Large rock issue. Will it give use floor/plaster problems?

[wertert]

Hi All


We have started work on a battened wooden floor and UFH on a concrete slab and have discovered a small issue. There appears to be a large rock located at this end of the room which is possibly part of the foundations. The concrete slab has been formed around this rock. There also appears to be a vent to the outside along side this stone. This was probably there to vent the old timber floor void.

The question is do you think I need to do anything special with the new floor in this area ? I thinking the vent/airbrick isn't a bad idea as we are required to have one for the wood burning stove. Does this count if it's below the floor ?

My main worry is are we likely to get damp in the floor construction ? Are we better off just filling in the vent and vandexing the whole area. I'm going to attempt to upload a few pics. I've also just noticed that we have some discolouration of the plaster above the stone i.e tide mark. You can see this in the pictures. Can't say i've ever seen the plaster damp etc.

I've loaded a few pics to a diynot album

//www.diynot.com/network/wertert/albums/6849

Thanks in advance.

J

 

[JohnD]

if you mean this picture

Untitled

• wertert
• 19 Oct 2010
• 1

it doesn't look like a rock to me, it looks like concrete.

And in the picture it seems to be a concrete floor because I can see the plastered wall meeting it. I can't see a subfloor void.

 

[joinerjohn]

Re-read the OP John. He does state that this used to be a timber floor before the concrete slab was laid.

 

[mointainwalker]

I'm almost certain the underfloor vent won't be accepted as vent for the stove unless you make a direct piped-connection from the brick up into the room .

It would be just be too easy for it to be forgotten, carpets laid etc. otherwise, would it not ?

 

[wertert]

I'm almost certain the underfloor vent won't be accepted as vent for the stove unless you make a direct piped-connection from the brick up into the room .

It would be just be too easy for it to be forgotten, carpets laid etc. otherwise, would it not ?

I think you're right. We are intending to lay floorboards over this area. They run towards the rock and are sitting on 45mm battens. The boards will terminate 10mm from the stained plaster and we will also fit a skirting above.

I'll add another picture to make things a bit clearer. The should now be 4 pictures in the album

//www.diynot.com/network/wertert/albums/6849

 

[JohnD]

ah, I see what you mean.

the plaster does have a bit of a tide mark, you might consider zipping the plaster off for the first 100mm (or depth of your skirting) to expose the bricks. If you put battens on the wall to fix the skirting to, it will look perfectly neat, and damp will not rise up so easily. Treat the battens against rot.