You could use the Ardex P51 primer but i've always prefered the f.ball 131, i find it "stickier"! In my experience provided the primer is suitable for the use then manufacturers will still back it. They would obviously prefer you to use theirs though. A laybond rep once told me to use the 131 with their screedmaster 2 ultimate latex rather than their own primer because it was cheaper! I think Arditex NA is the best latex you can get for problem subfloors so i'd definitely use it over any f.ball latex.
Thanks for the help chaps. Had a couple of guys around last night to view & quote, both commented on the apparent total lack prep and the fact that primer hadn't been used. One of them noticed DA (or was it PA?) adhesive from old vinyl tiles that hadn't been taken up and the Cempolay had just gone on top of that. The floor does have a high moisture reading so will proceed assuming no damp course. I've booked one of the guys (local, flooring by trade, does lots of Kardean / Amtico etc.)...he'll be pulling up the Cempolay and making good the sub-floor, removing the old tiles & adhesive and so on, then using Uzin L3 Gold Moisture with 2 undiluted coats the system primer. I've done a search for this product on the forum and it seems well regarded. Once bitten, twice shy, I'll be on-site this time to keep an eye on things. The key thing for me is to make sure that he goes right back to the original screed and that it's in a sound condition to receive the primer. Any tips or advice, anything to watch out for...probing questions to ask? Cheers, Rich
what's the rh reading if over 93% or no working dpm L3 isn't suitable mate, only Ardex DPM 1C is recommended by the manufacturers when DPM is missing.
The reading in 1 area is about 800 which I'm told is under 90% rh? The rest of the floor is lower than this. Due to local supply issues with the Uzin L3 Gold Moisture additive, my floorer came back with Screedmaster Rapid DPM (up to 95% rh with 2 coats) and Tremco SX302 underlayment. Today was spent taking up the old floor and it now looks like this ready for the above products tomorrow.
Richard I am new on the forum but the picture looks as if its got old plaster all over it, before I laid any Dpm/ latex on this i would either scarify, scabble or shot blast to remove any loose surface contaminates, or wire brush on a scrubber if they don't have any of the above machines. Any DPM is only as good as the base it's laid on, if it can be scraped up easily then it needs to come off,
All day today was spent with electric chisels and a scraper, taking up anything that would come up. What's left is well adhered to the screed underneath.
You should really have a rh% reading. I wouldn't fancy putting a Dpm direct to that subfloor but then again I've not used that product
i have not read the full thread. I have simply skipped to this page. First off you have a reading of 800~? 800 what ? the reading of 800 you have i will guess was done on a yellow meter in scan mode? well this reading means absolutely nothing. It is not any sort of recognized scale. it is no different to you making up your own language and expecting someone to understand it. The only BS standard is a RH reading. There is NO conversion chart for made up scales (the 800 one you have). Basically because it is very un-accurate so there would be no base to work from. There is a reason why it is not a BS standard! Looking at that sub-floor you can not apply a dpm to it. It needs preparing correctly. That being with a shot blaster/scrabler etc. These will remove the black contamination you have. Think of it like this. If you buy a new car with rust and you paint over the rust it will soon show its face and the new paint will fail. You need to remove the rust first. Same goes for your sub-floor.
Thanks Matt. I've see scabblers for hire but they vary quite a bit - are either of these suitable? If not, could you post a link to one that you'd recommend and is readily available to hire. It's a 50m2 domestic job and the contamination that needs to come up looks like a combination of old tiles and bitumen. As stated previously, what's left seems to be well adhered...it's probably about 1-3mm thick. http://www.brandontoolhire.co.uk/en/decorating-tool-hire/143-rotary-scabbler.html http://www.hss.com/g/30618/Multi-Head-Scabbler-Air.html Cheers,
After looking at your previous pictures I think you could have a major problem and could explain your problems, To me it looks like a composition screed, rather than a standard sand and cement one, that's why it looks beige and like plaster, it has score marks from the chisels as if its soft, If it is an old composition screed it needs all digging up, sorry but that's what I think. Can you give any history? It looks like it is a beige composition with a thin layer of cement/latex with blackjack adhesive on top, If you had vinyl tiles the blackjack might have held any moisture back. The thin set of blackjack and thin latex is showing the soft beige screed underneath. If it is what I think it is DPM will not work, If you can't take it up, you could possibly level with latex and isolate with breathable membrane, like Altro evelay , Fballs isolater and possible float floor on top, with viscreen in between, basically if its composition it needs to breathe and have an airflow but the wood can't be in contact with it, could be done at your risk but that would be the cheaper option, Any body else think it could be composition ? You will soon find out if you use the scrabbler, it will just turn to dust as its soft
i think its a magnesite composition floor screed, try taking a piece of the beige product and try burning it over a lighter, if it glows at the edges then I am correct, it is also electrically conductive so that is why it looks dry but you are getting the 800 reading with your damp tester, That's my thoughts from the pictures, not sure that many would know what a magnesite screed is. Most have been dug up or still covered with carpet. Good luck and I hope I am not right for your sake. Gary
Why don't you get a rep from ardex / fball out? They will test it, spec it and guarantee the job for you. Ardex tech tel:01440 714939 FBall tech tel: 01538 361 633
