Did a job for a company we sub to 55 sq meters of amtico,floor was gypsum it was damp tested at the time and everything showed ok.WE used mapeis acrylic prime then latex plan on top it was all fitted on amticos ht as it had underfloor heating,About 4-6 weeks later a large bubble came in one corner,we ok we will return in a week to see what was wrong by this time it looked like the back wall had been hit by a bulldozer the amtico was all twisted up it had pushed the latex clean of the floor.We then damp tested it again and it was of the scale so suggested maybe a leak on the underfloor heating.The builder came back said everything was fine itsnowbeen a few months and has spread across about 10 meters this is just in 1 room the other room we took some tiles up and they were as they should have been we retuned yesterday and lifted a tile in the room with the problem and it was wet and had broke the adisive down any ideas cheers
What did you use to do a damp test. All that gypsum an anhydrate crap should be banned. Were the latence removed correctly. What were the drying times allowed. Did the contractor who put down the gypsum provide you with a drying time line and a certificate of dryness.
Its hard to test because it dries out in patches apparently. I had to stick a engineered wood down to one earlier this year and I was a bit worried about it. I left it well over a month extra than the recommended drying time. I know thats not always possible. Got to be well damp if its actually wet under the tiles?
What meter was used to take the moister reading the first time around? Was the heating run up before install? Could be a leek also. Seen one the other week that the heating installer was saying there was no leek. After some more investigation the customer said they had to keep topping up the boiler. The plumber added some additive to the boiler and they no longer have to top the water up. I would guess the plumber knew there was a leek and added a stop leek solution. Cant prove it tho.
Iv found out it was damp tested with normal touch damp tester that read it was dry they have put a hydrometer in now and it's reading 80 the gypsum has been down about 5 months
i'd check with customer how long sub-floor been down find manufacturer of said product and get their advice, most manufacturers say not to use surface dpm some recommend an epoxy.
Thats the wrong method for testing gypsum an anhydrite screeds, the only method is the hydrometer got caught on this before or rather the company I worked for did. It was a school job supa cord which was all ok as the moisture still contained can permiate through the carpet but all the vinyl areas failed, we had to strip it all out an it took 11 months for it cure correctly. During that time we found out the main contractor who installed the screed (best not name an shame them as they are one of the biggest) they know these types of screeds are problamatic an everytime they have to do one they invent a new company pour the screed get their money issue false drying documents an then close an bankrupt the company.
as above, wrong meter used. For all reading this thread. THE ONLY RECOGNISED METER TO BRITISH STANDARDS IS A Hygrometer. The pin meters on the market are actually designed for reading wood moister content (there is the odd one that does concrete) The protimeter mini for instance is a wood moister meter . It can be used as a indicator to find a sutible place to set up a hygrometer. It should not be used to take moister readings in any thing other than wood.
ive got one that you drill two holes 100mm apart, fill with cunductive paste then insert the probes. Is that type ok for testing concrete to bs? :?:
No not to BS. not a bad test to be honest tho. Its old and dated now. Was one of the first 'half' accurate test on electric meters. but like i say, not to BS so you wont have a leg to stand on if the flooring fails. PS. do you lot realise a hygrometer only costs £100 quid ! A lot cheaper than the electrical meters and the most accurate.
Done some work for a flooring contractor/cowboy, jobs up to 10km2 and they didnt know what a hygrometer was :roll:
cheapest way for hygrometers is to buy a heap of the blank humidity boxes, not the full on digi hygrometer lads. Then all you do is connect your hygrometer meter (ive the mms) to each box to check levels Each blank box is about £30 better than 100+ for the digi's Hows that for an idea?
Depends on size of area your testing. Really you only need one. But if a large area you may decide to set up more. What you need to do is get the pin meter and find the wettest area. Even if it shows as 'dry' as long as its the wettest area that is what your looking for. Set up hygrometer in this area and you should get a reading the wettest area of the floor being tested.
how does this one lookhttp://www.digital-meters.com/epage...h=/Shops/digital-meters/Products/"CEM DT-615" it's a bit cheap though using along with http://www.carpetfittersshoponline.co.uk/testo-606-2-moisture-meter-rws186-295-p.asp
even better, just buy the sleeves. But as pointed out, the mms or other good meters that read RH are not cheap. Paying out £100 quid for a hygrometer can be absorbed by most. But asking for £500 then most lads we struggle. I would advice buy the cheaper hygrometer at £100 quid. This should save you a lot of money on a failed job With the money you save then upgrade
