Damp or roof!

[Jenny Holden]

Please can someone advise us on the mould shown in the attached photo? It is behind a fire surround that came with the house. The mould had also been either side of the surround but I have cleaned it. Could it be caused by the pointing on the damp proof course looking in poor condition. We had the wall re pointed but they appear to have left the row where the damp proof course is. Or from the roof? We do have leaks from the roof.

Suggestions greatfully recieved.

 

[Paul Cumbria]

Please can someone advise us on the mould shown in the attached photo? It is behind a fire surround that came with the house. The mould had also been either side of the surround but I have cleaned it. Could it be caused by the pointing on the damp proof course looking in poor condition. We had the wall re pointed but they appear to have left the row where the damp proof course is. Or from the roof? We do have leaks from the roof.

Suggestions greatfully recieved.

I assume from the photo that this is an old fireplace which has been sealed off and an electric fire installed instead?

If so the most likely cause is water ingress from the chimney. You say you have leaks from the roof - make that priority no.1 and get the roof seen to (and the guttering also). Whilst that work is ongoing, check the following:

1. Is the chimney capped? If not then rainwater will run straight down; there should be a cowl fitted to prevent this (and birds nesting), with ventilation to allow airflow.

2. Is the flaunching (mortar fixing the chimney pot in place) cracked/damaged. If the roof is in poor condition then this is very likely also. Worth checking the pointing on the chimney stack too.

3. What is the condition of the lead flashing where the chimney stack meets the roof tiles? Another common area of failure and water ingress.


I would strongly recommend having the chimney swept also; there is a very great probability that when the fireplace was sealed off, this was not done, and any old soot, birds nests etc lodged up there will harbour moisture as well as impeding airflow.

There does not appear to be a trickle vent fitted - this is vital to allow airflow up the chimney to prevent just this sort of problem - make sure you fit one with an insect screen! (I managed to fit air bricks in the void below the fireplace, allowing airflow up from the crawl space under my wooden floors so nothing to spoil the look of my nice new electric fire!).

Hope this helps!

 

[Jenny Holden]

I assume from the photo that this is an old fireplace which has been sealed off and an electric fire installed instead?

If so the most likely cause is water ingress from the chimney. You say you have leaks from the roof - make that priority no.1 and get the roof seen to (and the guttering also). Whilst that work is ongoing, check the following:

1. Is the chimney capped? If not then rainwater will run straight down; there should be a cowl fitted to prevent this (and birds nesting), with ventilation to allow airflow.

2. Is the flaunching (mortar fixing the chimney pot in place) cracked/damaged. If the roof is in poor condition then this is very likely also. Worth checking the pointing on the chimney stack too.

3. What is the condition of the lead flashing where the chimney stack meets the roof tiles? Another common area of failure and water ingress.


I would strongly recommend having the chimney swept also; there is a very great probability that when the fireplace was sealed off, this was not done, and any old soot, birds nests etc lodged up there will harbour moisture as well as impeding airflow.

There does not appear to be a trickle vent fitted - this is vital to allow airflow up the chimney to prevent just this sort of problem - make sure you fit one with an insect screen! (I managed to fit air bricks in the void below the fireplace, allowing airflow up from the crawl space under my wooden floors so nothing to spoil the look of my nice new electric fire!).

Hope this helps!

Hello Paul,


Thank you for your rely and suggestions.
I should have said in my plea that it isn't an actual fireplace!
The house is 25 years old built without a fireplace. Previous owners
installed a surround with electric fire. No chimney.
We have had a persistent leak coming in under an en suite window.
We have had roofers look and they all say that there is nothing wrong with
the roof. Water is running down the cavity I think. We cannot have our bed next to the wall
in case it gets damp. The mould behind and adjacent to the fire surround is new. Just in the last
weeks.

Kind regards,
Jenny.

 

[Paul Cumbria]

Ahh, OK, that's just me jumping to conclusions!

Well at least you know the roof is OK, which must be a big relief. And you know where water is leaking, so you can address that. A house of 25 years old may have been built with cavity wall insulation fitted so hopefully that won't soak up and hold in too much moisture; if CWI has been blown in since, it may well hold in moisture, wicking it across to the inner wall, and will prevent drying due to lack of air circulation in the cavity - I had to have it removed at a far greater cost than having it installed in the first place......

Good luck!