad!
    • Like Like x 1
    Last edited: Oct 28, 2013
  4. cr0ft

    cr0ft Trusted Plumber GSR

    Next, the walls need to be sorted. The whole room is going to be completely waterproofed with a tanking system soon, so really you can use whatever you want on the walls. We tend to use moisture resistant plasterboard on the walls. It's pretty cheap and a good strong base to tile on.

    Cutting plasterboard to fit the walls is pretty easy. You can score it on the front side with a stanley knife then break it by putting your knee into the back of the score. Finally, just cut it with the stanley knife down the back.

    Fix to the wall with plasterboard screws.

    The finished result looks something like this: -

    View attachment 15513
  5. cr0ft

    cr0ft Trusted Plumber GSR

    Now it's time to waterproof (tank) the whole room. This is probably the most important part of the wetroom installation. If this is done incorrectly the room will quickly fall apart. There are various ways to lay the tanking matting correctly though.

    We lay the floor matting first. All of the matting is fixed using a cement based tile adhesive. One 20kg bag normally fixes a 5m roll of matting.

    We make sure the floor matting goes 10cm up the walls on all sides. All rolls of matting should also overlap each other by 10cm too. All overlaps are sealed with tile adhesive. Overlaps on walls should be done such that the lower roll of matting is tucked underneath the upper roll.

    Any gaps around pipes are filled with a GOOD quality silicon sealant. Cheap stuff comes loose with time.

    Here's what it should look like when you are done: -

    View attachment 15514
  6. cr0ft

    cr0ft Trusted Plumber GSR

    Now the time-consuming bit. We're ready to tile. Spend a good bit of time planning out where each tile is going to sit to ensure there are no small cuts anywhere. Are the walls completely flat? Just because you've fitted new plasterboard to existing studwork doesn't mean they will be of course. The walls will only be as flat as the studwork behind. Are there any shaver sockets or fan vents to cut round? If so, try to make sure there's at least one grout line running across them. It will make cutting tiles round them much, much easier.

    You need to make sure you bring tiles out from the wall with tile adhesive as required to make sure the finished tiled wall is completely flat, level and plumb.

    There are lots of ways to tile. We find the quickest way is to set out the first row of tiles all the way around the room. A laser level is a brilliant investment here if you will be doing more than one room. The same door-frame shims you bought for levelling the floor are fantastic for making sure the first row of tiles is exactly level.

    Once the first row is perfectly level, all the other ones above should be, if you are using decent tiles and spacers that is! From here, just tile up the walls, constantly checking the level with your spirit level or laser level.

    These spacers are fantastic too by the way. The only spacers I have used that are exactly the same thickness from one to the other. I have tried Rubi spacers, Topps Tiles one, the lot. If anyone wants to know where to get hold of them, drop me a PM.

    Here's how things should look when you start tiling the room.

    View attachment 15515
    Last edited: Oct 28, 2013
  7. cr0ft

    cr0ft Trusted Plumber GSR

    I'm finishing tiling this at the moment so expect the next installment in a couple of days!
  8. cr0ft

    cr0ft Trusted Plumber GSR

    lol :)
  9. basildog

    basildog New Member

    The whole wet room thing in this country just does not work in my opinion !
    Timber of any kind is on the move all the time and the rubbish we now have supplied just beggars belief ?
    I used to put in a fair few laundry rooms and they are all tanked out with asphaltic before and work starts .
    You really need a concrete or brick construction to be totally sure I believe although we started using Knauf Aqua panel over 20 years ago when it was special order and the merchants thought you were mad not using plasterboard or ply in showers !
    Always ordered stone trays with upstands too as back then the number 1 reason for call backs on new housing was listed as leaking showers !
    So many wonderful very technical looking wonder materials on the market these days but start working on a 300 year old house that you can hear creaking as the weather changes you need to think again ?
    • Like Like x 1
  10. cr0ft

    cr0ft Trusted Plumber GSR

    As in my post above, I wouldn't continue past the floor stage if I could hear it creaking when I jump about on it. I wouldn't recommend anyone does to be honest. I thinks we both agree that movement in the building is a killer for any room, a wetroom, shower room or even the seal around a bath. This is the #1 cause of showers failing in new builds, the first floors just aren't strong enough to stop a shower tray flexing. Upstands are just hiding the root problem though imo. I had to rip both of our shower trays out in our new build we bought and ended up sitting the trays on the floor instead of on riser kits as the builder did. Only then did they stop leaking. This was after 6 months of the builder sending in 'plumbers' to try and fix the issue.

