Product for tiling on wooden floors

[Alfie25]

The last owner of my house hasn't done a great job laying the bathroom floor tiles and a couple are starting to lift/rocking and the grout all round them has cracked. I intend to try and lift these up and then refit and regrout them.


Can anyone recommend a good product for this. It appears the tiles are laid straight onto wooden floorboards, which might explain why the slight flex in the boards has caused movement in the tiles. That said, for now I just want to redo the couple of loose tiles rather than a full new floor. There seems to be products out there that are designed for tiling straight to wooden floors but the reviews are mixed. Any ideas or tips?

 

[Karis]

I assume your talking proper wooden floorboards & not crap T&G chipboard? Although most adhesive manufacturers specify products as suitable for tiling directly over floorboards in reality they are seldom very reliable, if there is ANY discernable flex in the floor, the tiles will fail again. You really need to overboard with either 12mm min WBP ply or a decent tile backer board or ideally take the floorboards up & lay a new WBP ply floor 18-25mm depending on floor joist construction. For a quick/part repair, you could try additional screws through the boards into the joists & try a ruberised adhesive such as BAL SP Fastflex . It will tolerate more movement but is expensive & will still crack if movement is beyond the flexibility limit.

BAL, Ardex, Webber, Mapei trade are all good quality trade products, avoid the cheap DIY shed stuff, it’s mostly crap.

 

[Alfie25]

I ripped up a couple of the tiles and it is overboarded with ply, unfortunately we're talking 6mm thick ply. It's a shocking job (both the ply and the adhesive application) and one which in time I'll have to redo properly, when time allows.
But for the short term, I've got a couple of new tiles to re-lay on the existing floor. Is there any reason why you recommend BAL SP Fastflex over BAL SP Flexible or BAL Rapidset Flexible?

It seems the minumum size you can get is 20kg which is way more than I need. I know there's no love on here for the pre-mixes, but I was thinking of a Toppfix ready made adhesive for wooden floors. Bad idea?

 

[Karis]

But for the short term, I've got a couple of new tiles to re-lay on the existing floor. Is there any reason why you recommend BAL SP Fastflex over BAL SP Flexible or BAL Rapidset Flexible?

Rapidset & SPF are Highly Polymer Modified S1 specification, flexible but not recommended over floorboards. SP Fastflex is an Elastomeric, S2 spec adhesive. Basically S2 spec is more flexible & the only one recommended for floorboards but, personally, I would never tile directly over them. You do have a ply overboard but it’s only 6mm & moving around so the S1 spec adhesive will fail & even the S2 might not work but worth a try if you just want to deley the inevitable.

It seems the minumum size you can get is 20kg which is way more than I need.

No it’s not http://www.tilefixdirect.com/product/BASPFF5.html A search will throw up many other outlets.

I know there's no love on here for the pre-mixes, but I was thinking of a Toppfix ready made adhesive for wooden floors. Bad idea?

I think so. A decent tub mix is fine for tiles up to 250mm on walls but no experienced pro tiler would recommend it for floors, powder only there. Just asking for trouble & will be practically useless on a floor with even the slightest flex.

 

[Alfie25]

Cheers, do you need specialist tools to mix these powders up, or given the small amount I need, can I mix it in a bucket and stir it manually? I don't have any special tools which is why I was leaning towards a pre mixed adhesive.
And it is it absolutely necessary to use a primer as stated by BAL before applying any of the adhesives mentioned above?

 

[Karis]

Cheers, do you need specialist tools to mix these powders up, or given the small amount I need, can I mix it in a bucket and stir it manually? I don't have any special tools which is why I was leaning towards a pre mixed adhesive.

You won’t need much & powder adhesive can be mixed manually or use a cheap drill mixer set slow speed. Fastflex & Rapidset have a pot life of 45 minutes Fastflex is 5 hours but I would advise you go for Fastflex as I think it’s the only one you’re going to stand any chance with. Again, I would not advise using pre-mixed addy as it will most likely end in disaster. Use Superflex grout or it will just crack again.

