Laying karndean over parquet

[garyo]

Hi chaps,

I have a room that has the following construction :

100mm concrete slab
Dpm
40mm screed
20mm parquet herringbone - nice and flat/solid.
15mm carpet and underlay

Due to the levels in the rest of the house what I'd like to do is remove the carpet and underlay, screw down 6mm ply, then glue 3mm karndean or equivalent.

I've done some reading and im not clear whether this is advisable due to the parquet sweating and blowing off. It's there a particular combination of products that would save me having to pull up the parquet and backfilling with 25mm ply?

Thanks

Gary

 

[dazlight]

What year was the parquet laid?
How do you know it has a DPM under it ?

 

[garyo]

What year was the parquet laid?
How do you know it has a DPM under it ?

The house is 1965. I've chiseled it up to see what's going on. My sds has shown the dpm who's boss :

 

[dazlight]

Good to know that. I treat all floors before 1970 with no Dpm and put a liquid one down. Just goes to show some houses did have some. 1965 was the year builders were meant to put one in.

I'd still be doing the same if it was. Job of mine due to the old Visqueen sheet could have holes in it.

 

[garyo]

I can only guess that the floor is the same age as the house, but I suppose the odds are good. It may well only be 20 years old though.

What do you think about the general concept of putting antico/karndean over parquet?

 

[dazlight]

A way I'd do the floor is
Grind off loose adhesive
2 coat liquid dpm like Ardex DPM1c, fball stopgapF77, Uzin PE404
Prime and Screeding compound at 3mm

 

[chappers]

doesn't seem like you've got any damp issues and you already have DPM and bitumen adhesive I wouldn't worry.
The general theory of glueing Karndean to the parquet is sound, seams a real shame that you have floor height issues as that parquet would probably sand up lovely. Could you not live with a 10mm ramp threshold at the junction.

 

[garyo]

The general theory of glueing Karndean to the parquet is sound, seams a real shame that you have floor height issues as that parquet would probably sand up lovely. Could you not live with a 10mm ramp threshold at the junction.

I'm adding a 3M by 4M open-plan extension to the room, so keeping the existing parquet would need me to fit equivalent/matching parquet in the new part. The two other parts of the house have already had some kind of Kardean-like floor bonded to the top of the historical parquet, meaning they're already slightly higher, so by doing the same in this room I'm be doing myself a favour. I agree though - it's a shame.

Thanks for the reassurance that the general theory is sound. Would you bond it direct to the wood, and only use 6mm ply if the blocks were loose/uneven? Would you care to recommend an adhesive?

Thanks

 

[chappers]

depends how flat it is, if perfect then yes, but you say you have a height issue, so you will need to put something over the top, exactly how much do you need to make up over the parquet.
Probably best as Dazlight suggested to use a fibre reinforced screeding compound, you can't apply Karndean direct to ply, the joints will most likely eventually show through.
Karndean do their own adhesive