    I would certainly agree with you regarding a 300 year old house but to be honest 300 year old houses are very much in the minority of houses in this country. For most houses built in the last 60 years or so a wetroom is a very sensible option for persons whose mobility is starting to go. In fact, when you can't really get into a bath any more or step up to get into a shower, they quickly become the best option. I've yet to find a suspended wooden floor I can't get to stop squeaking, even if it needs cross-bracing between the joists to strengthen it first.

    Never had a callback to a leaking wetroom yet that we've fitted this way to be honest.

    Do agree with you that a concrete floor is best though!
  11. Dan

    Dan Admin

    Awesome thanks. Keep up the good work.
  12. Dan

    Dan Admin

    I've whacked a short version on the tile forum and have linked back to here. I've also stuck your contact details in the thread over at tilersforums too.
    [DLMURL=""]DIY Guide to Installing a Wetroom - Tanking & Wetrooms | Tilers Forums[/DLMURL]
    • Like Like x 2
    Last edited: Apr 3, 2017
  13. cr0ft

    cr0ft Trusted Plumber GSR

    Ok, finally. Wall tiling is done, including a little mosaic section. Note that I've left the silicon sealant work till the end, once everything else is done in the wetroom. All the dust from the construction work sticks to it as it's drying otherwise and it looks rubbish! All floor to wall joints, wall to wall joints and wall to ceiling joints should be filled with silicon sealant and not grout! The same goes for around the door architrave and window frame/sill.


    Once this is done then the next step is to tile the floor. This is where it gets difficult!


    The first thing you should do is to draw 4 lines running from the centre of the wetroom drain to the edges of the wetroom tray. These lines are the diagonal lines you can see in this picture. You can change the angle of these slightly if required to ensure that all cuts look neat.

    Depending on the wetroom tray and how you need to set out the tiles, you may also need to split the tiles with cuts along the edge of the tray. Here, we've made a cut along one edge of the wetroom tray. The reason for this is the tray slopes very steeply on that side and if we didn't cut the tile there the rest of the floor would be covered in about an inch of tile adhesive!

    The side of the tray at the bottom of the picture is on a very shallow angle so no cut is required here.

    All the additional cuts are made with a wet cutter to get them looking neat. Take care when cutting diagonal cuts on the wet cutter - it is much more likely that the tile edge will chip if you rush it. Try to cut the tile in several passes.

    Once you've divided the floor into 4 with the diagonal cuts, simply slope each part of the floor back to the tray once you are out of the tray area. The slope is about right when a spirit level placed on the surface of the tile has the edge of the bubble touching the first line from the centre.

    Tiling the wetroom tray takes a good few hours to do properly so don't rush it. From there the rest of the floor is much easier.
    • Like Like x 4
  14. GasmanxxxR1

    GasmanxxxR1 Plumber GSR

    Cant wait for the next instalment!
  15. SimonG

    SimonG Trusted Plumber

    I prefer mosaic in the actual shower area, easier to form and also the extra grout lines give you extra grip when wet. But ultimately it's the custs choice.
    • Like Like x 1
  16. phil the bucket

    phil the bucket Guest

    The pebble effect looks good also
  17. Chalked

    Chalked Plumber GSR

    Just be careful not to use mosaics on expanded foam tray formers as the point loading is too high.
    50mm x 50mm is generally the smallest you can go. Solid shower formers are ok for anything smaller than that.
  18. Alanc

