What's the moisture tolerance for 'elasticated' glue.....

[aires69uk]

We are having some solid oak flooring glued to screed. Long story short - we have oak flooring on parquet on plastic floor tiles. Oh and we have a bit of damp - we live in a 350 year old cottage. Every year the floor has lifted and gone back down but last year it rose and didn't go back down.

We had a small kitchen extension built last year and decided that when we got the floor to the kitchen sorted, we'd sort out the problem in the lounge too.

So the floorer has decided to take up the parquet and plastic tiles and lay down some screed as a base, and glue the oak flooring to the screed.

Trouble is the floor in the lounge isn't really drying - we've got a moisture level of 2 in the kitchen, but a moisture level of 4 and 4 1/2 in the lounge. The screed has been down for 4 days now in one particular corner it's visibly not dry at the edges and like I say, when tested it comes up as 4 and 4 1/2. Now I'm pretty sure that the guy who sold us the 'elasticated' glue (£72 for 15 litres!) won't be effective beyond a moisture level of 2.

Can I get some thoughts on this please.

 

[JohnD]

what is the screed poured onto?

I have a feeling you are going to say there is no dpm to prevent damp coming up through the base.

or is there a ventilated cellar or void?

 

[aires69uk]

The screed has been laid onto concrete (I think, and if so then laid in the mid 1970's) and no DPM inbetween the floor and the screed.

The floorer's advice in fairness to him, was to strip back the whole floor and get rid of all of the parquet and plastic tiles, and to put a DPM down all over. However this is just financially impossible for us to do as we can in no way afford to do that. There would just be so must wastage of the existing oak, we cannot afford more new oak, and we cannot afford to pay for that sort of work to be done anyway.

We have no cellar etc.

The glue is Laybond L16 by the way.

 

[JohnD]

I think your floor is going to be damp, it is not going to dry out, because it is laid on damp earth with no dpm.

 

[aires69uk]

In that case would self-adhesive foam underlay be better than L16?

 

[mointainwalker]

I don't understand measuring the screed moisture content after just four days. If you use one day per mm as a guide, then it's going to be 8-9 weeks for a 60 mm screed to dry.

What is the 4 or 4 1/2 measuring system you refer to ? I thought it was usually measured in % ?

 

[aires69uk]

I don't understand measuring the screed moisture content after just four days. If you use one day per mm as a guide, then it's going to be 8-9 weeks for a 60 mm screed to dry.

What is the 4 or 4 1/2 measuring system you refer to ? I thought it was usually measured in % ?

I've no idea, he justs puts his gizmo on the floor in various different places and says, 4 1/2, 4 1/2, 4, 4, 3, 2, 2 1/2 (The 4 1/2's and 3's are the new bit in the lounge which isn't drying, and the 2 and 2 1/2 are in the kitchen which has been screed for nearly a year). I would hazzard a guess it's a thin layer of screed say perhaps no more than 6-7mm maybe - tops - if that.

 

[mointainwalker]

How thick is this screed ?

As you have been told on another thread , L16 is not flexible so you might want to return it, especially as it looks like your floor might end up too damp anyway.

I get the feeling you have walked blindly into a situation which is not going to have a successful outcome.

 

[aires69uk]

How thick is this screed ?

As you have been told on another thread , L16 is not flexible so you might want to return it, especially as it looks like your floor might end up too damp anyway.

I get the feeling you have walked blindly into a situation which is not going to have a successful outcome.

Just looked at the label and you're not joking! Now I am get getting concerned because it looks like the floorer doesn't know what the eff he's doing.

I wouldn't expect a floorer to tell me how to provide insurance, so I can't go back tot the floorer and say "excuse me mate, I know you're a floorer but I know more about flooring than you" - because that's just not true.

But what the heck do I do now?

 

[mointainwalker]

If it's only 6-7 mm then it must be self-levelling compound as you can't lay sand/cement screed that thin. I don't know how quickly that dries - need to look at the MI.

Do you have a written quote where he says what he is doing and with what materials ?

The floorer's advice in fairness to him, was to strip back the whole floor and get rid of all of the parquet and plastic tiles, and to put a DPM down all over

.

When you told him you couldn't do that , what was his response ?

 

[aires69uk]

Basically his advice was that he's given us his advice and recommendation, and he's told when he thinks we should do - as long as we are aware etc.

His decision is to glue the floor down with flexible adhesive and I know from research that this is one of the methods for solid oak flooring.

However the glue we have bought does say 'rigid' as you quite rightly point out. I've called him and he basically said "well the bloke in the wood shop said the glue is flexible and it's the right glue so it must be the right glue". That doesn't inspire me with a lot of confidence because the bloke in the wood shop isn't a floorer and I'd expect the floorer to know the EXACT glue he wanted.

I know you can either glue down solid oak with flexible glue (which this is not) or you can use self-adhesive underlay. Given the rest of the floor is a floating floor (which I know it shouldn't be but it is), which method should we go for - glue down with flexible adhesive or use a self-adhesive underlay?

How can I tell a floorer how to do his job?

 

[mointainwalker]

I don't honestly know why you were looking for a flexible glue in the first place: its main use AFAIK is for UFH which you don't have and I would have thought it would have been suitable for solid oak flooring ( in general, not with your damp )

Apart from that, I would expect a floor-layer to know what he wants and not to have to ask in a shop. It's not as if this is a completely new , unknown product, it has been around a long time.

 

[aires69uk]

Surely if you have part of a floor which is glued with rigid adhesive next to a floating floor, if there are moisture issues then the rigid floor is never going to move into an expansion gap for the very reason that it's fixed?

If the floating floor expands and moves towards the rigid part of the floor, surely it will meet resistance and either rise or cause the rigid floor to move taking the screed with it? Surely that's why he's suggested using a flexible adhesive to counteract this - except it's not a flexible adhesive?

I thought we were putting the oak on a flexible floor because the oak is going to need to move? I thought that was it in a nutshell.

 

[flooringman]

I presume the moisture meter that your flooring guy used was something like a Tramex meter and any reading over 4 would indicate too high a level of moisture for a wood floor installation.

Having said that you should not be considering installing a wood floor on a base that does not have an integral dpm. - one that sits under the concrete base of your property.

I would think when you had the extension built, if it was on a concrete base, then a dpm would have been installed underneath. This is what you need before any talk about the adhesives for your wood floor installation.

 

[aires69uk]

Yeah the extension will be okay, I haven't got any problems with that. It's the main house where the damp issue is. Only in front of the fire though, the further you go back in the room there's hardly any moisture issues at all. Laybond L19 and Sikabond T54 both seem to be flexible so I'm going to try and somehow swap the glue for one of those.