Can I tile directly onto Thistle Bonding Plaster

chriselevate · 1 Jul 2009

Hi,

I've had to hack off tiles in my bathroom, insert some new plasterboard and then I've skimmed it with Thistle Bonding Plaster to get a good level.

The surface is nice and level now and the bonding is nearly dry.

Can I tile directly onto this surface or will it need PVA or some other treament first?

Thanks

Richard C · 1 Jul 2009

chriselevate said:
I've had to hack off tiles in my bathroom, insert some new plasterboard

What plasterboard did you use & is the area behind a bath or in a shower cubicle?
Was the original wall finish conventional plaster over blocks or is it plasterboard?

chriselevate said:
and then I've skimmed it with Thistle Bonding Plaster to get a good level.

Is there a reason you used Bonding coat rather than Multifinish?

chriselevate said:
The surface is nice and level now and the bonding is nearly dry.
Can I tile directly onto this surface or will it need PVA or some other treament first?

It must be completely dry (at least a week) before you can tile it; what you need to do before you tile will depend on your answer to my first 2 questions.

chriselevate · 1 Jul 2009

Hi Richard, thanks for your quick reply,

I hacked off the tiles and original (12.5mm silver backed platerboard) in order to add a batton to take the weight of a 10mm thick shower screen above the bath.

The original wall is made of plasterboard.

I used bonding as I had some left over and I find it quite easy to put a thicker coat than several skims of multifinish.

Here is a photo of before, in the middle and as it is now.

The reason I'm doing the job is that the original fixing for the shower screen was merely to tiles and the screen was slowly falling off the wall.

This is the only shower we've got in the house so waiting a week for tiling is going to be very hard, if not impossible!?!?

Thanks

Richard C · 1 Jul 2009

chriselevate said:
The reason I'm doing the job is that the original fixing for the shower screen was merely to tiles and the screen was slowly falling off the wall.

I hacked off the tiles and original (12.5mm silver backed platerboard) in order to add a batton to take the weight of a 10mm thick shower screen above the bath.

I do remember your previous post now.

chriselevate said:
The original wall is made of plasterboard.
I used bonding as I had some left over and I find it quite easy to put a thicker coat than several skims of multifinish.

OK, now I understand what’s going on.

chriselevate said:
This is the only shower we've got in the house so waiting a week for tiling is going to be very hard, if not impossible!?!?

If you tile over it before it’s dry you will trap moisture in there & that won’t do the plaster or the plasterboard much good; at least wait until a day after it has gone completely grey or pink (the plaster can be either colour). In any case, most tile adhesive requires 24 hours before grouting & then a further 2 weeks before the shower should actually be used.

Using plasterboard in this situation is not ideal as ordinary wall board (grey) dissolves when it gets wet; Moisture Resistant (green) is better but not much, which type did you use? Since you’ve already got PB behind the rest of the tiles, it also seems a bit of a fait accompli. I would normally advise to tank plasterboard before tiling
http://www.bal-adhesives.co.uk/products/wp1-coating

but it is expensive for such a small area & there seems little point if the rest of the bath/shower area hasn’t been tanked under those mosaics, do you know if it was? You need to waterproof the surface with something to prevent water penetration which will lead to the eventual demise of the PB. You could try an SBR based sealer but it’s not really a waterproofing agent in this situation; ordinary gloss paint may work but I’ve never tried it & no idea how much additional protection it will give.
Use this;
http://www.bal-adhesives.co.uk/products/white-star
& this
http://www.bal-adhesives.co.uk/products/microflex

It will give you the best chance of keeping the water out but even these products are only waterproof in the sense they won’t dissolve when immersed in water, they will still absorb water & this is where there is a risk to the PB in the longer term.

jefoss · 1 Jul 2009

the thistle bonding is pretty good for quick drying ive used it myself and tiled over it before with no probs at all.

just make sure it is perfectly dry (a light colour)

chriselevate · 1 Jul 2009

Yeah it's drying out pretty quickly!

jefoss did you tile straight onto it or did you need to apply a primer or sealant first etc?

Right.... the guy at topps tiles yesterday sold me a bucket of BAL Grip (15kg @ £29.99) and a bag of BAL Microflex Wall Grout White (3.5kg @ £14.49).

You mentioned the Microflex but then recommended the white star product for the ahiesive.... does that matter? Should I take the BAL grip back to exchange it for the White Star?

You raised the issue of tanking.... and the answer is... it doesn't look like the previous ower used any form of tanking or prection before tiling onto the plasterboard. I have to say that the tiles were stuck very well and the only part where the water had got through was where the cracks in the tiles had appeared due to the weight of the shower screen. I was a powery black behind the bottom tile where the water had got through.

It's all nice and dry now and I've got the surface pretty level to re-tile.

Is it important to wait 24hrs before grouting and then 1week before using the shower again after grouting?

P.S. The reason I've bought big quatities of the adhievise and a tiles cutter etc is becuase I've got to install an en-suite in our mastbedroom within the next few weeks. This is where I want to tile the shower enclousure and tile the floor too. I guess I'll be using the tanking on the floor and walls onto my drylined walls before tiling.

Richard C · 1 Jul 2009

chriselevate said:
You mentioned the Microflex but then recommended the white star product for the ahiesive.... does that matter? Should I take the BAL grip back to exchange it for the White Star?

