Damp around both chimney breasts!! AGAIN!!!

[Hullstorage]

Hi all,

We have a through lounge that has 2 chimney breasts, these both suffered from damp.

There was about 4 ton of rubble under the floors from the wall that separated the 2 rooms (this had been dumped under there by previous builders at some time).

Having cleared out all rubble thus creating a better air flow we was hoping this would have solved our issues which it has in most places apart from the 2 chimney breasts.

Somebody suggested capping off the unused chimney breasts as they think this could be causing the damp.

Would the chimney breasts not being capped cause these problems or is there something else i should be looking for.

Was thinking of injecting with DPC cream also?

The damp is at the bottom of the wall between and at the side of each chimney breast.

Thanks

Simon

 

[big-all]

i assume you have a vent at the base[if enclosed] and ventilation at the top ??

 

[Alastairreid]

Would the chimney breasts not being capped cause these problems

Yes! there should be vented caps on the redundant stacks and ventilation below.

 

[Hullstorage]

Not at the moment but there will be soon as we are in the middle of doing so.
could this be the actual cause of the damp and somebody advised using a repellent plaster in these areas if so any ideas what it is?

Thanks

Simon

 

[joe-90]

Capping chimneys makes it worse. Take a look at the millions of open chimneys and ask why they don't have damp walls.

 

[JohnD]

a disused chimney has to be vented top and bottom or it will get condensation. Sometimes you can have the lower vent under the floor, which reduces draughts in the room, and can also improve airflow in the underfloor void through the airbricks, which helps it stay dry

p.s.
there is a chance the old fireplace might be filled up with builders rubble. It will make damp worse. You will find out when you cut the vent.

 

[Alastairreid]

Capping chimneys makes it worse. Take a look at the millions of open chimneys and ask why they don't have damp walls.

Vented caps!

 

[joe-90]

Not those silly things that look like a flying saucer.

 

[joe-90]

a disused chimney has to be vented top and bottom or it will get condensation. Sometimes you can have the lower vent under the floor, which reduces draughts in the room, and can also improve airflow in the underfloor void through the airbricks, which helps it stay dry

That's a good tip.

 

[stevethespreader]

a disused chimney has to be vented top and bottom or it will get condensation.
p.s.

not necessarily so i have a disused chimney in my house without any vents and not one sign of damp it must have been covered for over 20 years or more

 

[Alastairreid]

Not those silly things that look like a flying saucer.

Excellent devices to aid the dissipation of condensation through chimney breast apertures.

Untitled

• Alastairreid
• 17 Jul 2009
• 20

 

[peaps2]

Capping chimneys makes it worse. Take a look at the millions of open chimneys and ask why they don't have damp walls.

Vented caps!

are no good unless you vent from below as well

Yes I done my day worth of work today Some of us are on site while others are still dribbling into their pillows

 

[joe-90]

Not those silly things that look like a flying saucer.

Excellent devices to aid the dissipation of condensation through chimney breast apertures.

Untitled

• Alastairreid
• 17 Jul 2009
• 20

Those things are rubbish.

 

[gasbanni]

I'm assuming the two chimney breasts have been bricked up ?

If they have its condensation building up because you have a slug of cold air in the stacks when the house is warm condensation builds up on the inside of the flue and eventually comes through as damp.

Put vents in let the stacks dry out and next summer cap and seal the stacks at the top then you wont need air bricks.