WATERPROOF PRIMER NEEDED ?

[DAJ]

I am about to tile bathroom walls, floor and shower enclosure with porcelain tiles. I have fitted 12mm ply boarding to the floorboards but I'm unsure as to which primer, if any to use on the walls and floor.
Two faces of the shower enclosure are made from 18mm sterling board the others plastered brickwork wall. The walls around the bath are of plasterboard (unplastered). I now know that there is a water resistant plasterboard available , tooooooo late

I have primed all the walls with a pva based unibond product but feel I should cover this with a more water resistant product in the shower enclosure and around the bath.
I know I could apply a tanking membrane but feel this is excessive and costly. Would an ordinary oil based wood primer applied to the shower area and around the bath be enough. also, do I need to prime the floor.

I am using a flexible adhesive for the floor but do I need to use a flexible adhesive on the walls.

Thanks !

 

[gcol]

//www.diynot.com/forums/viewtopic.php?t=86508
Be careful how you give advice to this fool.

 

[DAJ]

//www.diynot.com/forums/viewtopic.php?t=86508
Be careful how you give advice to this fool.

You must spend your entire life on this site gcol, have you no friends or family to talk to mate ?

 

[gcol]

My entire life?.... Nope, but when I have a moment spare throughout the day I'll come on here - never too far from a pc you see.
Family and friends? Yes I have a wife and daughter and plenty of friends thanks. The daughter is sleeping (she's 3) and the wife is doing a bit of ironing. I'm now going to read in the sunshine with a can of lager.
Anything else you'd like to know?

 

[Jasonb]

You will have to find an adhesive that will work on the surfaces you have already coated, can't say what as all the ones I use are not compatible with PVA based products.

Ditch the sterlin board, its way too unstable and affected by moisture, Gcol's sticky will give you an idea of what to use in its place

Jason

 

[gcol]

I've told him all this Jason but he won't read, or won't take on board the information in the sticky. Don't waste your time.

 

[DAJ]

You will have to find an adhesive that will work on the surfaces you have already coated, can't say what as all the ones I use are not compatible with PVA based products.

Ditch the sterlin board, its way too unstable and affected by moisture, Gcol's sticky will give you an idea of what to use in its place

Jason

Cheers Jason. The adhesive, according to the manager at Topps Tiles, is compatable with PVA products. The point I was making, do you think an additional primer should be used in the wet areas.
With regard to the sterlin board walls, it is already fitted after being recommended by a local builder (opinions differ I guess). He said it's the best to use as it's waterproof (used for flat roofs, dormer windows etc.) and the stats are higher than marine ply.

On the subject of gcol's sticky, I followed his advice (thanks gcol !) and used the 12mm ply and the PVA. He didn't give an alternative to PVA in wet areas though (other than the extreme tanking treatment).

Thanks for the help Jason, any further help would be appreciated.

 

[gcol]

On the subject of gcol's sticky, I followed his advice (thanks gcol !) and used the 12mm ply and the PVA. He didn't give an alternative to PVA in wet areas though (other than the extreme tanking treatment).

Quote from the sticky:
Primers and tanking
"What primer do I use? You may or may not have heard some mixed opinions regarding PVA as a tiling primer. I don’t intend to get into the “ins and outs” of it here but suffice to say, I have no problem with using PVA as a primer for tiles in a non water situation. For showers and bath areas (I mean immediately around a bath and not the rest of the bathroom) I wouldn’t use it. ALWAYS read the instructions for the adhesive and follow them."

Meaning that if the manufacturer specifies a primer, use that primer.

 

[Jasonb]

Unibond only make one adhesive specifically for porcelain tiles, not sure if it is flexible but you MUST use a flexible adhesive on all the boarded surfaces.

Well I have never seen LLoyds register approved sterlin board and I doubt it will perform anywhere near as well an Anchor brand MArine Ply.

