Hi all, looking for a little advice if possible.

I'm putting in a ground floor wetroom, the floor is an underfloor heated sand and cement screed with tile backer walls to 2 sides and Gypsum plaster set on the other. I have used the Bal WP1 kit to tank the shower area and entire floor of the room however, after following the kits instruction to the letter, I have found that despite trying to get the coating on as thickly as possible, that I have used a lot less than the 10 sqm of surface should have taken (4KG vs the 6-7KG on the BAL coverage guidance). I have also noticed that there are definitely thinner and thicker patches.

Should I recoat? If so when can I do this, after 24 hours?

Or should I just leave it as is, as the floor and lower walls seem to be well covered.

Cheers for any advice, wish I had found this forum before embarking on my current spec for this room, things I have read on here would have changed my approach.

Steve

I can't remember for sure but on the packaging it says when you can re-coat, I think it says you should do it within 4-8 hours of the first coat but could just be making that up. Have you looked at the instructions for re-coating?

Thanks for the quick response Colour Republic. No there seems to be no mention whatsoever of recoating times or recoating at all to be honest.

i would keep going till you run out concentrating on the lower area

i think its too weak and prefer the Mapei gum

another question would be... did you put the Bal matting down on the floor?

Thanks for your comments Chrisroe, unfortunatelty I have coated myself out of the room now so will have to wait till tommorow before I start again.

Hi Colour Republic, yes I did put the matting down on the floor and taped all of the joints with lashings of waterproof coating.

I would just give it another coat tomorrow then, I normally apply it with a trowel rather than a brush. The very nature of applying like this means you will get a thicker coat

personally i trowel on all wet tanking systems....and use fibreglass !

Colour Republic, dagger, thanks! will get the trowel out tommorow then!

You can apply another coat of this after the first coat is dry, in fact it is reccomended to apply two coats in oposite direction to the first, (ie up and down first, across second)to ensure even coverage.

Originally Posted by tommyzooom

You can apply another coat of this after the first coat is dry, in fact it is reccomended to apply two coats in oposite direction to the first, (ie up and down first, across second)to ensure even coverage.

Have you read this somewhere Tommy? I thought i'd seen this too. I mean to do with this product? I know cross applying is best practice for a lot of products not just in the tiling industry and I do it as a matter of course even if it doesn't ask for it. Sometimes it can add strength (like ply is manufactured) and sometimes it can mean you don't miss bits on an uneven surface, but I’m sure I read more technical info about this product somewhere but I'm doubting myself after looking at BAL's tech info sheet, is there a more in depth spec sheet on WP1?

http://www.bal-adhesives.co.uk/newpd...it_leaflet.pdf

CR,
I think that was the way I was shown by a bal rep on a tilers evening
it just would seem to help you not miss any bits imo
I think that Steve (zeeman)should have a look at the useful link you posted, there is a 9 step application method in it
http://www.bal-adhesives.co.uk/newpd...it_leaflet.pdf

Originally Posted by tommyzooom

I think that Steve (zeeman)should have a look at the useful link you posted, there is a 9 step application method in it
http://www.bal-adhesives.co.uk/newpd...it_leaflet.pdf

Hi tommyzoom, I have read that leaflet and scoured over the Bal sites tech docs and nowhere within them do they mention using two coats or whether or not you can put a second coat on at all, hence my question here.
Given the ruberised nature of this product my concern of putting a second coat onto the first cured coat was whether there would be sufficient adhesion between the coats not to affect the loading capability for the tiles/adhesive and grout.

I guess I'm going to give it a go anyhow but it would be nice to have something concrete to say nothing untoward will happen.

Cheers for all your posts

Steve

I use tanking membranes...lot less fussy than solution kits and no worries about getting the correct tanking thickness etc....100% water tight first go..

[ame=http://www.youtube.com/watch?v=pigKorqimGk]YouTube - Durabase wp wet room tanking membrane dura-wp[/ame]

Don't think it's a double coat, one with roller, brush or trowel

Originally Posted by zeeman1972

Hi tommyzoom, I have read that leaflet and scoured over the Bal sites tech docs and nowhere within them do they mention using two coats or whether or not you can put a second coat on at all, hence my question here.
Given the ruberised nature of this product my concern of putting a second coat onto the first cured coat was whether there would be sufficient adhesion between the coats not to affect the loading capability for the tiles/adhesive and grout.

I guess I'm going to give it a go anyhow but it would be nice to have something concrete to say nothing untoward will happen.

Cheers for all your posts




Steve

The best thing you can do is give BAL a call The reason I said the second coat should be applied before a certain amount of time is because I thought the 2 coats should cure as one ( but as I say i'm doubting myself because I can't find info to back this up). If you appply the second coat tomorrow or wait until Monday after contacting BAL will make no difference as it is supposed to cure within 24 hours


EDIT: By the way Steve is this for your place or a customers?

Try this...

