Engineered flooring bouncy disaster

Hello there,
I would like to seek some opinions on underlay for a floating wood floor installation. I will tell the whole story of horrors....

We had some engineered flooring installed by some dodgy builders and it was a very poor job. It visisbly bounced all over the place and was extrodinarily bad, it was literally like watching waves when someone walked on it.

I should explain that our house was previously extended. It has a solid concrete floor put down at seperate times and as a result is quite uneven. The original house was contructed early 70s with extension to the living room late 80s. As a result our living room is made up of 3 seperate concerete pad areas that are all joined together.

When the origonal floor was put down no effort was made to level the floor and to compund the issue a proper expansion gap was not left either. It was such a bad job we didn't want them to even try and put it right so got some others in to assess the problem.

We have a few other builders and flooring companies to have a look and assess what the problem was. Everybody said it wasn't levelled properly and some people said the concrete floor should be dug up and rescreeded whereas others said that provided the floor was levelled properly it would be ok.

We had the floor completely redone (including buying new engineered wood flooring) and spending probably £1.5k on levelling compounf (over 40m2). The job was signifiantly better but ultimatly I'm still dissapointed with it. There is visible movement in a number of areas when walked over and there are plenty of areas that creak and squeak when walked over.

The installation is now composed of solid conceret floor which has been screeded with a latex lavelling compund (Screedmaster if I remember right). Then there is a 3mm foam underlay with DPM followed by 5mm Wickes fibreboards and Boen engineered boards on top.

It's really quite dissapointing to have spent so much money (twice!) and still not to be happy with the results and I wonder if there's anything that I can do to improve the situation. Especially as I've had a Khards engineered floor in a previous house that was as solid as a rock.

1) Should I consdier puling up the boards and glueing down to the concrete floor for stability and to stop any bouncing?
2) Should I consder putting a better underlay underneath - maybe a rubber mat type or maybe the adhesive types?
3) Should I have actually got the conrete floor dug up and rescreeded to get a stable floor? The second contractors said that they could keep going and adding more latex but there was a limit before the latex got so thick that there was a risk of cracking and as such wouldn't recommend any more levelling be applied.

Basically any advice out there generally as to anything practical I can do to improve the situation?

Many thanks for any advice
V

You shouldn't have added the 5mm fibreboard underlayment - this can increase a bouncy feel to the floor.

How thick and wide are the engineered boards?

HI there, thanks for the reply

It's Boen engineered Oak that is 13mm thick and 138mm wide. Must admit I did wonder what the point of the fibreboards is. I think the contractor was quite worried about how unlevel the floor was underestimated the amount of levelling compund required and hoped fibreboards would take some of this out.

Do you think I would be better off replacing the bog standard 3mm foam underlay with some of the rubber matting type or even something else superior?

Many thanks for your advice
V

We would use Timbermate Excell (3.6mm rubbery underlayment including a DPM)

WoodYouLike said:

We would use Timbermate Excell (3.6mm rubbery underlayment including a DPM)

Click to expand...

x2 so would we.

It sounds like although the correct methods have been applied with regards levelling the floor, the floor may still not have been checked with a straight edge to ascertain how level it was. I would suggest that if it were possible, extra screed may be required in those areas that are still uneven.

Or the bounce is caused by "hills" - where too much screed has been added in one area, creating a localised "see-saw" effect

Thanks very much for the replies.

Is it correct that there is alimited thickness of screed that can be applied before I run the risk of it cracking?

The screen used was Laybond Screedmaster 2 Ultimate which is a latex based levelling compund I believe. The chap who put it down was telling me he'd applied a lot and in some areas of the floor it was getting on for 10mm thick (applied in a 2-3 seperate coatings) and that it would be very risky to apply any more (it wasn't bulked up with aggregate).

I'm trying to decide whether to take out the fibreboards and apply a final screed of 3mm but am quite nervous about the latex compund being too thick.

Thanks so much for the advice chaps
V

Some of them can go a lot thicker, is there a helpline phone number on the bag? or they may help you www.laybond.net

I have seen the lads hired the diamond floor grinder on building site for the fine grinding of screed but don't know much about it. Don't want you waste any more money though

I don't really see the point of applying levelling screed if it isn't going to be done properly and fully level the floor. Maybe battens with packers, planed to fit to provide a level surface would have been more economical (probably no help to you now).