    Alanc Plumber

    Croft do you have any more pics taken at the early stages, eg the wetroom tray ?. Your posts 4,5 & 6 pictures not showing.
  19. cr0ft

    cr0ft Trusted Plumber GSR

    Hi all. Sadly not, I only thought to make a guide of it once the floor was down!! Not sure what is going on with the pictures, I uploaded them through the forum and they seemed to work to start with. Will try and finish the guide off when I get time. The finished photos look nice, except the customer wanted to re-use her existing sanitaryware which spoils the look somewhat imo :(
  20. PlumbBobBob

    PlumbBobBob Guest

    don't you just hate customers when they do that?
  21. cr0ft

    cr0ft Trusted Plumber GSR


    This photo shows the wetroom floor and also my foot (less interesting). You can see the slope on the floor created by the diagonal cuts. These cuts are made using a good quality wet cutter so it doesn't chip the tiles at all. In our case, we use a Dewalt table saw wet cutter, in our opinion the best one on the market.

    Never force the tile through a wet cutter, let the blade do the work. Always ensure water is being jetted onto the part of the tile being cut for the cleanest finish.

    You also need to make sure the grout you use is suitable for the wet cut grout lines (around 1mm wide) and the normal grout lines (4-6mm usually for floors).
  22. cr0ft

    cr0ft Trusted Plumber GSR

    Fittings and fixtures can cause problems in wetrooms. Any holes drilled in the wall to fit them will damage the tanking. An assessment should be made of whether or not this is likely to be an issue. These fittings are on the opposite side of the wetroom to the shower and are all high enough that they should see no direct water spray from the shower. With this in mind we were happy to fit them with rawlplugs and screws. The alternative for fittings near the shower is to use fittings that connect with a suction cup.
  23. cr0ft

    cr0ft Trusted Plumber GSR

    And that's our wetroom story complete. Sadly the customer wanted the existing sanitaryware, mirror and shower reused. We were happy to do this but it did of course spoil the finished look. I hope this guide is useful to some and persuades any less capable DIYers to get a professional in and save money in the long term!

    For anyone in the Lincolnshire county looking for a wetroom quote, just get in touch :)
  24. PlumbBobBob

    PlumbBobBob Guest

    excellent Kieran thanks for taking the time to do this. i am going to make this a sticky and put it in the bathroom forum.
  25. lame plumber

    lame plumber Guest

    nice set of instructions for all to understand, youll be snapped up by a college soon
    • Like Like x 1
  26. Ermintrude

    Ermintrude Plumber GSR

    Wasn't everyone against a diyer doing a wet room? Top job. Excellent pictures (excluding foot)
  27. Thepipdoc

    Thepipdoc Guest

    Excellent - well written and easily understood.
  28. Thepipdoc

    Thepipdoc Guest

    Assuming some water does get through the grout, isn’t this the start of the problems that will no doubt follow? Any water that manages to get through will sit between a tile and membrane sandwich and evaporation will be virtually nil due to there being no air. Is it not possible to seal the grout so zero water passes through?

    Shame the picture isn’t viewable - I guess this is a technical issue with the site rather than anything you’ve done.
    Some of these laser levels can be many hundreds of ££’s, and some as little as a tenner
    Do you have any preferences for a decent level?

    What the name of the spacers? Again, it’s a shame the picture isn’t visible. (Mods – is there nothing you can do?)

    I see you have used an Impey Aquadec wetroom tray - is this tray flat i.e. with no fall to the drain hole? (‘scuse my ignorance but I have never fitted a level access tray before and I might be asking the bleedin obvious!) I guess it has to be given the concentric nature of the drain? Because it’s offset, a fall wouldn’t be possible - is that correct?
    If that’s the case, the only thing that is going to stop the water from spilling over the entire floor is a shower screen. If the floor is absolutely horizontal prior to tiling (as it should be) and the tiles are laid in without a fall i.e they are horizontal as well, what’s to stop the water just spilling over the rest of the bathroom floor? Sure, there’s a drain hole for the water to go into but it won’t catch all of the water – some will inevitable spill out into the main bathroom floor. Is a fall to the drain hole not essential when laying the tiles?
    I reailise that the questions I’ve raised above might come across as being confrontational – but I can assure you Cr0ft that is not my intention. I’m a curious student and just want to have a good understanding of how to do the job properly before I start.
    Thanks for taking the time to post your thread in the first place. It really is much appreciated.
  29. cr0ft