The problem is that the ahhesives used to make the boards are waterproof (refered to as WBP) but the actual timber is not so when it gets wet it will swell and being made from flakes of softwood will not resist rot like the hardwood layers in marine ply.

Jason

 

[DAJ]

On the subject of gcol's sticky, I followed his advice (thanks gcol !) and used the 12mm ply and the PVA. He didn't give an alternative to PVA in wet areas though (other than the extreme tanking treatment).

Quote from the sticky:
Primers and tanking
"What primer do I use? You may or may not have heard some mixed opinions regarding PVA as a tiling primer. I don’t intend to get into the “ins and outs” of it here but suffice to say, I have no problem with using PVA as a primer for tiles in a non water situation. For showers and bath areas (I mean immediately around a bath and not the rest of the bathroom) I wouldn’t use it. ALWAYS read the instructions for the adhesive and follow them."

Meaning that if the manufacturer specifies a primer, use that primer.

Fair comment gcol, I'll read "what it say's on the tin", defeats the object of a forum though.

Just for the record gcol (relating to your sticky), I phoned BAL for advice and was told that I should have used 15mm minimum and not 12mm ply which should have been screwed every 300mm. BAL also told me that most manufacturers, including BAL, never advise the use of PVA products as a tile primer in wet or non-water situations. Apparently the molecular structure of PVA is such that upon contact with most tile adhesives PVA may revoke back to it's original consistency thus rendering the primer useless. For the adhesive they recommend Fast-Flex (mixed with bottled solution/fixer) and in the wet areas around the bath and shower enclosure, WP1 tanking solution.

BAL damned the use of sterlin board as did Jason and, at first, suggested ripping it all out. Jason was spot on. But they've now suggested that, rather than remove the sterlin boards, plumbing, fittings, drainage etc. etc. etc., I simply cover all the sterlin board with plasterboard and fix the tiles to that.

Thanks gcol, Jason and BAL.

 

[gcol]

15mm is overkill when overboarding. BAL who make and sell their primer are hardly going to recommend the use of PVA now are they? I specifically said to follow the manufacturer's instructions regarding primers etc so if BAL recommend their own primer on their bags of adhesive then you should use it.
If you look back at your last post I posted a link to, you'll see I told you not to use Sterling board way back then.
Did you ask them if you could tank directly over the Sterling board?

 

[DAJ]

15mm is overkill when overboarding. BAL who make and sell their primer are hardly going to recommend the use of PVA now are they? I specifically said to follow the manufacturer's instructions regarding primers etc so if BAL recommend their own primer on their bags of adhesive then you should use it.
If you look back at your last post I posted a link to, you'll see I told you not to use Sterling board way back then.
Did you ask them if you could tank directly over the Sterling board?

GOOD point. That'd save a lot of time.

 

[Jasonb]

If you are going to overboard the sterlin with plasterboard and the tray is in place or you have to fit a screen between two walls make sure that the screen will still fit as the range of adjustment can be quite small.

Jason

 

[DAJ]

15mm is overkill when overboarding. BAL who make and sell their primer are hardly going to recommend the use of PVA now are they? I specifically said to follow the manufacturer's instructions regarding primers etc so if BAL recommend their own primer on their bags of adhesive then you should use it.
If you look back at your last post I posted a link to, you'll see I told you not to use Sterling board way back then.
Did you ask them if you could tank directly over the Sterling board?

I was refering to fitting sterlin board to the FLOOR gcol. The shower enclosure had already been constructed when I asked the question. I took your advice and put 12mm ply down (thanks).
I should have posed the question regarding the enclosure long ago. You (gcol and Jason) would have advised against sterlin board and I would have listerned, learnt and saved a lot of time.

With regard to BAL, they advised AGAINST any primer, including their own. They said I could have tiled direct to plasterboard, a ply enclosure and plaster.

 

[gcol]

Ah ok, keep us informed and it's always nice to see a few pics when you've finished.