And it is it absolutely necessary to use a primer as stated by BAL before applying any of the adhesives mentioned above?

BAL advise priming the tile face of timber floorboards but not the tile face of WBP ply or overboard. As you have ply, strictly speaking it shouldn’t be necessary but bear in mind it’s already been tiled over once so an acrylic primer might be a good ides. DO NOT be tempted to use standard PVA.

 

[Alfie25]

Thanks again. Following your advice I bought some BAL SP Fastflex and mixed a small amount up last night just as a trial to see how it mixed and what it was like to work with, as I'm a floor tiling novice. Just laid it out, about 8mm thick on a piece of old ply.
It's had 12 hours to set now so I think it's as set as it's going to be. It isn't rock hard like normal adhesive, it's more of a 'cork' like consistency. If you poke your fingernail in it then it will indent a little. Is this correct? I expected there to be some flex in it given the 'rubberised' compound but wasn't sure if it should be that 'soft' when set.

Haven't bothered with any primer because as you say, the instructions are to prime the underside of the ply but its too late for that. I've chiselled off the old adhesive, some of which removed parts of the top layer of ply. Again, i'm hoping the Fastflex will stick to it ok.

 

[oilboffin]

Good advice there why do people put 6mmply down on boards I think it's so they think they'll get away without cutting the door down

 

[Karis]

It’s important you get 100% adhesive coverage, any unsupported areas under the tile could cause it to crack under weight. Floor adhesive is normally applied with a notched trowel (20mm round notches, 10mm deep, at 28mm centres) which on tiles up to 300mm will give an adhesive bed of 3-4mm @ 100% coverage. Larger format tiles need a slightly deeper 13mm notch but you’re going to be dictated by whatever adhesive depth you have at the moment. If the tiles have deep ridges in the back, back butter them flush with adhesive first before you stick them down.

The adhesive is elastomeric so the cork like fell is normal, if it was too hard it wouldn’t flex.

 

[tictic]

I assume your talking proper wooden floorboards & not crap T&G chipboard? Although most adhesive manufacturers specify products as suitable for tiling directly over floorboards in reality they are seldom very reliable, if there is ANY discernable flex in the floor, the tiles will fail again. You really need to overboard with either 12mm min WBP ply or a decent tile backer board or ideally take the floorboards up & lay a new WBP ply floor 18-25mm depending on floor joist construction. For a quick/part repair, you could try additional screws through the boards into the joists & try a ruberised adhesive such as BAL SP Fastflex . It will tolerate more movement but is expensive & will still crack if movement is beyond the flexibility limit.

BAL, Ardex, Webber, Mapei trade are all good quality trade products, avoid the cheap DIY shed stuff, it’s mostly crap.

You type and sound like a very regular poster that was on ere.....??....

 

[tpt]

sorry, wrong thread!

 

[tictic]

sorry, wrong thread!

So am I......


On middle east time ere....

Now Tpt....you could make a fortune out there....

Been in a place called Mirrdiff...working for a few clients....
Ya want to see my....Tan...

 

[Alfie25]

Looking at grouts, and on BALs own website it states Superflex is for Walls (and also suitable on some floors - contact the tech line) whereas for Superflex Wide Joint it says for Walls and Floors.

My joints are between 3-5mm so the Superflex would be ok as it's for up to 5mm but would I be better off going for the Superflex WJ as its for 3mm+ and clearly says ok for floors.

Also, what about microflex?

 

[tpt]

tictic - unfortunately my celtic skin would mean i'd lose a fortune on suncream

 

[Alfie25]

Just want to check, should I be using Superflex or Superflex wide joint? Most of the areas to grout are 3-5mm but there's the odd bit thats more like 2mm/2.5mm (don't ask).

I know the Wide Joint states 3mm min, but does that mean it's useless for smaller joins, or just more difficult to apply?

For some reason the WJ is cheaper than the standard Superflex, and I'm concerned about using Superflex as it states it's for Walls (though can be used on some floors)