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

Save you some time

products

 

[jonnyc]

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

My current thoughts are:
ball p131 primer.
ball green bag withh 114 additive to smooth out rough concrete base.Only thinking of this latex as compatible with base that has moisture in it, because of no Dpm.
ball stop 75 liquid Dpm followed by ditra mat fixed with flexible adhesive.
fix stone on top of ditra with setaflex.
what do you think ?

Any thoughts welcome

 

[jonnyc]

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

Save you some time

products

Thanks . This sounds like the ball stop 75 so we are thinking along same lines.
Liquid resin Dpm seems logical

 

[peteablard]

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

Jonny, you've just given a very similar spec to what I've used a few times when laying vinyl floors. P131 (Which I still use more than any other primer) We used a different latex and then Laybond DPM. As we were laying vinyl the DPM was latexed over again but had to be primed first. All I would say is check if the DPM you use can accept the tile adhesive directly or if it should be primed first. Can't remember if neat 131 was used to prime it or if something else was supplied.

 

[jonnyc]

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

Jonny, you've just given a very similar spec to what I've used a few times when laying vinyl floors. P131 (Which I still use more than any other primer) We used a different latex and then Laybond DPM. As we were laying vinyl the DPM was latexed over again but had to be primed first. All I would say is check if the DPM you use can accept the tile adhesive directly or if it should be primed first. Can't remember if neat 131 was used to prime it or if something else was supplied.

I am not set on using ball products. They are just the only one looked at so far.
i will definitely use tilemaster adhesive but don't think they have a liquid Dpm or latex suitable for overlaying a subfloor with no Dpm.
i would rather use same manufacturer throughout.
is lay bond best price for this type of latex required .

 

[rainsco]

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

hi jonny, i have done a church in germany years ago and this was a special thing. we had to use grave for the ground, then a lean concrete and absolutly no waterproofing because otherwise you got the water in the walls. but this was in the ground floor without wood and so on.

 

[peteablard]

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

I am not set on using ball products. They are just the only one looked at so far.
i will definitely use tilemaster adhesive but don't think they have a liquid Dpm or latex suitable for overlaying a subfloor with no Dpm.
i would rather use same manufacturer throughout.
is lay bond best price for this type of latex required .

I'm not sure about pricing Jonny, I was doing this as a subby and all materials were supplied.

 

[jonnyc]

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

Ive had a look at levels and they are pretty shocking. There is 40mm variance in the base and i am restricted by a number of doors where stone must come flush.
will have to not lay level and just work to each door.
i cant go over 10mm bed as tiling on top of ditra as that is the max they allow so will have to make up some of the dips and low points which are not near the doors in extra levelling compound with granite chips .
what i am looking for is a latex that can go on subbase which has little damp but can have granite chips added which is not too expensive.
Best price i can get on ardex na and bottle is £21.40 and green bag and 114 £ 16.50.
Anyone know of a cheaper latex than this that does same job and where to buy cheap granite chippings.