DPC Problem

[Farm1953]

My builder has retrofitted a physical dpc in internal walls but has used 100 mm dpc over old bricks which are 110mm wide. 5 mm at each side of brick not covered.
Will this still allow damp to rise? If so, what are the solutions? My builder won't redo it.

Thanks for any advice.

 

[Bonni]

The builder will have to redo or rake out the mortar back to expose the dpc without damaging the dpc, then never bridge that gap with wood, plaster, brick, gravel, stone etc..

Doesn't sound to be a competent builder.

 

[foxhole]

My builder has retrofitted a physical dpc in internal walls but has used 100 mm dpc over old bricks which are 110mm wide. 5 mm at each side of brick not covered.
Will this still allow damp to rise? If so, what are the solutions? My builder won't redo it.

Thanks for any advice.

Damp falls , does not rise .

 

[Lower]

Damp falls , does not rise .

Why have i got a damp patch in a single skin internal wall where both sides are exposed, there are no leaks above ground and there's damp on both sides up to about 300mm either side then?

 

[foxhole]

Why have i got a damp patch in a single skin internal wall where both sides are exposed, there are no leaks above ground and there's damp on both sides up to about 300mm either side then?

I don’t know your property so difficult to know with zero information .

 

[Bonni]

Why have i got a damp patch in a single skin internal wall where both sides are exposed, there are no leaks above ground and there's damp on both sides up to about 300mm either side then?

Damp can rise 1.2m, dpc should never be breached. Ignore foxhole.

 

[Harry Bloomfield]

Damp can rise 1.2m, dpc should never be breached. Ignore foxhole.

Correct! The damp course should never be covered/incontact with anything which is absorbent, such as cement or plaster. If the DPC is to be behind skirting boards, then the plaster behind the skirt, needs to be removed.

 

[RayCaister]

Damp falls , does not rise .

I remember the documentary on TV -- Rising Damp .

 

[foxhole]

Damp can rise 1.2m, dpc should never be breached. Ignore foxhole.

No case of rising damp has ever been proven , £10,000 reward for proof still remains unclaimed.

 

[JohnD]

My builder has retrofitted a physical dpc in internal walls

How did he do that? Cutting a slot along the wall through a mortar joint?

Where do you think the water is coming from? A leaking pipe in the floor?

 

[JohnD]

Why have i got a damp patch in a single skin internal wall where both sides are exposed, there are no leaks above ground and there's damp on both sides up to about 300mm either side then?

Post some photos, of the entire wall, both sides, showing the shape of the damp patch.

Is it a concrete floor?

 

[Harry Bloomfield]

No case of rising damp has ever been proven , £10,000 reward for proof still remains unclaimed.

Anything hygroscopic, such as plaster, or timber, in contact with moisture, below a DPC, and bridging it, can allow that moisture to spread up hygroscopic materials on that wall, such as the wall plaster. Bridging of the DPC, being the most common cause. Having said that, most damp and mould is not due to rising damp, but to other causes. Blaming DPC failure, is a favorite MO of many companies, claiming to provide an expensive fix for DPC failure.

 

[foxhole]

hygroscopic refers to material able to absorb moisture from the air only.

 

[Harry Bloomfield]

hygroscopic refers to material able to absorb moisture from the air only.

No, from the local environment. What word would you have used?

 

[foxhole]

No, from the local environment. What word would you have used?

No idea what you are trying to say .

But
hygroscopic

1. (of a substance) tending to absorb moisture from the air.
   • relating to humidity or its measurement.