what is best proceduref laying stone on to old concrte base in church.

[jonnyc]

I have just been appointed for a very interesting fixing job in a catholic church near me.
Existing oak block flooring( which had dry rot mainly in aisles and walkways) has been removed in last few days to reveal a sub base that looks essentially to be 6 inches of concrete with no dpm. Wood block was laid over hundred years ago when church built, on a pitch adhesive which I imagine acted as dpm at the time.
Now the bitumen has all broken up and disintegrated with the the top skim layer over concrete base leaving a rough textured finish.
I dont know how builders used to get a flat smooth finish to concrete hundred years ago but it would seem it is this thin layer that has broken up with pitch leaving the surface we now have.
There is only one visible crack in concrete over whole area which is 2 linear metres between two stone columns.
I have some ideas about how i would approach this, now sub floor revealed but would be interested in anyones opinion as to how they would prepare before tiling.

Ditra mat is not discounted as an option, but the considerations are I guess, the rough texture of concrete now, the lack of dpm and therefore a natural damp problem assuming of course that there is not hydro static pressure from floor level being lower than water table, which i dont believe to be the case.
if anyone has done this before i would be interested in what process followed and in what order as i am getting very conflicting advice from different adhesive /primer manufacturers .

 

[Gazzer]

Re: what is best proceduref laying stone on to old concrte base in chu

Any height restrictions ?

 

[jonnyc]

Re: what is best proceduref laying stone on to old concrte base in chu

yes basically need to get back close to previous finished floor level, so that discounts new plastic dpm and screed . i have to deal with what i have got now level wise.
wood blocks were 25mm.
with latex/ditra/adhesive/stone will be approx 30-35 mm which will have to be acceptable and thresholds at church entry points may need to be adjusted.

 

[Time's Ran Out]

Re: what is best proceduref laying stone on to old concrte base in chu

Ardex K15.
Ditra and the rest is job done.

 

[DHTiling]

Re: what is best proceduref laying stone on to old concrte base in chu

Is there DPM in the walls..?... if you use Ditra then there is the problem of shifting damp through the dispersal channels towards the walls..

 

[jonnyc]

Re: what is best proceduref laying stone on to old concrte base in chu

No Dpm in the walls that I know of .
i agree that if I use ditra and especially if I tape joints with kerdi Coll then moisture would travel sideways as it is designed to do ,which is no good, but I dont want to discount ditra as would like the value of it as separating membrane between tile and concrete not just to prevent moisture coming up.
dave I have put together a spec in my mind and can write this down if members prefer but I have found in the past that if I give too much details of what I think, then sometimes I get very little response. I am self taught and some of beliefs are not necessarily

 

[jonnyc]

Re: what is best proceduref laying stone on to old concrte base in chu

Ardex K15.
Ditra and the rest is job done.

Does this mean I don't need a Dpm of any kind John or a primer

 

[Al@Lifetiles]

Re: what is best proceduref laying stone on to old concrte base in chu

Mapei Mapeproof ESM. Doesn't solve moisture moving to the walls though?

 

[jonnyc]

Re: what is best proceduref laying stone on to old concrte base in chu

Mapei Mapeproof ESM. Doesn't solve moisture moving to the walls though?

Thanks will look this upmtomorrow

 

[Gazzer]

Re: what is best proceduref laying stone on to old concrte base in chu

Thanks will look this upmtomorrow

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