problem floor - need advice

[Grace'sDad]

Right guys, I've been to price up a job and it involves a pretty large hallway - approx 10sqm but it consists of knackered asphalt running into concrete running into traditional tongue & groove. It's not level and looks bad even under underlay and carpet.

The customer wants a really good level finish on 600 x 600 marble.

What's the best way to sort out the floor?

If I bond hardibacker down using the adhesive to achieve a level, won't the different substrates cause problems potentially?
OR....

As the gaps are tight on the T&G should I just level all of it using a good latex compound and then use hardibacker?

Any ideas welcome!!!

[sWe]

Can't say for sure how I would solve it, as I don't know exactly how it looks.

Here's one suggestion.

First I'd make the whole thing level. I'd correct the worst bits by putting down backerboards with really flexible adhesive. If the T&G wasn't stiff enough, I'd correct it at this point.

You might need sanded epoxy primer on the asphalt bit by the way.

Then I'd probably put down a 2.5mm rebar netting, before leveling over with atleast 12mm latex based SLC, or whatever the manufacturer says.

This construction should be able withstand any movement.

You might want to try one of those decoupling membranes btw.

[Dave]

Easy this one...DON'T do it............

[Grace'sDad]

Dave, I'm not sure if this is your least helpful post ever or (potentially) your most helpful!

Swe - sounds like a plan. I guessed i'd have to uncouple from the floor either way.

[sWe]

Originally Posted by Grace'sDad

Dave, I'm not sure if this is your least helpful post ever or (potentially) your most helpful!

Swe - sounds like a plan. I guessed i'd have to uncouple from the floor either way.

Hehe, I agree on the helpful post part; this one might come back an bite ya in the arse if you're not really careful. Another (partial) solution might be the liberal use of movement joints going all the way down to the original substrate.

[TilingLogistics]

This will be a major mistake IMO to take on. The only way I would consider touching this job with 600 x 600 marble would be to lay a new substrate throughout. Carpet bends to shape marble doesn't No new substrate I would walk

Kev

[Branty]

IMO, no amount of prep will make this job doable. Well apart from taking up all the existing substrate, and rescreeding throughout.

[Dave]

Originally Posted by Grace'sDad

Dave, I'm not sure if this is your least helpful post ever or (potentially) your most helpful!

Swe - sounds like a plan. I guessed i'd have to uncouple from the floor either way.

It is a case of , you could not get a more unstable floor to tile too..3 different substrates and 1 in poor repair......If you can repair the asphalt floor then you could use Ditra on that and the concrete section to isolate the two substrates then sheet the boards to get an even height, plus you will still need an expansion joint where it meets the solid floor.......it can be done but more headache than its worth...........

good luck and let us know what you decide to do...............

[garythetiler]

screw down the floor boards so there is no movement put a polythene liner down mesh the floor out with expanded metal lath droplay the marble onto a sand and cement bed mixed with ronafix or sbr mix this will allow you to go as thin as 10mm with your mortar where the foor height is higher in the hall way get some marble thresholds made at you local stone yard this is not an impossible job just a very hard one other than this you will have to listen to the other guys advice and chop out the old substrate out good luck

[Sir Ramic]

I agree that the only real way to do this would be to take the lot up and refit a new sub floor. Anything less i feel will come back and bite you on the ass.