1965 is when a dpm became mandatory. However if the dpm was just thrown on to hardcore without a coating of sand it can easily get perforated and fail. Do you know if the smoothing compound was a water mix or a latex mix ? And dare I say it .... was it a builder that put it down !!
Marvellous...poor products over poor prep So the compound has to come up, leaving me with what was there before; a combination of a sound concrete screed with some vinyl tiles and possibly some sort of Marley bitumen product. Do the old tiles and bitumen have to come up, or can they be left if they're sound, assuming correct priming to follow?
The product was Cementone Cempolay, but I don't know if that's a water or latex mix. Not a builder! A background in French polishing (stop sniggering at the back!) now specialising in parquet flooring. So he says.
Who, me? *goes back to double check pics* No, really, about 8mm. Maybe 10mm max, but nothing obscene.
Without a damp reading difficult to advise correctly, definately bond it to the subfloor that's the right way to fit t&g really. You will probably need to uplift everything right down to concrete, get a surface dpm done prime everywhere then use a high compression strength screed. If no working DPM then you may need to dig up your concrete and replace it with new and new mechanical dpm, then follow above after minimum of 4 weeks. Another option would be to get it asphalted and float the flooring over the top this isn't the best way asphalt only lasts 20 years or so generally and in my experience wood should always be fixed direct to subfloor especially t&g (you can't bond to asphalt the compression strength is too low).
I would've thought that after getting the old latex up, provided the old tiles are soundly fixed, then you could go over those and the bitumen with a primer such as F.Ball 131 and definitely Arditex NA latex - not the cheapest but your best bet when going over older floors with different compositions. If you're floating the wood floor then make sure you lay a visqueen type plastic dpm sheet first.
Just googled the screed. Looks like water mix to me and made by bostik. Did it come in a white bag Richard ?
Thanks, I really need to explore avenues that don't involve digging up the concrete...tell me more about prime/DPM/screed options. I've seen >this old post< from Matt on DIYnot which surprised me, in that I'd have assumed a DPM goes down first, but clearly not in this case. Is it dependent on the products/system used?
Freely, I like you, you're talking my language! I know of the F.Ball products, but if I'm using their 131 wouldn't I be better off sticking to their system and using one of their products on top?
I think your first course of action would to get an rh reading of your floor. Then go from there. You could , as a diy method , place a m2 of polythene down on the floor , taped at the edges , and see if you get any traces of moisture underneath it.
It is made by bostik and laybond. I know a rep well so will drop him a text. I've used some of there others screeds from Travis Perkins and I thought they were good to be honest.
f balls version of na is only just being released, 1200 pro, not sure what the compression strength is though.
