DIY - Damp Patch!!

[mole]

Hi all

 

Wondering if any DIY'ers could advise on this problem.

 

having new carpet laid in hallway, so ripped up old carpet and underlay to reveal concrete floor.

 

now where the hallway concrete floor meets the living room concrete floor (covered in wood laminate) there is a length of very old oak wood about 4"x12" not sure whys its there.

 

anyway carpet chap covered it in screed to get it all level but now there is moisture coming through the screed all along the wood length - obviously it cannot stay there - so my question is would you dig out the wood beam and put some damp course in the hold and refill with concrete? or a few ventilation bricks?

 

I don't want the moisure coming up somewhere else? - do not want to be lifting up laminate flooring! - my guess is that under the wood beam is just soil (old old house)

 

anyway attached an awesome diagram of it if it helps. damp area is airbrushed in yellow

Edited October 5, 2015 by mole

[Smed]

on your diagram where you have marked your walls and door frame, what are the walls built from? are they solid walls? ie brick/block plastered....or are they partition walls? ie timber studwork/plasterboard...

reason i ask is if they are timber/plasterboard they could potentially be sitting on the old oak beam?? if you are certain they are not, and the old beam is in no way structual, then you could remove the beam to as much depth as you can, place some visqueen membrane down and then concrete/screed it back up,, the visqueen will then prevent and damp coming back up...make sure you have some soft sand beneath the visqueen to protect it from punctures when concreating....

if you can, get a good depth of concrete down (ideally 150mm)

Edited October 5, 2015 by Smed

[elsiegee40]

The problem is that wood "breathes"... sealing it in with "concrete stuff" could well mean that a piece of previously sound, and possibly structural, timber is now starting to rot. I think you need to free it and take a good look at what it actually does before making any more decisions

[mole]

thanks all....

 

wood was already a bit rotten - i'd hoped letting it breathe for a few weeks would have let it done it stuff but appears not

 

hmmm......will have to investigate - luckily have until the 21st before carpeters return.

Edited October 5, 2015 by mole

[Seb1780]

 

very old oak

 

 

about 4"x12"

 

 

old old house

 

 

That sounds structural, or at least it sounds like it was structural when first built.

 

If it's any consolation, it's probably always been damp, just that now you see it with the leveling compound in place to show it.

 

There is no quick fix, get a few specialists to look at it before you go any further.

[difinity]

It's a bit hard to be sure without a photo but it's possible the beam is part of the frame that was set into the concrete. If it was a little rotten then it would act like a sponge sucking up the water from the screed and the damp is the water slowly being released.

 

From personal experience i had to remove a similar beam (although much longer) which was the bottom part of the wooden load bearing wall, when i made my downstairs open plan. I had to chop it out and fill it with concrete and screed before laying my laminate. It didn't need membrane as there was concrete underneath.

 

I wouldn't make any decisions without an experts opinion.

[mole]

My plan is to (got a feeling wood is left over piece just used to fill a hole - not structural) remove wood - dig down - leave a void and putting this on top:

 

Rytons Multifix Interlocking Plastic Air Brick Ventilation 9" x 3" Airbrick Vent | eBay

 

At least then it has some chance of evaporating/controlling the moisture - its not a great deal of moisture coming up but overtime would build up.

[difinity]

Airbricks go in walls not floors.

 

There shouldn't be any noticeable moisture normally although concrete takes about 100 years to fully cure and all that you are seeing is the water that the wood soaked up from the screed.

 

If you are removing the wood, there should be concrete underneath. Do not dig down, just let it dry out. Then fill the hole.