Floor tiles over bitumen?

[silverhornet]

I'm in the first steps towards installing a new kitchen and I have a little problem.....

The existing floor surface is parquet over concrete - however, due to the removal of a walk in pantry and a change in layout over the 50's original kitchen I have two different levels of concrete (one 30mm lower than the other) so I was going to simply lay concrete into the lower sections and level.

The problem is, what do I do about the bitumen that was used to stick the parquet down which is covering the majority of the kitchen? Can I simply concrete/level over and then tile on top? I have seen lots of threads but no definitive solutions.

The kitchen is in a first floor maisonette which I am trying to bring up to date, so this could well be the beginning of many cries for help.....

 

[Softus]

The problem is, what do I do about the bitumen that was used to stick the parquet down which is covering the majority of the kitchen?

Sweep it clean, rough it up with a wire brush, prime it with a proprietary primer.

Can I simply concrete/level over and then tile on top?

Hm, yeahr, but no, but yeahr, but 30mm is rather a thin layer of concrete.

You'd be better off using a latex-based screed and bulking it out with chips.

 

[joe-90]

Oven fries are best.

 

[Moz]

The problem is, what do I do about the bitumen that was used to stick the parquet down which is covering the majority of the kitchen?

It depends what your mud mix /adhesive manufacteur says , if they say you can lay on top.....
no worries go ahead !!

but generally they always say that a bitumen substrate is a Big NO/ NO .......an you need to get it off or screed over !!!

 

[Softus]

but generally they always say that a bitumen substrate is a Big NO/ NO .......an you need to get it off or screed over !!!

Moz, there are primers designed specifically for non-porous surfaces such as bitumen.

 

[Moz]

like BAL PRIME APD.....maybe

personally I like a good substrate to tile on ....lol

 

[Softus]

like BAL PRIME APD.....maybe

Indeed so. Or Weber iboprim, to name another.

personally I like a good substrate to tile on ....lol

How do manage to make that sound smutty?

 

[silverhornet]

Many thanks for the info.

So, having read many threads and coupled with the good advice here I'm going to:

1) Fill the 2 holes (1 = 90cm x 2m, 2 = 60cm x 1.5m) with 4:1 sharp sand/cement screed as the depth is actually =>50mm after applying PVA.

2) Remove the remaining parquet tiles, scrape any large bitumen chunks off, roughen with wire brush, vacuum and..........?????

Now, this will probably still leave me with slightly different levels. Best practice will no doubt state that I should use self leveling screed over the entire floor to ensure that it is indeed level (the two holes are at either end of the kitchen).

So, I take it I'll need to prime the bitumen remains with a primer for non-porus surfaces, wait for the new sand/cement to dry and then apply the S L compound as per manufacturers instructions.

Questions:

Is this the best course of/correct action?

How long should I leave the PVA to set?

How long should I leave the sand/cement to dry/cure?

Any primer recommendations

As I'm laying tiles, do I need to use s l screed over the whole area or only over the newly filled holes - last thing I want is the floor to start cracking so need some guidance over drying times and best course of action.

By the way, time is against me here as the kitchen units are being delivered tomorrow, sparky coming on the 19th and a desire to have the kitchen complete by Christmas - bugger!

 

[Moz]

*I should use self leveling screed over the entire floor *

I would do this ...then bitumen is covered ...an floor is one base /substrate
use Bal Multibase for levelling or many other good levelling products ,
ask at your local tiler shop NOT the Diy Sheds .....

levelling curing times differ but usual 2-4 hours

then use Bal Fastflex for the mud/adhesive

then use bal grout ...

 

[silverhornet]

Top tips, thanks Moz (and Softus).

Will keep you posted on the outcome