Damp cold spots on plastered walls

[tonyslater76]

No windows don't have any vents.

I am not a builder so have no idea whether I can apply any procedure myself. The builder I used is not interested in this anymore. To dry line ? - not sure what that is. Is it a matter of putting up boards to insulate ?

 

[barnettgs]

If the wall you described is old but it has been recently rendered and plastered then you should read this: http://www.heritage-house.org/pages/managing-damp-in-old-buildings.html

Because it is the cement render and modern plaster that trap moisture in the wall, causing the damp to builds up. There is really nothing wrong with the wall, just that modern building materials are not suitable for it.

 

[joe-90]

Don't be silly.

 

[noseall]

If the wall you described is old but it has been recently rendered and plastered then you should read this: http://www.heritage-house.org/pages/managing-damp-in-old-buildings.html

Because it is the cement render and modern plaster that trap moisture in the wall, causing the damp to builds up. There is really nothing wrong with the wall, just that modern building materials are not suitable for it.

Utter tosh.

It is a simple as cold bridging via the dabs and the internal moisture condensing on cold days.

What that wall needs more than any venting or whatever else, is INSULATING.

 

[barnettgs]

What that wall needs more than any venting or whatever else, is INSULATING.

It doesn't work this way and it is very expensive and time-consuming as well, for a solid walled building.

I have a house with old solid walls that did not had a damp problem until after a major extension and renovation in '85 and that was damp-proofed as well, which has never worked since then. As a result, the house feels colder than it was before a major renovation.

...internal moisture condensing on cold days

Of course, this moisture has nowhere to go, isn't it?

 

[Alastairreid]

Bit of cross purposes going on here!

barnettgs this thread is about a single skinned wall with dot dab plasterboard not a 600mm random rubble lime plastered construction.

 

[barnettgs]

barnettgs this thread is about a single skinned wall with dot dab plasterboard not a 600mm random rubble lime plastered construction.

Ok, this can also be applied to any building with old non-cavity walls, not just rubbled solid walls.

Also from looking at OP's photos, the damp/moisture seems to have passed over from the wall which is wet not only because cement render has been used on outside side but also inside wall has not been dried up. Note OP mentioned that some brickwork were still wet when the plaster was applied on and with inbreathable cement render applied outside, there is NO other way for the wall to breathe (to dry), unless the cement render is removed!

Fitting air vents/brick or insulating the wall will NOT solve the problem because as long as the wall inside is wet, the damp patches will stay regardless. Anyhow, I think dot dab plasterboard is not meant to be used on a damp wall. If you still think this is utter tosh, thats fine I will refrain myself from any further posting on this thread.

 

[JohnD]

Fitting air vents/brick or insulating the wall will NOT solve the problem because as long as the wall inside is wet, the damp patches will stay regardless. Anyhow, I think dot dab plasterboard is not meant to be used on a damp wall but I will not post any further from this thread.

In your opinion, where is the water coming from?

 

[barnettgs]

Fitting air vents/brick or insulating the wall will NOT solve the problem because as long as the wall inside is wet, the damp patches will stay regardless. Anyhow, I think dot dab plasterboard is not meant to be used on a damp wall but I will not post any further from this thread.

In your opinion, where is the water coming from?

Did you not read that the wall was already wet? It can come from any source such as ground, the water will always find its way in, regardless of damp-proofed or not.

 

[Alastairreid]

You are correct dot n dab is inappropriate for a damp wall!

But in this case the problem is being caused by cold bridges from the dabs which is then causing moist air to vaporize on the cold spots..

 

[JohnD]

Did you not read that the wall was already wet? It can come from any source such as ground, the water will always find its way in, regardless of damp-proofed or not.

So, in your opinion, where is the water coming from? Do you not believe in evaporation? Did you not believe what he said about the dehumidifier?

You have looked at the pictures. Do you believe that those damp patches have risen up from the ground?

 

[barnettgs]

Did you not read that the wall was already wet? It can come from any source such as ground, the water will always find its way in, regardless of damp-proofed or not.

So, in your opinion, where is the water coming from? Do you not believe in evaporation? Did you not believe what he said about the dehumidifier?

You have looked at the pictures. Do you believe that those damp patches have risen up from the ground?

He has already used dehumidifer but it still doesn't help. Without plasterboard in between, it might help but with the covering of plasterboard, how can inside wall be dry? It's not a rocket science to work out, isn't it?

 

[JohnD]

Let me just check
You won't say where you think the water is coming from.

How do you think you can cure the damp without deciding on its source?

Do you agree that the walls will be very cold?

Do you agree that the OP has sources of heat and moisture in the room?

What do you think the wet patches look typical of?

 

[barnettgs]

Did you not read that the wall was already wet? It can come from any source such as ground, the water will always find its way in, regardless of damp-proofed or not.

Do you believe that those damp patches have risen up from the ground?

Did I say it was caused from the ground? By then, why was the wall wet? You figure it out.

Look guy, I can't be bothered to carry on posting in this thread so good luck in helping this OP out.

 

[JohnD]

Did I say it was caused from the ground?

Who can answer that question?

It can come from any source such as ground, the water will always find its way in, regardless of damp-proofed or not.