Usage procedure
1. Prime all surfaces with BAL PRIME APD and allow to dry
(15-30 mins).
2. Using a suitable brush or steel float, apply
BAL WATERPROOF COATING at:
– Internal and external corners of walls/partitions
– Wall junctions with bases/upstands/columns
– At pipe penetration points/drainage channels/outlets
– Junctions of different bases/background materials
– Cracks and joints in background/base
3. Reinforce with BAL POLYESTER TAPE.
4. Apply second coat of BAL WATERPROOF COATING over
the BAL POLYESTER TAPE.
5. Using brush or steel float, apply BAL WATERPROOF
COATING to primed walls at a max. 2mm thickness.
6. Apply BAL WATERPROOF COATING to primed floor.
7. Reinforce with BAL POLYESTER MATTING (may be cut
to correct size with scissors).
If applying in heavy duty wet areas (e.g. communal showers
and industrial wet process areas) and/or where some vibration
or deflection in the base may be expected (e.g. timber bases):
8. Bed matting into coating and apply a second layer of
BAL WATERPROOF COATING over top.
9. Allow membrane to dry for min. 24 hours before tiling.
When dry, background is suitable for BAL ready-mixed (walls
only) or cementitious powder adhesives. No priming required.
NOTE: BAL WATERPROOF COATING does not provide a wearing
surface and is designed for use with tiling.

I have used the BAL and the Ardex tanking system. I got some good advice from the Ardex man ref recoating / use. Due to something to do with thixotropic fluid (think that’s what he said, he was a tanking guru and used big words) then you should only go over it again within minutes or after the hour as if you go over it again say after 5~10 minutes whilst its starting to set then the next coat will try and peel the first coat off – maybe this is what you did. Paste it over then leave it, the second coat will fill in all the thin bits if there are any. As per daggers advice I have tried brush and don’t like roller but trowel is the way to go! Put the stuff on using a cheap masonry brush (one of those big thick plastic handled things you see people paint brick walls and garden sheds with – B&Q £2 consider is disposable, tanking kills brushes), but once you have it on the wall trowel it on, it goes on smooth and compressed and you can get your tanking all the way to the ceiling and wall edges thick so you don’t naturally skimp. (the manufacturers suggest roller – looks great on a demo day but in real life how do you get to the edges with that?)

Originally Posted by Dave

I use tanking membranes...lot less fussy than solution kits and no worries about getting the correct tanking thickness etc....100% water tight first go..

Thanks for this, as I said in my first post here, had I found this forum before I would of done things differently and using a sheet membrane would of been one of the changes The other may have been not using multiformat porc tiles on the floor with an offset drain in a 1500*800 shower area, I thought I would have to marry my tile cutter as I was seeing her so much!

Also Dave, cheers for the instructions, but again they make no mention of second-coating which brings about my concerns with doing it.

Whitebeam, Agreed, that's how the info from Bal reads

CR Yes agreed, maybe a conversation with Bal on Monday would be the best bet! To be honest I'm happy with the floor especially as the matting gives the ability to ladle on two thick coats, so I'll tile that today and deal with Bal and a possible second coat to the walls tomorrow.
Yes this job is for me, though I have a loft extension to build for a client next year and they were thinking of having a wet room as an ensuite so this is valuable experience. Additionally I have my ensuite to tile too yet so guess I'll be getting more practice.


Stan001, Thanks! Yes I was definitely getting the first coat try to lift off, or indeed bead bits of rubber off, when I tried to retouch the lighter areas after a few minutes so I gave up that a course of action sharpish. I think my problem was definitely using a brush rather than a trowel, however what put me off trowelling was the ball-ache of getting it onto the trowel without covering a hawk or the like in gear. Your suggestion of brushing it on with a fencing brush and then trowelling makes perfect sense! God why didn't I think of that
I can't believe they would want to use a roller with this gear either, apart from the edge coverage issues the splatter would be something else surely, no matter how slow you moved it.

Guys, Thanks for all of your help with this, really appreciated!

Cheers,

Steve

Originally Posted by zeeman1972

Hi all, looking for a little advice if possible.

I'm putting in a ground floor wetroom, the floor is an underfloor heated sand and cement screed with tile backer walls to 2 sides and Gypsum plaster set on the other. I have used the Bal WP1 kit to tank the shower area and entire floor of the room

For future reference.........

Tanking the floor is of no benefit at all there is vertually no risk of damage to surroundings due to water ingress on a concrete floor.

As you have a concrete floor with under floor heating your first step should of been an uncoupling membrane (protects against tile cracking due to screed movement) such as dura-ci this when fixed would also of provided you with a waterproof membrane......................



..

THis is why i use membranes over solution kits....how can you be sure you have applied it 2mm thick all over....

The future of tanking within the tiling trade is to use membranes..IMHO...

Its an interesting discussion point isn’t it. I have never used the sheet method but I’m totally open minded. I can see that its less messy and you can tile faster. Don’t know ref cost comparison. My worry with sheet is if the joints are not 100% then it a fail, if the sheet is punctured then it’s a fail. Whereas with a solution covering if you put a hole through it then its probably on the wall immediately behind that’s effected only, and if that’s protected by grout / tile / no high pressure from power shower / backer board, then its probably not a fail. Whereas water could get through a hole in a sheet and then its free to go everywhere behind the sheet. All of this is just my theorising and wetdecs etc have forgotten more than I’ll ever know – so I’m happy to bow to superior knowledge. So that’s my posting just to rekick the thread ….. tanking liquid vs. tanking sheet ???? : - ) … go for it guys … tell me why I should use sheet.