Polybond concrete floor before solid oak glueing?

smokingman

Hi all,

We're laying solid oak floors in about 5/6 weeks (moisture reader gave 22% yesterday ) and we're probably going to glue them. The guy that we had doing the moisture test told me that the best thing to do would be to polybond (4 parts water to one part polybond) the concrete floors now and let the whole lot dry together before laying down the foam and glueing the boards together on top.

Can anyone tell me if this is a valid way to lay solid oak floors of 120mm width?

Cheers in advance!

smokingman

I got something called PVA bonding stuff and am wondering, if I use this to "seal" the concrete floors, will I just be sealing the moisture into them and is this a good thing considering my moisture content test was at 22%?

Cheers for any advice in advance.

hopalong_ie

Hi,

Why are you using foam, how is the underlay/foam bonded to the conrete, the idea of the glue is that you glue directly to the concrete floor, the other option is an underlay available in B&Q which negates the need for glue but i havnt used it, but glueing to standard underlay i think is a huge no no. I found this a useful read.

http://www.hardwoodinstaller.com/hardwoodinstaller/gluedown-prep.htm

CJhaughey

What the PVA does is seal the floor, this stops dust, but will also slow drying of your slab.
Have you got UFH? If you can run that to dry the slab it will help a lot.
I would lay some polythene sheeting first, then the foam then the wood.
this will stop the wood from moving too much.

smokingman

hopalong_ie wrote: »

Hi,

Why are you using foam, how is the underlay/foam bonded to the conrete, the idea of the glue is that you glue directly to the concrete floor, the other option is an underlay available in B&Q which negates the need for glue but i havnt used it, but glueing to standard underlay i think is a huge no no. I found this a useful read.

http://www.hardwoodinstaller.com/hardwoodinstaller/gluedown-prep.htm

We're using foam under the wood as we are glueing the floorboards together but not to the floor itself. It'll effectively be floating on the foam.

We haven't got UFH but we're just anxious to get the floors down as this is the only thing stopping us from moving in (easier to put the floors down if we haven't any clutter in there). Should we not seal the floors so if we want to get the floors dried properly?

Minder

Concrete dries through a chemical reaction rather than evaporation. If the concrete floors were newly laid and immediately tested with a moisture reader, I would expect a high reading. If retested after several weeks and the readings are still high, there could be a problem with moisture coming up through the slab.

The curing process continues for weeks, with the concrete getting harder as time goes by. If you lay wooden floors early on the concrete, you could get moisture damage in the boards. The drier material (wooden boards) could attract moisture from the concrete floors, causing the wood to warp.

There are proprietary products available to seal concrete and act as a moisture barrier (rather than waiting for the full curing period) - those may be better than PVA. Or get a retest done.

gsxr1

if you are getting 22 on the moister meter then hold off with the expensize floor. Each one of your boards will cup... That is a very high reading. How long ago was the pour.?

you should ideally be looking for 3%. Keep your heating on this will help.

Poly bond is not really designed to seal concrete but is great for keeping the dust down.


1000 gauge polythene under the foam is the way forward if you intend to float the floor. Make sure all the joints are well taped.

Personally I would recommend glueing the floor to the concrete. It is a much better job for solid. It feels better under foot.

osnoyl

gsxri is right in what he is sayin . i fit floors for a living and would never do it till its 3 or 4 %. what kind of a moister tester was used usualy they just read up to 6 % it might be a tester for timber .

De_man

gsxr1 wrote: »

Personally I would recommend glueing the floor to the concrete. It is a much better job for solid. It feels better under foot.

agree with gsxr1 moisture level on my floors was 3%, glued solid oak directly to floors with "Fast 98" (chimvers) - no probs - no cupping

the glue was expensive though

smokingman

The floors were poured September 17, 2007 and the house made waterproof January 21, 2008. The heating has been on for about 6 weeks now with the windows being open for some fresh air at the weekends when it's dry. The guy testing the floors a week or two ago nailed two nails into the concrete and had some sort of potentiometer reading between the two.

