joist by constructional hearth - do I have a damp problem?

[gtgt]

Hi folks
getting ready to lay a laminate floor in my new house, and have just finished removing the mother of all stone hearths (it was massive).

I've dug down into the constructional hearth and found some bricks used to go around the the sides of the hearth under the floor (which was filled with, well rubble) - these bricks are damp (as they're in contact with the hearth) and have been in contact with a joist. Where they've been in contact, the wood is a bit damp (not soaking but wet enough to smudge the dirt on my fingers) and a little bit soft (I can push my fingernail in a bit) compared to the rest of the joist. There is some white residue on the joist (maybe efflourescence from the bricks? the same stuff was on the bricks also)

If I leave it to dry out, will it be OK, or will rot ravage everywhere The hearth feels (and smells) a bit damp, but obviously there was no air flow over it. Are there any preservaties I could use just to make sure?

Or another note, should I put a dpc in and fill up the hearth with concrete, or try and span some timbers over it for the new floorboards?

Cheers everyone! Will put some images up (apologies for quality, had to use my phone)

 

[gtgt]

This is what I found. Here you can see one of the bricks used to create a frame of bricks around the sides of the constructional hearth. Some of the bricks were in contact with the joist (I've taken one out here)

Untitled

• gtgt
• 16 Oct 2010
• 1

Here I've removed all the bricks, you can see the white stuff (efflourescence?) and the little patches of damp (darker patch)

Untitled

• gtgt
• 16 Oct 2010
• 1

Untitled

• gtgt
• 16 Oct 2010
• 1