Advice needed regarding moisture on chimney in loft

PhilR · 5 Oct 2008

When it is raining I am seeing some dampness on the surface of the chimney in the loft. I've circled the problem areas in the picture below. These areas are damp to the touch and some moisture is visible (it seems to be running down the white marks).

Untitled

PhilR
5 Oct 2008
1

The blue arrow shows where I can see a little bit of daylight through the roof. I can't see any rain coming through here though.

The other side of the chimney seems to be dry.

I have also taken some pictures from outside (from ground level - I don't have any ladders). These show the same side of the chimney from the back:

Untitled

PhilR
5 Oct 2008
1

and front:

Untitled

PhilR
5 Oct 2008
1

The rest of the chimney within the house seems to be dry. There is a seldom used gas fire at the bottom.

Could one of the experts here give me some advice? Should I be getting a roofer to take a look?

Thanks,

Phil

noseall · 5 Oct 2008

the staining to the chimney pargeting looks consistent with seepage staining.

i wouldn't be surprised if the flashings were intact but the brickwork maybe needs re-pointing.

there may no dpc either.

PhilR · 6 Oct 2008

Hi noseall,

Thanks for the reply. I'm going to try and get a roofing guy to have a look this week.

How difficult a job is adding a damp proof course?

Regards,

Phil

SurreyRoofingEstimator · 6 Oct 2008

Well, as difficult as taking the chimney down to the required level, putting in a DPC then rebuilding the chimney, not so much difficult as expensive. As the chimney isn't that tall (being at the ridge line) it would prob be best as noseall says to repoint and maybe coat with a silicon based waterproofing paint.

nfield750 · 16 Nov 2009

Hi, Phil, here's my story below - looks just like yours, same size stack, but much more staining and water ingress. I'd be interested to know what came of yours

About a year ago, I noticed streaks of moisture, wet to the touch, coming down from where my single flue chimney stack goes through the roof (about 2 tiles down from the apex). A reputable roofing company replaced the flashing (£350), but the problem persisted and got worse. Soot and tar contaminated water was running down the faces of the stack in the loft. The chimney was wrapped in a tarpaulin as an emergency measure and I contacted 4 builders. The consensus was that the damp proof course had failed.

Small damp patches had started to appear on the chimney breast in the bedroom near the ceiling. I decided to stop using the stove for the time being. I also waited for the bedroom stained areas to dry and redecorated after painting the whole chimney breast with Zinsser BIN.

The whole chimney was rebuilt above roof level (£1,700), this time with two damp proof courses and with council building control checking the work.

Needless to say, 7 months later, I am now faced with leaking flashing again and the builder has been called back under the guarantee. At least this time the water is clear. I have a few questions

a) I would like to keep my wood burner, but am loosing the will to persist. I have heard mentioned, that once a chimney starts to leak, its best to have the whole thing removed?

b) I have test drilled the stack where heavily stained and the brick under the rendering appears dry and uncontaminated. Can I assume the the staining is surface only?

c) During heavy rain (before the current leaks appeared) and when the moisture content of the air is high, I have noticed that the stained areas become damp to the touch. Is this normal?

d) I have been told that the stove and chimney would benefit from a chimney liner, back filled with vermiculite. Is this a good idea?

Any advice would be appreciated

Untitled

nfield750
16 Nov 2009
2

Untitled

nfield750
16 Nov 2009
1

Untitled

nfield750
16 Nov 2009
2

marky101 · 12 Jan 2023

nfield750 said:
Hi, Phil, here's my story below - looks just like yours, same size stack, but much more staining and water ingress. I'd be interested to know what came of yours

About a year ago, I noticed streaks of moisture, wet to the touch, coming down from where my single flue chimney stack goes through the roof (about 2 tiles down from the apex). A reputable roofing company replaced the flashing (£350), but the problem persisted and got worse. Soot and tar contaminated water was running down the faces of the stack in the loft. The chimney was wrapped in a tarpaulin as an emergency measure and I contacted 4 builders. The consensus was that the damp proof course had failed.

Small damp patches had started to appear on the chimney breast in the bedroom near the ceiling. I decided to stop using the stove for the time being. I also waited for the bedroom stained areas to dry and redecorated after painting the whole chimney breast with Zinsser BIN.

The whole chimney was rebuilt above roof level (£1,700), this time with two damp proof courses and with council building control checking the work.

Needless to say, 7 months later, I am now faced with leaking flashing again and the builder has been called back under the guarantee. At least this time the water is clear. I have a few questions

a) I would like to keep my wood burner, but am loosing the will to persist. I have heard mentioned, that once a chimney starts to leak, its best to have the whole thing removed?

b) I have test drilled the stack where heavily stained and the brick under the rendering appears dry and uncontaminated. Can I assume the the staining is surface only?

c) During heavy rain (before the current leaks appeared) and when the moisture content of the air is high, I have noticed that the stained areas become damp to the touch. Is this normal?

d) I have been told that the stove and chimney would benefit from a chimney liner, back filled with vermiculite. Is this a good idea?

Any advice would be appreciated

Untitled

nfield750

16 Nov 2009

2

Untitled

nfield750

16 Nov 2009

1

Untitled

nfield750

16 Nov 2009

2

total long shot but did you ever get this resolved? We have EXACTLY the same issue that the previous owners obviously tried to fix with a bodge. had flashing redone, cap added, bricks sealed. still leaking

PLEASE POST A NEW THREAD. Mod

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Advice needed regarding moisture on chimney in loft

Similar threads