I think White Star is a superior product & always use it. Topps are notorious for high prices on BAL, you can get it far cheaper or bully them for a discount.

chriselevate said:
You raised the issue of tanking.... and the answer is... it doesn't look like the previous ower used any form of tanking or prection before tiling onto the plasterboard. I have to say that the tiles were stuck very well and the only part where the water had got through was where the cracks in the tiles had appeared due to the weight of the shower screen. I was a powery black behind the bottom tile where the water had got through.

Hopefully you’ll be lucky then.

chriselevate said:
Is it important to wait 24hrs before grouting and then 1week before using the shower again after grouting?

It’s what it says on the tin; you can grout cement powder adhesives the same day but that’s’ not what your using & your still supposed to leave it fort a week to set properly; if you use it before it’s fully cured, there is a bigger chance it will crack or water may get in there & then you will have problems.

chriselevate said:
P.S. The reason I've bought big quatities of the adhievise and a tiles cutter etc is becuase I've got to install an en-suite in our mastbedroom within the next few weeks. This is where I want to tile the shower enclousure and tile the floor too. I guess I'll be using the tanking on the floor and walls onto my drylined walls before tiling.

Makes sense then. Next time make sure you use MR plasterboard & I would use tile backer board in the shower but as long as you tank it well & seal between the shower tray & the tiles you should be OK. You don’t need to tank the floor unless it’s a wet room but what are you tiling onto?

jefoss · 1 Jul 2009

the adhesive i use ( weber wr) has a "built in" primer, so the issue has never come up, but if it was me id say no dont use pva on it.

chriselevate · 1 Jul 2009

What prices should I be expecting to pay for those products from Topps tiles? Or Where else would I be able to buy if from?

So is it worth returning my BAL grip or is it better keeping it and tiling the surface when I get chance (later on tonight)?

And do I need to do anything to the bonding plaster before tiling?

jefoss you suggest I don't but it's a different adhesive you use.

The en-suite project I'm going to be taking on is not a wet room so I guess I won't need to tank the floor. The floor is an even wooden floor board structure - will the same BAL grip and microban grout be usable for this?

I haven't boarded out the enclosure yet so I can use anything you suggest. Do you mean board it with a special type of plasterboard or use a special tile backer etc?

Thanks

jefoss · 1 Jul 2009

yes it is different, but im guessing that the bal version is the same (always check the label before using tho!)

Richard C · 1 Jul 2009

chriselevate said:
What prices should I be expecting to pay for those products from Topps tiles? Or Where else would I be able to buy if from?

Whatever you can bully them into giving you; these on line prices will give you an idea but I doubt they will match them if they know your not trade;
http://www.trades-direct.co.uk/modules/shop/noframes_ranges.asp?catid=22&rangeid=101

chriselevate said:
So is it worth returning my BAL grip or is it better keeping it and tiling the surface when I get chance (later on tonight)?

Grip is OK but White Star is better IMO.

chriselevate said:
And do I need to do anything to the bonding plaster before tiling?

Once it’s gone off, Bonding will suck like hell; a primer is recommended (but don’t use PVA) but it’s only a small area & if you just damp it down well before tilling it should be OK.

chriselevate said:
The floor is an even wooden floor board structure - will the same BAL grip and microban grout be usable for this?

I wouldn’t tile over floor boards; either overboard with 12mm WBP (but gives a high threshold) or, better still, take up the floor boards & replace with minimum 18mm WBP ply (sometimes 25mm thick is required); seal the back with SBR. Don’t use BAL Grip/Whitestar or Microban for the floor, use this:
http://www.bal-adhesives.co.uk/products/rapidset-flexible
& this for the grout:
http://www.bal-adhesives.co.uk/products/superflex-wide-joint
Sorry but that’s the way it goes if you want a job that will last.

chriselevate said:
I haven't boarded out the enclosure yet so I can use anything you suggest. Do you mean board it with a special type of plasterboard or use a special tile backer etc?

Use tile backer board (Aquapanel) inside the enclosure & Moisture Resistant PB elsewhere but if you’re plastering rather than tiling, MR board must be primed first.

gcol · 1 Jul 2009

You don't tile onto bonding - finish plaster or one coat plaster, yes, but not bonding or browning.

chriselevate · 1 Jul 2009

Hi guys,

Just got home... thanks for your replies.

Right, here's the plan of action....

1. I'll take back the BAL grip and swap it for some BAL white star.
2. I'll wet the bonding coat and apply a small key to the coat tomorrow and apply a 2mm multi finish coat over the top. Should I polish this up when it's gone off or give it a finishing coat? I'm guessing I don't want the surface too shiney?
3. I'll wait for this to turn light pink (dry all over) and then tile over the top using the white star product. Do I tile directly onto the nice pink plaster?
4. I'll grout it after finally.

How does this sound?

Cheers

gcol · 1 Jul 2009

Sounds about right. Don't polish the top coat.
Give the top coat a good few days after it appears to be dry before tiling to make sure it's suitably dry.

chriselevate · 1 Jul 2009

Right.... job done!

I've just finished applying the multifinish!

I'm desperate to get this job done as we've not got a shower at the moment while this ones out of action and with a family living here it's not easy!

So is there anything I can mix up from topps tiles or the likes that's an adhesive that'll let me grout within the same day and then get the shower up and running quicker?

I really don't think that we can last a week and half while I let the multi finish dry for 2 days, apply the star white for 2 days drying time and them wait 1 week for the grout to dry.

Thanks

diynot

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Can I tile directly onto Thistle Bonding Plaster

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