Damp under wood floor

[Hban]

I have just taken up a solid wood floor ready for installation of a wood floor throughout the ground floor of my house. Underneath is 20mm ply, then 20mm chipboard and then blacktop over a concrete base.

The wood floor company spotted that we have damp showing between the chipboard and the ply although it does not look like the damp is getting through the blacktop.

I am struggling to get anyone to come and look at it and the best advice I have had over the phone is that the chipboard can sweat and that we probably had moisture trapped between the black top and the varnish on the wood floor.

Can anyone advices on whether this is feasible and what I have to do to get round the situation?

I am desperate for help as I have two small children and now ground floor to my house, therefore no kitchen!

 

[tim00]

This is a Flooring Question really.

As always, when damp is suspected then one must locate the source of the moisture. If the c/board is indeed "sweating" the moisture must have come from some where.
1. you can seal glass off-cuts, or any transparent material,to the asphalt and wait and see if condensation forms.
2. what condition was the original finished floor in?
3. why two layers of sub-floor?
4. are all the floors solid, or only the kitchen?
5. the asphalt was laid for a reason - typically to prevent damp by forming a membrane. examine it carefully for cracks, thinly smeared-on areas or penetrations. There's no typical depth, but 15-20mm is good.
6. any signs of damp in the kitchen walls? Does it smell musty?damp?
7. research on this forum for why damp presents in buildings, esp in solid floors.
8. it would be possible to lay a sheet membrane on the asphalt and float the new floor above it with no penetrations/fixings allowed. But try to determine causes first.
9. what kind of new finish flooring are you proposing?