New Extension concrete/screed floor still not dried out after 3 months

[LindaDawn]

New extension concrete/screed floor has still not dried out enough after 3 months for our Amtico supplier to put the self levelling compound down followed by the Amtico. Builder used the recommended drying accelerate. Had 5 tests to check whether dry enough to lay Amtico but failed 5th test today. Has anyone experienced this too? We now have to decide whether to keep having these tests (usually once a month) until it eventually passes (if ever) or fork out £400+ for a damp proof membrane. Sorry it’s such a boring thread.

Do you know for certain that they put a damp proof membrane down prior to the concrete floor?

Yes a damp proof membrane was put down before the concrete. The dampness tests are registering 2.1 and we need below 2, so we are very close. The first 3 tests showed improving drying of concrete but the last 2 tests were both showing the same 2.1.

Hire an industrial dehumidifier and leave it running for a few days. If it hasn't cured by now, it needs help.

Thanks we have wondered this but didn’t realise we could hire an industrial humidifier. Just can’t seem to get any advice from our carpet fitters. They don’t seem to want to advise what to do or give us any encouragement that it will dry out. They should be able to give us the benefit of their experience. Just frustrating as we are spending so much on the Amtico flooring and fitting. Thanks for your reply.

They won't want to suggest it as the humidity levels may increase when the dehumidifier is removed, and they won't want to be responsible / guarantee the flooring.

In real life, such a small difference is unlikely to make a big difference, but your choice is binary. Either dehumidify and risk installing Amtico, or find another type of flooring.

This happened to us!!! Well similar

We had a damp proof membrane put down before having Karndean fitted in our hall.
It was a black tar like substance. Completely sticky. Told it would dry in around 6 hours. Still wet 24 hours later. We had to put wooden planks down to walk on which was fun with two young kids. The floor fitters kept saying it would dry in a day or two & it never did!
The manufacturers ended up coming out to look at it. They said it hadn't been mixed properly. We ended up waiting about a month with nothing happening.
To cut a long story short we got another local fitter in. They scraped the whole thing up then put down a new dpm plus screed.

Are you certain it isn't a mistake on the fitters part? Should they have installed a dpm first? If not then go with what they recommend. It may not ever dry!

Sorry, just seen that you have a dpm! Think I'd just suck up the £400 at this point to be honest.

This is scary! So frustrating as extension been finished for 3+ months now and haven’t been able to use it. Thanks for taking the time to post. Much appreciated.

We had exactly the same thing. It took 7 months (over the winter)…..I had concerns about whether the original builders screed had been mixed properly but felt like we were between a rock and a hard place as neither the builders nor the fitters seemed to have any idea why it was taking so long nor any suggestion as to whether we could do anything to speed it along.

It did dry all by itself in the end and we now have lovely Amtico! But I remember the frustration well.

Our builder has been brilliant! He is as keen as we are to sort this out as he wants to know why it isn’t drying for any future projects. So the Amtico suppliers told our builder where and which drying acelerate to get which he did. So now the Amtico suppliers says rather than waiting for it to dry we could pay £400+ for this extra damp proof membrane. Was this an option put to yourselves?