Ashphalt floor prep question!!

[DJS]

Hi Everyone, I went to look at a job on Friday, and it was yet another first for me.

Looks like I'm dealing with an ashphalt kitchen floor on top of a concrete screed.

It currently is fitted with cork tiles, and level/very strong. I managed to lift a tile and small piece of carpet in the hallway as it was the same material, and I could expose a larger area. I picked at it with a knife, and found it brittle with small grey particle's under the surface.

I have been reading up about it and understand I can tile onto this so long as I wash the floor to remove greasy residues, and then use a primer and 1pt flexible adhesive. Using porcelain tiles BTW.

So I'm wondering have I identified the floor correctly? From what I have read and written, is this the way you would go about tiling it or can you add any suggestions?

Many Thanks
Denis

 

[White Room]

Have you tapped it to see if it is hollow or solid

 

[DJS]

Yes, definately solid. Tapped it with hand and foot. Why you ask?

 

[White Room]

If it was giving a hollow sound then it's not conected to the concrete

 

[DJS]

I might have seen similar before, where there was a screed but parts of it were just SLC over some wooden boxing in where the water supplies and manifold for the CH was located. Pipework is behind drylined walls in this case. Is that what your checking for?

I also noticed there is only only 13mm spare above the washing machine and tumble dryer, so it's possible this job maybe a no go for now anyway. At least until the couple decide to replace or raise the base units and worktops, or buy new white goods!!

 

[DJS]

I was wondering about the need to lay a decoupling membrane, or cement boards, but this would definately push me over the height limit I have available!!

Just wondering if I have got the sub-floor type identified correctly??

Cheers

 

[DJS]

If it was giving a hollow sound then it's not conected to the concrete

Can you help me any further whitebeam? Do you mean like an unbonded screed or bonded screed?

I said I would be back intouch with the customer by now. So I need to ask them for more time to investigate thoroughly!

Cheers
Denis

 

[White Room]

How thick is it, is it just like a glue that fixed the cork tiles

 

[DJS]

I picked away at a bit with my knife and the hole I made was approx 10mm deep. Thats when I noticed the grey bits embedded in the black stuff.

I was worried about making the hole too big, as I had the customers stood over me, so I didn't dare to dig any deeper!

The cork tiles were definately stuck to the black stuff with an adhesive. Is that enough information to go with?

If I need to go back and check anything, I will.

Many Thanks
Denis

 

[White Room]

If it's stuck solid then...

I would de-couple but would slurry with sbr and cement first and use a spf adhesive to fix the membrane down with.

 

[DJS]

Thanks Whitebeam. It's good and bad news for this job then.

I always suspected overboarding with 6mm cement boards or a DC membrane maybe required.

So the good news is it can be done.

The bad news is, if any extra prep work was required to this floor, it will bring the floor level up too much. The white goods (washing machine & tumble dryer) won't fit back under the worktops once I've done the prep, and fixed the tiles.

So unless anyone knows any tricks to make a washing machine smaller, then I will advise the customer to put the job on hold for now!! (I've already checked if the feet can be adjusted and they are already at the lowest point).

The customer has recently purchased the house, so they did mention a possible kitchen re-fit in the future. So I guess I will have to wait until that work is done, before they will have room to fit the tiles and white goods under the worktops!!

Thanks again for the advice

 

[DJS]

Only me again!! Just wanted to start the final chapter on this....

I've been doing some more research about the slurry coat today, which lead me to call several companies, and their advice has changed my mind from what was suggested!! If you can tell me why the slurry coat would still be recommended/benficial after reading this infomation then please feel free to respond, and I would consider it. But I don't see any reason not to follow manufacturers guidelines.

Firstly, I called my old training centre to confirm 100% that what I was looking at was ashphalt. Relieved to hear I got that bit right. There advice was also the same as given earlier in this thread. Ie. Slurry coat, DC membrane bonded with SPF and tile with SPF.

Second, I started to wonder about cleaning the old cork tile adhesive off, and based on the tech department advice from LTP, I have been advised best to use LTP Solvex.

Thirdly, I called my local shop and because they were not 100% asked me to check with Mapei tech dept. I normally use PrimerG and wondered if it was suitable to mix up with a slurry coat, or if not, did they sell any kind of SBR Primer to mix up with the slurry coat.

The mapei tech dept guy went away to check with one of his colleagues and called me back about 20 mins later. Said this kind of question was a first about the slurry coat mix, and he advised use of keraquick & latex additive (no primer) to bond the DITRAMAT straight onto the cleaned ashphalt surface. Also, keraquick + latex to apply the porcelain tiles to the DITRA. So for now, that is what I'm going to go with, although it does seem to push the materials costs up.

Just wanted to say thanks again to Whitebeam for your advice. Everyday is a learning day as they say!! I feel happy I can give a guarantee with the work now.

Cheers
Denis

 

[White Room]

Thanks for the update Denis.

 

[Time's Ran Out]

So unless anyone knows any tricks to make a washing machine smaller, then I will advise the customer to put the job on hold for now!! (I've already checked if the feet can be adjusted and they are already at the lowest point).

The 'worktop' part of these appliance usually gives you 30mm to play with if removed and replaced with a thin alliminium sheet to protect from dust etc.

 

[DJS]

Thanks for that tip TJ. I've replaced a belt on a washing machine before, so I guess I already know how to do it!! I've just never recommended it as part of a job before, because I wouldn't be happy about leaving it with no cover. But that suggestion seem's to solve the problem, if the customer is happy to go ahead with it.

I tried to call the customer today, but got through to his voicemail and asked him to call me back. So I've not spoken with him yet, and can still offer to do that.