Damp / wet floor in outbuilding joined to house

[mr_king]

I have a handy little 10x8 brick built outbuilding joined onto the kitchen, to which i have just laid some ceramic tiles on the floor.

Recently i have noticed the floor being damp to almost wet along the edge of 2 walls right along the edge to corners of the walls.

I have check the walls outside and there is not high points of soil against the wall, infact the garden outside is concreted.

I cant notice any damp proofing on the outside brickwork but then there is a black concrete plinth running around the bottom of the brickwork.

I really want to get the room decorated and in use but dont want to do it until this damp problem is solved.

Any ideas or suggestion on where the moisture could be coming from would be welcome.

Thanks.

 

[Softus]

If the outbuilding had no DPM lapped into a DPC, then there would have been moisture within, and around the perimeter of, the floor slab.

Since you've just sealed off a path for that moisture to emerge, I would expect it to rise between the edge of slab and the wall.

If this is what's happening, you need to take up your tiles, break up the slab, and re-do the job properly with a DPM.

 

[AdeF]

Alternatively you could ask a specialist damp-proofing company to look at this for you - you will no doubt still lose your tiling but they may offer a cheaper solution than breaking up & renewing your floor slab?

 

[Softus]

Alternatively you could ask a specialist damp-proofing company to look at this for you - you will no doubt still lose your tiling but they may offer a cheaper solution than breaking up & renewing your floor slab?

Please explain what advice a damp-proofing company is going to give, other than to recommend buying their own products and/or services.

 

[AdeF]

Please explain what advice a damp-proofing company is going to give, other than to recommend buying their own products and/or services.

Undoubtably they would, but this may prove cheaper & less disruptive than breaking up and renewing the complete floor slab.

 

[Softus]

Cheaper and less disruptive is pointless if it doesn't solve the problem.

Perhaps I was mistaken in thinking that he wanted to actually stop the damp, rather than spend some money on pretending to stop it.

 

[AdeF]

Pretending to solve the problem would be kind of pointless.

Application of an effective tanking system or similar which stopped the damp from reaching the inside of the building, damaging finishes, timber etc would be far from pointless.

 

[Softus]

Application of an effective tanking system or similar which stopped the damp from reaching the inside of the building, damaging finishes, timber etc would be far from pointless.

You've as much chance of finding one of those as you have of getting one of these to appear and magic the damp away.

 

[Monsoon]

Does the rain water flow away from the building?

A small slope towards the building could result in rain water collecting and being absorbed.

If you need to tank the room, have a look at how to contruct a wetroom. They use very thin membranes so you wont need to raise the floor height very much and wont require much prep on the existing floor.

 

[Softus]

Tanking in this scenario would be like putting sellotape on a fatal stab wound.

 

[Monsoon]

Tanking in this scenario would be like putting sellotape on a fatal stab wound.

A well Tanked floor/walls eliminates the need to dig up the floor. It hardly analogous to celotape. More like Duct tape on steroids

 

[Softus]

A well Tanked floor/walls eliminates the need to dig up the floor.

That's odd, because in my outhouse, which isn't tanked, I've eliminated the need for tanking by not having a whole bunch of water underneath the floor.

In your opinion, after tanking, what will happen to the water/moisture that is currently appearing in the OP's floor?

 

[Monsoon]

A well Tanked floor/walls eliminates the need to dig up the floor.

That's odd, because in my outhouse, which isn't tanked, I've eliminated the need for tanking by not having w whole bunch of water underneath the floor.

In your opinion, after tanking, what will happen to the water/moisture that is currently appearing in the OP's floor?

There is always moisture in the ground, the tanking stops the moisture affecting the floor covering.

 

[Softus]

In your opinion, after tanking, what will happen to the water/moisture that is currently appearing in the OP's floor?

There is always moisture in the ground, the tanking stops the moisture affecting the floor covering.

Is your post supposed to contain an answer to the question in my post?

 

[Monsoon]

That's odd, because in my outhouse, which isn't tanked, I've eliminated the need for tanking by not having a whole bunch of water underneath the floor.

Where do you think your water has gone? All you have done with a DPM below a new slab is created a barrier, that's what tanking does.

It's better to have DPM below the concrete slab but providing the moisture content is within the manufacturers allowable limits then no problem applying over the top.

OP have a look at the Liquid DPM sticky in flooring section on this site.