Could this damp be from the flashing around chimney?

[loziv]

Hi

We have just noticed in our daughters bedroom that where the exterior wall and the chimney breast join there are damp patches as shown in the picture

Could this be caused from the flashing around the chimney or could it be something else?

The walls in this part of the house are timber frame and clad with tile to the outside, none of the tiles are missing on the exterior wall

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• loziv
• 19 Feb 2014
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• loziv
• 1 Apr 2012
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• loziv
• 1 Apr 2012
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[HERTS P&D]

In the last picture it looks like the soffit is mostly missing?

This could be due to a leak above?

Andy

 

[loziv]

Hi

I think that's just the pic the soffits are in place they are the old asbestos style soffit

 

[noseall]

Look at or google 'hygroscopic salts contamination'.

 

[loziv]

Thanks so do you think it might be hygroscopic salts contamination. And if it is where do you think the water ingress is coming from the chimney or through the actual shingle tiles on the wall?


As looking in the loft where the chimney is I cant see any damp patches, although with the position of my chimney I am unsure if you would?

 

[noseall]

Hygroscopic salts will pull the moisture out of the air.

Let's not forget, most occupied domestic homes are bursting with humidity.

 

[loziv]

So what would be the solution put a dehumidifer in the room? How do I get rid of the salts?

 

[noseall]

So what would be the solution put a dehumidifer in the room? How do I get rid of the salts?

You can't get rid of the salts as they are in the masonry.

They can be prevented from leaching out by means of SBR slurry coatings and SBR render. This of course would mean hacking the existing plaster back to brick.

 

[loziv]

The internal walls in this part of the house are not brick/masonary as this section is timber frame?

And its strange how only now it has started to appear especially after all of the torrential rains we have had over the past few weeks.

I painted the bedroom before Christmas and sanded the wall/paint down and painted a mist coat over the area where this problem was and now it has started to reappear?

 

[noseall]

What, so none of that chimney breast is in direct contact with the room plaster?

 

[loziv]

Yes it is sorry where the chimney breast joins the wall as shown in the pic, which is where the damp patches are.

The chimney breast though looks as though it has been clad by plasterboard as when tapping the chimney breast is sounds that way?

Can these salts cause any long term problems is unresolved?

 

[ree]

If you look up to the top courses of the stack, they appear to be darkened - perhaps by soot and salts coming from the flue to the brick surface.

Or, maybe rainwater seeping down from the flaunching.

If a solid fuel fire has been used and the flue(s) has not been swept, then the internal salts suggestion given above could be the answer.
Especially, if the fireplace(s) has been blocked and the flue isn't vented.

Difficulty with this suggestion is that the finished surfaces are standing off the brickwork.

However, pic 3 shows staining on the soffit and a possible missing cover flashing above the gutter.

Pic 3 also shows stained brickwork, and tile hanging, in the top corner below the soffit.

With the guttered fascia running past the stack, it makes for a flashing detail that could only be resolved by viewing from a ladder.
From a ladder all the stack flashing should be inspected.

Raising a ladder to inspect the flaunching requires caution given the unsupported height of the slender stack.

 

[loziv]

Would removing the chimney stack solve the problem?

 

[ree]

You dont yet know what the problem(s) is.

Find the cause and then take decisions.

 

[loziv]

We have had a roofing contractor around today who advised it would be better to remove the chimney as this is the cause of the water ingress rather than just relead the chimney etc as the cost differential would be miminal and if the chimney is removed then there can be no further issues with water ingress