Fixing Plasterboard to walls - do I need to batten?

[ChrisKingston]

Hi,

I'm trying to fix plasterboard over some old walls instead of rendering them.

Can I just screw board over old, reasonably level brickwork? If so, any recommendations for fixings?

Or do I need to batten first?

Do the answers change if:
- the board is to be tiled? (is it worth shelling out for special tileboard?)
- the board is to be tiled as a wall of a shower (is it worth shelling out for aquapanel?)

Thanks,
Chris

 

[1john]

Never seen it and would never try to screw board directly to brick work.

As for tiling on it, if its in a shower area aquapanel is the way forward, as for the other walls the board you select will depend on the size and weight of your tiles.

Battening then boarding gives you the oppertunity to get all the walls and corners true, plumb and square.

 

[Richard C]

You should not attempt to just screw the boards to the wall; you can dot & dab them but if your tiling over, you should also provide mechanical fixings (screws through the adhesive dabs) or the tile weight could pull the board off the wall.

If solid brick external walls are involved you should not use dot & dab as it can cause cold spots leading to condensation. They also tend to be damp & you can get all sorts on nasties growing in the void behind the board. In this case you should use battens with a damp membrane & possibly some insulation for good measure; you can also get insulated boards with an integral membrane which you can fix directly to the wall.

For bathrooms use Moisture Resistant plasterboard only but you should tank in wet areas (showers & around baths) if you want it to last any length of time. Use a waterproof tile backer board (Aquapanel), in wet areas, it is more expensive than PB but if you factor in the cost of tanking the PB, the cost is around the same. Don't plaster where your tiling but if you have any ½ tiled areas you intend plastering, MR PB must be primed first.

Depending on the type of walls you have, I would advise you do some more research before boarding out.

Before you do anything, read the Tiling Forum sticky & archive threads as there are several things that can trip you up regarding compatible materials & tile weights; it may prevent you making disastrous & potentially expensive mistakes.

 

[ChrisKingston]

Thanks very much for that.

All the walls are internal so I don't have to worry about damp, but some of them are to house a shower just with tiling over - of the three walls one is against studwork, one against rough brickwork and one over some very old and pretty flaky plaster. Sounds like it might be best to take this off and just work with the brick.

I'll spend the extra for suitable board for the shower bit. Would you recommend Aquapanel or Tile Backer Board, or doesn't it matter?

Also, if I use, say, Aquapanel, do I need to tank the shower area as well? Or would it be enough just to use the water-resistant materials?

 

[Richard C]

Tile backer boards come in two guises; fully waterproof (impermeable) & water resistant meaning they will absorb moisture but will not disintegrate as a result. For example; Wedi & Marmox are waterproof, Aquapanel & Hardibacker are classed as water resistant. Water resistant boards are, however, considered to give adequate protection in a domestic environment in all but wet rooms where water proof boards should be used. I use Aquapanel without tanking in wet areas which is perfectly adequate for shower/bath areas, you can tank for extra security if you wish (but it will reduce max tile weight of the backer board) or you can use a fully waterproof tile backer board. Make sure the board joints do not coincide with your tile grout lines, tape & seal the joints. Use only quality trade tiling materials of the correct type for your tiles & tile base, own brand & DIY stuff is generally crap.

 

[ChrisKingston]

Is dotting and dabbing better than battening, or can I do either? I like the idea of battening better because if you get it wrong you can start again without much damage...

Thanks very much for all the advice so far.

 

[Richard C]

Many prefer battening but both methods have their uses;

Dot & dab is quicker, slightly cheaper (no battening involved) & allows close boarding to the original wall but you also need to provide additional through fixings into the wall with tile backer board & if tiling over plasterboard; these must go through the adhesive dabs once set.

Batten fixing will take longer (to fix the battens), battens take up more space but allow you to install insulation (if required), you can isolate the boards from the wall with a barrier if there are any damp condensation problems, it’s probably easier for the inexperienced to install.

Whichever method you chose depends on individual circumstances.

 

[whoisthedaddy]

Hi all,

I have a similar dilema, I am renovating an old Victorian end terrace house which has been suffering from a little damp.

I have just removed most of the existing plaster as it was damp and almost falling off the walls.

A damp specialist is injecting a chemical damp proof over the next week or so but the question remains as to whether I dot and dab or use battens. The plasterer I use says that dot and dab will be fine but I have my doubts given the previous history of dampness. (3 of the walls are external - the front/back and side). I am worried about damp coming through the dot and dabs and penetrating the plasterboard.

I have a couple of questions:
1. Presumably the walls could also be plastered over brick with no plasterboard?
2. Is it possible to dot and dab insulated boards - I suspect the answer to this is no! if so are these the ones that are 4 times or so more expensive and you have to batten them as well - yikes?
3. Are there any shortcuts or tips for fixing the battens. I seem to remember somewhere that there are special nail in fixings that can be used which will speed up the process?

Thanks
Lee.

 

[Richard C]

Welcome to the DIYnot Forums!

Please familiarise yourself with the forum rules and enjoy the site!

6) Do not hi-jack posts. Hi-jacking is adding your query to somebody else's thread.

Read more: //www.diynot.com/forums/rules.php#ixzz1SWulD6kJ

 

[ChrisKingston]

Many thanks, I've started battening and that seems to have gone ok but on one piece of the cubicle bit I've only got a few mm for the fixing so dot and dab is the only option. What is the best material for dotting and dabbing Aquapanel? Normal 4-1 sand and cement mortar? Plasterboard adhesive?

I've bought these stainless steel hammer fixings:
http://www.screwfix.com/p/fischer-stainless-steel-hammer-fixings-8-x-60mm-pack-of-10/45692
so that they shouldn't pop the tiles. Was going through the dabs carefully and then screw rather than hammer them in - I've found that gives a better fixing anyway. I've found you can drill countersinks into Aquapanel fairly easily with a 10-12mm flat wood bit .

Do you think that'd work?

Many thanks again, especially to Richard C for his great advice once again,

Chris

 

[Richard C]

I've started battening and that seems to have gone ok but on one piece of the cubicle bit I've only got a few mm for the fixing so dot and dab is the only option. What is the best material for dotting and dabbing Aquapanel? Normal 4-1 sand and cement mortar? Plasterboard adhesive?

Plaster board adhesive is what you would normally use. You can only dot & dab Aquapanel as an initial fixing, you cannot rely on the adhesive to hold it in place; you must use mechanical fixings (through the dabs or you will crack the boards) or it will fail & the Aquapanel will fall off, particularly with the weight of tiles hung onto it. Can you explain a little more or provide a photo maybe of why you only have a few mm for fixing the panel? What size is the panel? You must mechanically secure the panel or find another way of doing it. Mortar will not work at all but powder tile adhesive might.

I've bought these stainless steel hammer fixings:
http://www.screwfix.com/p/fischer-stainless-steel-hammer-fixings-8-x-60mm-pack-of-10/45692
so that they shouldn't pop the tiles. Was going through the dabs carefully and then screw rather than hammer them in - I've found that gives a better fixing anyway. I've found you can drill countersinks into Aquapanel fairly easily with a 10-12mm flat wood bit. Do you think that'd work?

I don’t bother with stainless steel & I’ve not used hammer fixings only through, screw fixings, countersunk into the board face as you’ve done. The screw thread looks a little fine compared to screw fixings but as long as they give adequate support they should be OK; what spacing are you using for the fixings.

 

[ChrisKingston]

Hi Richard, thanks for that, I'm pushed for space in the shower alcove. I've got the Aquapanel up on battens at one side but now I've only got about 17-18mm on the otherwise between shower tray and the brick wall. So with the Aquapanel at 12mm that leaves me about 5mm, too small for a batten but should be enough for a bit of cement or adhesive. Which do you reckon I should try? Was thinking of dotting it tonight then drilling through and fixing every 200mm on two vertical strips of adhesive about 300mm apart.

I thought the hammer fixings would be good because the plug's plastic collar goes up to the head so it will be less likely to crack the Aquapanel if you screw them in tight. Can I get away with normal hammer fixings do you think? Are they waterproof enough?

Talking of fixings, I had trouble getting the proper ceramic Aquapanel screws flush with the board screwing into wooden battens. Will I get away with them 1-1.5mm proud or do I need to tale them out and countersink?

Thanks again,

Chris
Thanks again

 

[Richard C]

I'm pushed for space in the shower alcove. I've got the Aquapanel up on battens at one side but now I've only got about 17-18mm on the otherwise between shower tray and the brick wall. So with the Aquapanel at 12mm that leaves me about 5mm, too small for a batten but should be enough for a bit of cement or adhesive. Which do you reckon I should try? Was thinking of dotting it tonight then drilling through and fixing every 200mm on two vertical strips of adhesive about 300mm apart.

Still not clear are you saying you have screw fixings through into battens one side of the panel, down the centre but not enough room to get them in on the far side? Sorry not to catch on too well, but I want to understand exactly what you have, perhaps a sketch or photo?

300mm x 200mm spacing grid is OK, don’t attempt to mechanically fix until the adhesive is set (12 hours) or you could crack the board when you tighten up.

Can I get away with normal hammer fixings do you think? Are they waterproof enough?

I wouldn’t use hammer fixings on Aquapanel, big risk of cracking it; I just use these;
http://www.diy.com/diy/jsp/bq/nav.j...2150&fh_location=//catalog01/en_GB/categories<{9372015}/categories<{9372044}/categories<{9372210}/specificationsProductType=wall_plugs/specificationsSpecificProductType=plugs___screws&ecamp=aff-p9-awin-001

Talking of fixings, I had trouble getting the proper ceramic Aquapanel screws flush with the board screwing into wooden battens. Will I get away with them 1-1.5mm proud or do I need to tale them out and countersink?

You need the fixings flush before tiling, I’d countersink them. I have used Aquapanel ceramic screws in the past but, personally, I think it’s a bit OTT; I never use their tape. I always use plasterboard screws & reinforcing tape, as I also plaster I always have them.

 

[ChrisKingston]

Hi Richard, I've drawn the shower alcove here.

Untitled

• ChrisKingston
• 27 Jul 2011
• 1

The main issue is that I'm trying to get a 760mm shower tray into an alcove that is, at its narrowest, only about 810 wide. I've battened at one side and that's only left me about 5mm gap between the rough brick and where the Aquapanel needs to be.

What do you use to get Aquapanel to stick to brick: waterproof tile cement? Should I prime it with PVA first?

I wasn't going to hammer the hammer-fixings in but screw them in instead. But can you get away without paying for stainless steel ones?

Thanks,
Chris

 

[Richard C]

The main issue is that I'm trying to get a 760mm shower tray into an alcove that is, at its narrowest, only about 810 wide. I've battened at one side and that's only left me about 5mm gap between the rough brick and where the Aquapanel needs to be.

I still seem to be missing something here Assuming were talking about the bit in red being fixed to the wall, the Aquapanel at that point looks to be about 250mm or so wide why cant you get two vertical rows of fixings in there? Ideally the Aquapanel should go down past the tray but it’s not essential.

What do you use to get Aquapanel to stick to brick: waterproof tile cement? Should I prime it with PVA first?

I don’t use anything other than drywall adhesive but you cannot just rely on adhesive to fix Aquapanel, the adhesive is only used as a temporary fixing/support before adding the screws; Knauf (who make AQP) state specifically it cannot be dot & dabbed. Never prime anything in a bathroom with standard PVA, its water soluble & completely unsuitable as a primer/adhesive.

But can you get away without paying for stainless steel ones?

I don’t use them.