    cr0ft Trusted Plumber GSR

    Hi. No problems asking questions, that is what this guide was about. In practise, you would ensure 100% tile adhesive coverage under the tiles by using back-buttering. It is the tile adhesive that will get wet. As this is a cement based adhesive, it dries not by evaporation but by chemical reaction. It dries pretty quickly to be honest. Sorry for not making this clear. I wanted the guide to have enough info to allow someone to install a wetroom but not too much info so as to bamboozle people.

    The proof it works is in our warranty callbacks. We offer all of our customers a full 2 year warranty on all bathrooms/wetrooms. We've never once been called out to one (touch wood). Given they are a high price tag item, we certainly would be if there was a problem!

    Sealing the grout will reduce the amount of water passing through of course, as well as retain the correct grout colour and keep it clean for longer.

    Not sure what is going on with the pictures, mods - any ideas? They seem to work fine for a couple of days after I post them then they disappear.

    Our company uses Stabila LAX50 Laser Levels. It's accurate enough for precise tiling and at £100 ish a shot, pretty cheap. It comes with a telescopic pole to allow you to quickly adjust the level from near the floor to near the ceiling. Very good bit of kit.

    The spacers are UniPlug Pro Spacers. They are quite expensive but are reusable. The only thing to make sure you do is to take them out as soon as the adhesive is dry. Leave them in too long and they are hard to get out!

    There is a fall bit in across the whole wetroom tray which is why you have to cut the tiles diagonally out from the drain, to match the fall of the tray. The tray I fitted had a very steep fall on the side closest to the drain and a much shallower fall on the other side.

    You have rightly noted that you need to maintain a fall across the entire wetroom floor to make sure that any water landing on the floor goes back to the drain quickly. Sorry if I didn't make this clear in the description. This is why you continue the diagonal cut lines across the whole floor. Essentially the floor is sloped back towards the drain on each of these floor sections.

    Hope this all makes sense!
  30. Thepipdoc

    Thepipdoc Guest

    Thanks for the extensive reply - much clearer now.

    Just one other thing - how do you ensure a fall to the drain hole? Are you just using thicker adhesive the further you are from the hole and tapering it off as you get closer to it?

    Edit: just re-read your earlier reply and it would seem there is a built in fall in the tray - is this correct? If there is it doesn't come across in the picture.
    Last edited by a moderator: Nov 15, 2013
  31. cr0ft

    cr0ft Trusted Plumber GSR

    Hi. Yes and yes. As you are using a ready mixed adhesive you can layer it on thickly. To be honest I put it on the floor last thing at night first to get a rough gradient, let it dry overnight then finish off when laying the tiles. You don't need much of a fall for the water to run back quickly. Does the picture not show the fall? I think it's just the angle it's taken from. There is a pretty substantial fall on the left hand side of the tray as you look at the picture, which is why I needed the extra cut across the tiles as without it the edge of the tile would have been nearly 2 inches off the floor :)
  32. plumb_know

    plumb_know Plumber

    You mentioned earlier a technique of back buttering, what is this? Sorry I am total novice when it comes to tilling
  33. tamz

    tamz Guest

    Spreading adhesive on the back of the tile before fixing.
    Maybe best sub a tiler in if your not sure.
    • Like Like x 1
  34. plumb_know

    plumb_know Plumber

    I don't do tilling just trying to learn a bit as it's useful to know, when I do my own jobs I will sub a tiler :)
  35. Tony Robins

    Tony Robins Guest

    I've always wanted a wetroom, and now thanks to your guide, I think I shall put one in my new home. Thank you very much. :)
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