Random Damp patches

[mylittlehouse]

Hello all.
I'm after some advice if poss.

I have some random damp patches in the corner of my chimney break in the ground floor.
They are about 1.8 meters up and I have checked the room above and there is no damp coming from above as the wall directly above in the bedroom is bone dry.
The is rising damp below and this will be fixed by injections over the new month or so.
Can anyone thing of where these Random patches are coming from.
?
Thanks all

 

[^woody^]

It's either condensation from the flue, or penetrating damp. Its too high for rising damp

 

[KenGMac]

Hi.

Several points.

1/. is there a vent in the room where the fireplace was blocked up?

2/., is there a vented cap on the chimney pot?

If no to one or both of the above then you may have condensation occurring in the old flue, or in the case of chimney head rain water could be entering there and dripping into the flue to come to rest at the ground floor level.

as an aside rising damp is considered not to occur above 1.0.m. capillary attraction can not sustain the weight of water above this height

Is the chimney head in good condition above roof line ? if rough casted is it all still there ? if brick or masonry [stone] are the joints in good condition ? If not this is where the rain is getting into the flue.

What may be happening is that the rain water is dripping down the flue, the only thing at ground floor is a lintel that will possible protrude into the flue and on to which the rain can drop and gather, causing random damp patches.

 

[mylittlehouse]

Hi there thanks for your reply.

Basically there was a Gas fire installed in the opening that has a small flue but the room has a draft anyway. ( i have removed the gas fire and will put ni a log burner)
The chimney has a normal pot on top.
Right next to the chimney stack is a window and this never has condensation on it so far and we have been here a year.
Weird thing is above the stack where the damp is in the bedroom above there is no stack as the one upstairs is not as wide as its a bedroom one so it only seems to be in the downstairs stack.
i have removed the paper from the bedroom above and cannot find any damp and have checked the pointing.
Maybe that corner is getting some condensation or has in the past.
today i will have the company out who installed my DPC injections into my living room look at doing the same into the next room i will ask for a reading today to make sure its not just me.

Thanks

 

[^woody^]

Condensation from within the flue, not condensation from the room

 

[HERTS P&D]

Do you have a dog?

Andy

 

[catlad]

I would not do anything regarding dpc until after you have installed the woodburner as these problems will go away with a working chimney.

 

[mylittlehouse]

Hi there
I do have a dig but he does not go upstairs.
I never knew you could get condensation from the flue.
As for the DPC i have to get this done anyway as the damp problem was originally caused by next door bridging the original damp proof cource with a driveway and also a wall that has been built next to the house that porces water down the wall.
the whole corner needs attention before i think about plastering.
i was just worried as there was some heigher up.

Thanks