We're going to hold off PVAing them until the moisture comes down and we'll seal it then - until that happens, we'll amuse ourselves with sanding and polishing the doors/skirts and architraves

Cheers for the advice lads, much appreciated.

gsxr1

smokingman wrote: »

The floors were poured September 17, 2007 and the house made waterproof January 21, 2008. The heating has been on for about 6 weeks now with the windows being open for some fresh air at the weekends when it's dry. The guy testing the floors a week or two ago nailed two nails into the concrete and had some sort of potentiometer reading between the two.

We're going to hold off PVAing them until the moisture comes down and we'll seal it then - until that happens, we'll amuse ourselves with sanding and polishing the doors/skirts and architraves

Cheers for the advice lads, much appreciated.

something may be wrong if you are still getting such a high reading. I would suggest getting an engineer to have a look. Your floor should be very close to ready by now. Not trying to worry you . the meter may be way of calibration or misread by the operator.

smokingman

gsxr1 wrote: »

something may be wrong if you are still getting such a high reading. I would suggest getting an engineer to have a look. Your floor should be very close to ready by now. Not trying to worry you . the meter may be way of calibration or misread by the operator.

It was a friend of a friend that did the reading - anyone know how much a reader costs and where I could get my hands on one if they're not too mad dear?

osnoyl

i paid €1400 for mine but you can hire them from most hire shops

smokingman

osnoyl wrote: »

i paid €1400 for mine but you can hire them from most hire shops

Bejeepers, never even thought of that!
Nice one osnoyl, cheers

gsxr1

smokingman wrote: »

It was a friend of a friend that did the reading - anyone know how much a reader costs and where I could get my hands on one if they're not too mad dear?

haven hire have one in naas. I think.?? our foreman hired one latly and that where we keep out account. its a really good one.

hopalong_ie

Hi,

Just to ask but what thickness is your solid oak floor, i've been informed that you must glue to directly to the subfllor if its 18mm or over, 15mm can be floated but 18mm cannot,

smokingman

Far as I know mine is 18mm.....might have to check that but pretty sure that's it - so is that right? I have to glue them as opposed to floating yeah?

osnoyl

for 18 mm you can use Elastilon underlay ,it is pretty expensive @ €10 per sqy but it has a sticky side that your floor sticks to and there is no need to glue joints and if your floor moves or lifts just trim a bit from around the wall and your floor sits back down to where it was .glue direct to concrete is good too but then you have to have your moisture perfect 3 to 4 % and then floating by gluing the joints is ok ,i have done it lots of times and perfect but try not walk on floor untill next day because if the glue brakes in the joints it can cause the floor to come apart

smokingman

Hi again all,

We'll be starting the floors this weekend and I need to find out what wood glue to get. I'll be floating the floors after all (polybonding floor and putting foam underlay down) and will just need something to glue the tongued and grooved boards together (not to cement floor but to each other).

I went to B&Q yesterday evening and and was told that the best thing to get was something in a silicon-tube-like yoke - said to yer man "I've 141 square meters to do, that tenner a tube thing isn't going to do me 10 meters each, do you have anything I can get in bulk without needing a new mortgage?!" ....

This was followed by "er...um....that's the best thing for the job right there so it is alright" <skuttles away>...

Anybody have any glue recommendations?

gsxr1

smokingman wrote: »

Hi again all,

We'll be starting the floors this weekend and I need to find out what wood glue to get. I'll be floating the floors after all (polybonding floor and putting foam underlay down) and will just need something to glue the tongued and grooved boards together (not to cement floor but to each other).

I went to B&Q yesterday evening and and was told that the best thing to get was something in a silicon-tube-like yoke - said to yer man "I've 141 square meters to do, that tenner a tube thing isn't going to do me 10 meters each, do you have anything I can get in bulk without needing a new mortgage?!" ....

This was followed by "er...um....that's the best thing for the job right there so it is alright" <skuttles away>...

Anybody have any glue recommendations?

normal PVA wood glue.

waterproof stuff if a wanna be fancy