Construction of wet room floor, sequence of events question ?

[honeymonster]

Hi all,
I have been reading up on all the good advice and guides here on this forum but still wanted to do a final check with peoples opinions and expertise if I could?

I have put aquapanel up on the walls that will form the corner where the shower is based. The rest has WBP ply over the basins and green plasterboard on the walls up to the door.

I have cut 18mm WBP ply for the floor which now replaces the old floorboards.
QUESTION - Does the underside and edges need sealing ? I heard Acrylic paint should be used,if so is there any particular type or just that available through screwfix?

I was then planning on fixing this to the joists at 20mm intervals with stainless screws and putting noggings along the joints.

On this goes the 19mm former which takes up most of the room. The remaining area I want to take up using Marmox boards fixed to the plywood using dunlop tile on wood adhesive. I will tape and seal the joints with PCI Lastogum.

As I want to lay UFH over the former and the rest of the floor I will use SPF to cover the mat on the former and then SLC on the rest of the floor.

On this I will completely tank the floor and the 2 walls that form the corner where the shower is as well as about 8 inches up all the way around the walls using PCI Lastogum, and DUNLOP tanking kit (apparently made in the same BAL factory).

SO....How does this plan measure up?

My first issue is sealing the PLY floor underside and edges. I now can't find the post that said this was required, and wonder why this would be required?


All advice and comments will be very welcomed. I will try and take some pictures of the project as it goes along.


Many thanks in anticipation,

Gary

 

[kendo1]

'My first issue is sealing the PLY floor underside and edges. I now can't find the post that said this was required, and wonder why this would be required?'

It's to stop moisture entering from below. Don't seal the top as the adhesive won't stick.

 

[Mike]

i would overboard the ply with a minimum 6mm cement board laid on spf and screwed every 150mm as ply is not ideal to tile on and that dunlop adhesive sounds a bit gimmicky, for safety i'd use one of the popular brands, bal or mapei for example

 

[honeymonster]

Do I need to seal under even if it's on a first floor?
what paint would people recommend, was looking at some from screwfix.

Re the ply I was going to put marmox onto ply with the tile on wood adhesive. Then ufh etc.....

 

[honeymonster]

Do I need to tape and seal the joints on the Marmox floor sheets if they are going to have UFH on top and then SLC and then tanking?
I assume the tanking should just go on the very top level. i.e. go under the tile adhesive?

Cheers,
Gary

 

[White Room]

I tape the joints and wipe some adhesive in but leave a small gap between each sheet to allow for any expansion..

 

[bugs183]

You won't go wrong with any of the Dunlop, Bal or Mapei products, everyone has their favorites here, but still get the same finish, just don't be tempted to pop down to B&Q and buy any of the Unibond sludge if you start running out of adhesive or grout!!!

This is a wetroom and it needs to be built properly and using materials fit for the job.

I have used the Dunlop adhesives alot, and they are made under the same company (Norcross) as Bal and are every bit as good as the Bal products, you actual can't tell the difference. But i have found Mapei to be a far superior manufacturer so i'm dealing with them more and more. The Bal/Dunlop tanking system isn't a patch on the Mapei Aquadefence, Mapeband system, as its dries quicker, and above all sticks much better.

 

[honeymonster]

So should I tank the joints in the boards under the ufh and slc? Surely if the slc is tanked over the top then no water should get through?

I know ill probably have to talk to basf our dunlop but do people think lastogum could be used side by side with dunlop?

Thanks for advice I'll get around to posting some pics soon I hope.

cheers,gary

 

[jay]

Tank the lot not just the joints

 

[honeymonster]

All,The tray and UFH heating are now down with the SLC poured over the cables to bring the floor and tray level.I'm now moving onto the tanking and must admit I'm a bit stuck regarding jointing tape. The PCI pack only gives 10m of tape.I want to tape the floor/wall and shower tray joints as directed. However if I am to tank the aquapanel joints that have been joined using aquapanel tape and SPF and the fixings also then I will need more jointing tape....?Some have suggested using glass fibre sheets as stocked by halfords? Are these resonable, or should I fork out for proper tape, and is wickes stuff suitable?Cheers guysGary

 

[Dan]

I wouldn't use glass fibre sheets they might be too rigid long-term.

All the manufacturers do the jointing tape though so shop around a lot. Some do big square sheets of the stuff that you can cut it up if you can find some. Works out a bit cheaper if I remember rightly.

 

[honeymonster]

I need some more taking compound anyway so will probably opt for rib of dunlop stuff and an extra role of tape. Probably overkill but don't want to risk a leak.....