Newly levelled floor lifting

Thanks for the responses folks, I really appreciate the input. I've deleted a big reply that I had ready to post, addressing lots of your points individually...but but boils down to this:

Much as I might like to dig up and re-lay the floor and in an ideal world it would be my preferred option, I cannot entertain the costs and logistics at this point in the project. So taking thenode's advice I've contacted Ricky the area Ardex rep regarding a site visit.

I'll keep you posted.

Cheers,

 

What did Ricky the Ardex rep say , was it a compersite floor and did you have to take it up?

 

He wasn't able to identify the floor type but didn't seem overly concerned about it either. He advised to make sure any loose material was taken up, not to prime, then one coat of NA, then DPM 1C, then another coat of NA.

I spent all last week taking the bitumen/contaminate up (even though the NA will cover bitumen) and it's 100 times better than the example on the previous page. It does seem like an amalgamation of 40 years of different floor coverings and various DIY efforts has taken its toll...underneath all of the ****e there does appear to be a concrete base!

I did the first coat of NA today with my other half acting as mixing-monkey. We've done a pretty good job for a first attempt, in that it's gone down nicely and it's level...but we've suffered with bubbles, not immediately apparent after the compound goes down, but developing a few minutes later. These have popped and left pin-holes...which is a bit of a ****er.

Any idea what the likely cause is? I used a pin-leveller and spiked roller to lay the compound and we tried to minimise air at the mixing stage.

Cheers,

 

If you had used a primer it would have reduced or stoped the pin holes , will not make a differance with engerneer wood, so don't worry
It's like gases from the screed, rather than air bubbles in the mix

 

Pin holes are from NOT priming dude that's what I've discovered in the past

 

Surprised the rep couldn't tell you what the screed was and said go over without primer, especially when it's failed before, must be very confident in his product,
By the way did he take a hygrometer reading?

 

dont need to prime with NA

 

re the pinholing
I dont prime with NA, but do spikey it to death and always comes up nice

 

I know you DON'T need to prime but it will only help in adhesion and help regulate the drying process, you get pinholes with a very pourus concrete base, especially with quick drying screeds,
I have had many a screed company sell me a product that dosen't reguire priming but when things go wrong they said , yea but on this type you should have primed, so now all my jobs are primed no matter what,
Laid 3000 m2 of screed master 2 when it first came out, didn't prime because that's what it said , you don't need to! 4 years later I got a call saying it was a latent defect and they had an expert saying I hadn't primed and that's why it failed, luckily I still had the old mixing and tecnical details on it and proved in them days you didn't have to, a year after I laid it they changed the details to always prime,

 

This is from ardex Na details on the ardex site

On absorbent surfaces it may be necessary to damp down or prime the surface using the ARDITEX NA latex diluted 1 part to 4 parts water with a broom and allow to dry to help reduce suction and pinholes, before applying the ARDITEX NA mortar. Some solvent-based adhesive residues such as gum resin/spirit/ alcohol types may require priming as above.

I rest my case, lol

 

Not a proper hygrometer reading, he used a Protimeter (or similar).

So it looks like we had an absorbent enough sub floor that we'd have been better off priming even with NA. Ah well, we live 'n' learn.

Then I guess we should expect to see much reduced pin-holing for the 2nd coat of NA, seeing as it will be going over DPM'd NA. Nothing else I ought to be doing? I've used a pin leveller and spiked roller but didn't use a squeegee for that final polished finish...was this a mistake?

 

I guess he said the moisture readings were high, so that's why he speced DPM
Not an expect with NA but the sheet states you should have mixed a diluted version and left to dry, primer would have one the same thing, as I said it will not matter as you are putting DPM and 2nd coat, you will not get any pinholes on the 2nd coat, not sure what you mean by squeegee to get polished finish, normally use steel trowel and water just before it goes off to get polished finish if I want it, for wood there is no need.

 

1 to 8 for primer under latex thats under a dpm isnt it? enough to do its job but not enough for the moisture to mess with it.

 

Sorry, couldn't think of the correct term last night, I actually mean 'stand up leveller'. I was just mulling it over really because I've often seen them used in YouTube vids as the last stage in the process and the small areas that I hand troweled yesterday seemed less prone to the bubbles, or rather, the trowling process popped them and the compound was still fluid enough to flow back into the void. When the bubbles are left to pop on their own the compound is much less fluid, so a hole is left where the bubble was.

Anyhow, I'm waffling...despite the ramblings above I have taken on board the advice given re: the lack of priming being the culprit so I'll stick with with the pin-leveller, spiked roller and my finely-honed technique

Today is DPM day, but the final coat of NA will have to wait until tomorrow because I need another 2 bags...arse!

Thanks again folks.

 

I always use NA and I prime most of the time. Mainly because while your waiting for it to go off you can have a cuppa tea and rest them knee's!

 

Ive had this in the past, it's where the concrete is so porous, doesnt matter if you prime it still pinholes and sets twice as fast as the moisture is getting sucked out so fast.

 

Hi lads new to forum. What was the rep on saying not to prime -is he for real !! PRIME ALL THE TIME !!!,

 

Been told by the training bloke form Ardex that on Ashpalt NA will stick better not primed? I still prime it though.