Multiple chimney damp help required

[Don10]

Hi,

The property is Victorian, over 3 storeys high with 2 capped and unused chimneys at this level with the third at first floor level.
There is damp causing problems internally on and around each chimney breast.
Measures taken so far include flash banding the base and coping stones of the gable end chimney and flash banding around the base of the other high level chimney. Also cracks in between coping stones and chimney caps have been cemented. These repairs have made matters worse.

Are new lead cappings and soakers necessary as well as patch pointing and silicone spraying of the chimneys or is replacing the lead flashing around the chimneys + pointing + silicone likely to be sufficient?

Finally is there a way to minimise the need for frequent gutter cleaning considering the height of the property?

 

[roofer1uk]

Hi, Mate. Chimneys arn't always obvious proplems and can be a nightmare to diagnose . The only way is to get up and check leadwork (remove slates to inspecct soakers) apron, back gutter, Pointing and condition of flaunching, pots and cowels. cracked flaunching can be a major cause of damp.

it's probably in general bad condition so i would advice redoing all the leadwork, pointing and flaunch to give you years of trouble free winters,

for your gutters try these.......

http://www.toolstation.com/shop/p91940

 

[Don10]

Thanks mate, I had a feeling I'd need to get more repairs done than I would have liked.

How easy is it to remove and replace those guards for maintenance?

 

[roofer1uk]

Thanks mate, I had a feeling I'd need to get more repairs done than I would have liked.

How easy is it to remove and replace those guards for maintenance?

They are just held in by the flexible plastic sides of the guard so pull out really easy.

 

[big-all]

how are the stacks ventilated at the top and in the rooms at the bottom ??

 

[Don10]

how are the stacks ventilated at the top and in the rooms at the bottom ??

Not at all as they are unused and capped due to birds. Would vents really make that much difference?

 

[big-all]

yes of course moisture will enter at one or more points for what ever reason
it then has no choice but to collect on ledges and surfaces down the void and the moisture builds up until enough to penetrate the walls is there

vent at the top and bottom air flow removing the damp air before it builds up and penetrates where its not wanted

think off it as a door mat in the porch it reduces mud and water because you leave your shoes there to save the rest off the house with a lot off snow you will have to clean the matt
in the chimnie the matt = the vents removing the damp from where you dont want it with no effort

now if you want to save draught the place the vent on the outside wall but off course a bit off controlled ventilation in every room is extremley helpful to reduce condensation

 

[Don10]

Ok I had this work done in March 2011. However even during a warm summer and now with the property occupied and regularly heated there are still damp patches in the same places.

The contracted builders say that I need to replaster. But bearing in mind that the walls tend to stain worse during wet weather is their opinion reasonable?

 

[cotswoldbuilders]

Check all lead work, including soakers, flashings, front and back gutters.
Check all mortar pointing and flaunching.
Fit Bird/ rainguard cowls, to vent chimney pots, and if sealed up inside fit vents.
Check for any broken tiles/slates.

 

[Alastairreid]

High and low vents! crucial.

 

[BethesdaSlate]

As above, it is essential the chimney is vented.

 

[Don10]

Thanks for the replies. The chimneys have been reflashed and pointed and vented since March. According to the builder, the chimneys and roof are sound and it is the plaster that needs redoing for the reason outlined below. In the short term I've had to use damp seal paint, however if water is still getting in it will still cause damage. In any case I'll have it checked again.

I've read that residual salts in plaster can cause recurring problems if previously damp walls are not replastered and wanted to include or exclude this possibility.

 

[Alastairreid]

Dont forget you need vented terminals on top of the redundant pots and vented grills at each bricked up fire opening.
Air circulation to the flues is needed to expel the continuous water ingress from the unused stack which acts like a giant sponge.