Homelux membrane & PVA mixed with adhesive

[Matt 87]

I am a plumber by trade but am tiling my friends bathroom this weekend and wanted to get it right.

1. We asked Topps tiles for a membrane to seal the walls, I have only seen a product that you paint on applied before but they recommended Homelux membrane so we have that.

It says on the instructions to use a 4mm notched trowel to apply adhesive to stick the membrane to the wall, we wanted to test out a small section before I left earlier but only had a normal flat edged trowel with no notches in it, so the surface of the adhesive is smooth and probably 2-3mm thick, will this mean the membrane we have applied will not support the tiles?
They are a 33 x 33 ceramic tile.

2. I have had a quick look around on the tiling forum and PVA seems to be a big no no, does that include mixing a little into the adhesive, as the walls are solid but the thinking we had was mixing a little PVA to the adhesive will give better adhesion to the wall.


Walls are plaster onto breeze block and we are using a BAL powder adhesive.

Many Thanks Matt.

 

[tictic]

for the membrane you should be ok,as when you apply it to the ribb of adhesive,you then use the smooth side of the serator or use a squeegy float to smooth it.

as for the pva thats a no..no..you dont need this as the bagged addy will ..do the job for you mate..

only thing i would tell you to do is prime the plaster first with an acrylic primer or a sbr just follow m.i. for ratio mate...by doing this(prime) you will stop any reaction between the finish plaster and the cement based adhesive

primer...
primer g from mapei
apd or sbr from bal..if your using bal bagged addy then use their primer..

member your weight per m2 onto plaster 20kg per m2 including addy grout this comes in at about 3-4kg per m2.

 

[Richard C]

I’ve just staggered in from the garden to “check in” before bed after a very long day of not doing much else except sunning & drinking; no point in doing much else in this glorious weather Tictic’s advice is spot on the mark & for this late on Saturday night mate, it’s a credit to ya

 

[tictic]

...ya lucky sh$t...its ****shhhhing down up ere...an am bored..lol... .....anyone one for a DISCUSSION...???...

 

[Matt 87]

Cheers guys, well got there this morning and the Homelux matting had not stuck at all so didnt bother with it in the end.

Bought some Bal APD on the way and just sealed the walls using that.

I was not so conviced that hanging tiles on this matting stuff was a good idea as the matting adhesion to the wall must be spot to support the tiles weight, what would u recommend using to stick it to the wall with?

Topps Tiles salesman said the paint tanking sealant is about £75 (didnt say for how much but were doing a 6m2 area) is that around what you usually pay for this stuff?

A bit ****ed of with Topps we went with this stuff over the paint now or even APD!

 

[Richard C]

Cheers guys, well got there this morning and the Homelux matting had not stuck at all so didnt bother with it in the end.

Did you follow the manufacturers instructions? It must be fixed with powder cement adhesive (flexible if tiling over boards); tub ready mix is not suitable. Gypsum plaster & boards must be primed with APD to avoid a reaction between the plaster & cements in the addy. Mixing PVA with it is a definite no & if that’s what you did, that's why it hasn’t worked.

Bought some Bal APD on the way and just sealed the walls using that.

Just using APD will not replace the need for tanking.

I was not so conviced that hanging tiles on this matting stuff was a good idea as the matting adhesion to the wall must be spot to support the tiles weight, what would u recommend using to stick it to the wall with?

Tile weight over plaster is restricted to 20 kg/sqm regardless of anny tanking you put over it; bare boards or render increases this to 32kg/sqm + which is more than enough in most cases.

 

[jctilingservices]

been offfline for a few days now and just had a reaqd through this topic, the information given to you by TicTic and Richard is 100% spot on mate, nothing i can add to that has not been mentioned

 

[Matt 87]

It was a combination of things that made it not stick, I was using Bal Wall and floor powder but stupidly added a little pva, the thickness of it was probably not enough either as I said in the original post I had only used a normal trowel so didn't have any ridges in it.

We did not tank in the end (I know this is stupid but learn from your mistakes). It is a shower over bath so hopefully will not as be as a impact area as a normal shower area.

What do you usually use for tanking, the paintable stuff or a membrane similar to Homelux?

With the walls being concrete breeze blocks the minor imperfections can show. How would you get a nice square and flat surface, plaster skim, board over as I appreciate you can loose a few mm in the adhesive but not a huge amount.

Many thanks for your help though, unfortunately it will have to be taken on board for future work.

 

[Richard C]

but stupidly added a little pva,

Well there ya go.

What do you usually use for tanking, the paintable stuff or a membrane similar to Homelux?

A membrane system has a big advantage over a “paint on” system for most pro tillers as they probably won't have the time built into their price to spread the job over 2/3 days; time is money! IMO, both are equally as good if done correctly but most DIY’ers will get on far better with a “paint on” system where time is not critical.

With the walls being concrete breeze blocks the minor imperfections can show. How would you get a nice square and flat surface, plaster skim, board over as I appreciate you can loose a few mm in the adhesive but not a huge amount.

If you’ve bare blocks, don’t start plastering it; after filling out the worst, just tank & tile straight over it; with CORRECT prep, it’s the best way to go.

 

[Matt 87]

Would you recommend the BAL training courses at all?

 

[bathstyle]

Rapidsetting cement based is ideal for matting, both for Homelux and kerdi matting although Kerdi Coll adhesive should be used where sheets overlap. The matting by both these manufacturers will always peel off fairly easily but this is normal, if you peel the paper face off plasterboard it'll come off easily and we all know how much weight that will hold