Damp Patches on chimney breast.Pic included.

Jon_Tiffany

We had damp problems due to flashing on the chimney, I think it may well be rain running down the liner to the bottom, hence the damp patches appearing so low.

I dont think its problem with the DPC, as others have said it would likely appear elsewhere. Check the outside ground level is not high and causing the DPC to be breached, this is a very common problem, especially with pathways as they tend to get layers built up (cheap tarmac jobbies mainly).

As for drying it out, I recently suggested using a dehumidifer on another thread. This website has all the info you need on them, we have been using one ever since we had our damp problems to keep the house dry.

Some spot heating on the patch will help dry it out even faster, but until you find the cause of the problem its likely to keep coming back. I'm afraid it may also damage the plaster if you dont find the cause soon.

Have you checked for leaking pipes under the floor?

Dry_Rot

Hi,

bear in mind that this is a bricked-up chimney face - the original fireplace probibly had a hearth.

So, it is likely that:

1 - the new plaster below the mondernised fireplace is in contact with the concrete hearth and is bridging the DPC, or

2 - there is no DPC in the new brickwork or it is bridged by the hearth or debris in the bottom of the stack, or

3 - bricks from the old fireplace were re-used and they are full of sulphates and nitrates and these have eventiually migrated through the gysum based plaster.

or, eh...something else.

leveller2911

Dry_Rot wrote: »

Hi,

bear in mind that this is a bricked-up chimney face - the original fireplace probibly had a hearth.


I thought that until I looked at my fireplace which originally had a back bolier so ours didn't have a hearth and its about 8" or 200mm from the floor.Many fires with back boilers are a good few inches off the floor.

sophieschoice

I had the same problem years ago in another house. Turned out the builders had laid new asphalt floors and not left a gap between floor and skirting boards.
We had to vacate the house and have all the floors taken up!

stattman

Hi,

Not much help, but only to say I have the same problem.

I had a gas fire fitted around 5 years ago, after a back-boiler was replaced.

The chimney had a cowl -fitted and I've noticed this for last few years.

A friend told me it wasnt damp (he's abuilder) and just advised to paint it and not worry

Strange...

karl-123

you cannot just fit any cowl to a chimney,
there are several different types,
if you have got the wrong type,
i would cap off your fire immediately,

get a professional gas installer to service it,

i probably would not service your fire, as i do not like
the look of the installation,
the draught divertor is restricted and the fire looks like one
of those.........cheap focal point......things,
no offence karl....

rcandeias

My house is a mid terraced house and when it rains I hear dripping inside the chimney breasts on both sides (as i have two chimneys) I have had the cowels replaced and the workman stated that previous cowell was to small for the whole in the chimney and they had put some slates wedged so that the previous cowel wouldn't fall into the chimney.... Having said that with the right fitting cowell I still have the dripping sound in the chimneys when it rains ...although less of it still is there, and damp patches around chimney breast are still present on the ground floor even though I had plaster redone it just reappeared, no the chimneys are on the adjoining wall with the neighbour so normal raising damp is of question unless is rising damp as result of the dripping soaking the bottom debris in the chimney and rising through the brickwork.

I am unsure how to fix this, should I have someone up top resealing all the chimney (around the cowells etc) should I just cap the chimney ... should I just remove plaster paint brickwork with damp seal and then re-plaster...... please help with tips and hints or whatever...I need help bear in mind money is tight.

Regards

Ricardo :money: