Wetroom advice please

[jcoles7]

Hi All,

I am going to be starting a wetroom soon with the help of my father in law (who is a experienced builder) and am after some extra advice.

I have the following products, Impey Linear Flo 1000 x 1000, Tilesafe kit, Majestic Monaco Shower screen, Grohe Wireless High Pressure, Grohe 400mm Jumbo Rain Shower, 600mm x 600mm x 9mm Porcelain tiles.

The floor is suspended floor boards and will be replaced by Marine Ply and fully tanked using Tilesafe kit.

The walls are mainly solid and plastered (not recently plastered but in good condition) with the exception of one wall which makes up one of the shower walls which is going to be ply.

For the walls we plan to use BAL Prime APD, then BAL WP1 tanking coating and BAL Rapidset Flexible white and a BAL grout.

Is there anything wrong with this method/products ??

I have checked with Impey and all the BAL products we intend to use are compatible with the Tilesafe product.

Obviously we would not be using any tile backer boards but if I use the above tanking products I do not see the need.

Also planning to hire this type of tile saw Click Here to cut the tiles do you think this is the correct type of tool ?

Any advice appreciated.

Best Regards

Jason

 

[Richard C]

The floor is suspended floor boards and will be replaced by Marine Ply and fully tanked using Tilesafe kit.

You don’t need marine ply; WBP is made using similar waterproof adhesive but doesn’t have expensive decorative veneers which you don’t need; seal the back & edges of the ply with an SBR sealer but tank the top using your Tilesafe kit. What thickness of ply are you proposing & what size/pitch/small are your joists?

one wall which makes up one of the shower walls which is going to be ply.

Don’t use ply, it’s dimensionally unstable if subject to moisture, even from the back. It must be WBP anyway not standard ply & then you must seal it thoroughly on the back/edges & tank the tile base. By the time you’ve done all this, tile backer boards are a better bet. Use a waterproof tile backer board or a water resistant one & tank it; the difference is they will remain dimensionally stable when wet, ply (being wood) does not.

For the walls we plan to use BAL Prime APD, then BAL WP1 tanking coating and BAL Rapidset Flexible white and a BAL grout. Is there anything wrong with this method/products ??

Sounds OK on the face of it but it depends on your floor construction & the type/size of tiles you’re laying; what are they?

Obviously we would not be using any tile backer boards but if I use the above tanking products I do not see the need.

I would seriously advise you a backer board instead of the ply on the shower wall, as above.

Also planning to hire this type of tile saw Click Here to cut the tiles do you think this is the correct type of tool ?

Don’t know what size/type of tiles you’re laying but for what it’s going to cost you to hire that bit of kit for a week, you could buy a reasonable diamond wet tile cutter & manual cutter!

 

[jcoles7]

Hi Richard,

Thanks for your reply,

The tiles (as above) are 600mm x 600mm x 9mm porcelains, I will be using 22mm ply.

The tile cutter price you see is retail hire, I can get it a lot cheaper as father in law has an account.

I am not sure on the size etc of joists but will check.

The wall that I mentioned, would be ply is because it has a recess of 1.5m wide x 2m high x 14cm deep we had planned to build this out and finish in ply then tank. This also handily allows us to put the pipe work to the showerhead behind it. We could do it in block work but this will add a long drying time (6 weeks according to BAL rapidset flexi instructions).

Best Regards

Jason

 

[Richard C]

The tiles (as above) are 600mm x 600mm x 9mm porcelains, I will be using 22mm ply.

Is that both the walls & floors for the tiles?

The wall that I mentioned, would be ply is because it has a recess of 1.5m wide x 2m high x 14cm deep we had planned to build this out and finish in ply then tank. This also handily allows us to put the pipe work to the showerhead behind it. We could do it in block work but this will add a long drying time (6 weeks according to BAL rapidset flexi instructions).

You don’t need to block it, just use a cement based tile backer board instead of the ply; as I said ply is not dimensionally stable if it gets wet & if your pipe work is behind there, there is a risk of water contamination from behind

 

[jcoles7]

Hi Richard,

Yep same tiles for floor and walls, have checked with Impey and they advise that they are not an issue for the Linearflo. They actually said larger format tiles actually work better due to less likelihood of pooling but are a bit more difficult to cut/lay than mosaic.

I will do some reading up on tilebackers then, I have read that Marmox are fully waterproof but others are just water resistant. Do you know if that is correct ?

Cheers Jason

 

[Richard C]

Yep same tiles for floor and walls,

For tiles that size/weight, use cement powder adhesive for both walls & floors. Flexi only really needed over the ply floor & backer board but sometimes it’s easier to buy/use the same throughout. If you’re tanking all the walls you should be OK but any plastered walls or plasterboard must be primed to prevent reaction between the cement adhesive & gypsum plaster.

I will do some reading up on tilebackers then, I have read that Marmox are fully waterproof but others are just water resistant. Do you know if that is correct ?

Wedi & Marmox are waterproof. Aquapanel & Hardibacker are classed as water resistant because they absorb water but they will not degrade & still remain dimensionally stable. Water resistant boards are considered to give adequate protection without tanking in a domestic environment but should be tanked in wet rooms (or at least the bottom half) where water proof boards are best used used. Waterproof boards do not need full tanking, just tank the joints; yer pays yer money & takes yer choice

 

[jcoles7]

Hi Richard,

Many thanks for all the responses.

One last question then, what thickness of Marmox should I use on the recess I was thinking 20mm ??

Jason

 

[Richard C]

12.5mm (or is it 12mm) is usualy fine for walls, why do you say 20mm? what are you constructing the tile base over?

 

[jcoles7]

Hi Richard,

So for a partition wall that we will be build for our wet room we just use these instead of plasterboard and the 12.5 mm ones are thick enough ?

What about for our existing solid walls would the 6mm be thick enough ?

Best regards

Jason

 

[Richard C]

So for a partition wall that we will be build for our wet room we just use these instead of plasterboard and the 12.5 mm ones are thick enough ?

Yes but if it’s a new wall between a room containing a toilet & another habitable room (another bedroom) you also need to sound insulate the stud & use minimum Wallboard 10 on the other side to comply with B Regs.

What about for our existing solid walls would the 6mm be thick enough ?

No; 6mm is not intended for use on walls, particularly if your going to hang tiles off it.