What Should I Do With This Damp Wall?

[subzero]

Hi all,

Looking for some advice on this external wall.

It's an old chimney breast which has been capped off by a previous builder, lintel installed about 3/4 up the wall (behind the plasterboard in the photo), and a recess was built into the chimney breast just underneath that. Although this could actually be bricked up, as not required.

The plasterer boarded over most of the entire wall, but then had to pull the centre section out as it was bowed, because by some of the brickwork in the lower area was standing proud of the rest (now chiseled back to resolve).

It's ready to be re-boarded in that area.

However, we noticed damp in the brickwork below the recess. A slurry mix was applied but the damp seems to be getting through in areas where the brickwork mortar is.

Questions I have are

1. What could be causing the damp?

2. What is the best solution for this wall going forwards?

 

[Ivor Windybottom]

It's the rain, getting into the chimney above.

Is the chimney all yours, or shared with a neighbour? You could muck about with draughty ventilation, cowls and flashing. But my preference would be to take it down if it's disused and roof over where it currently is. If shared then ask your neighbour if they'd like to go halves. It's a fairly major but not horrendous job. It needs scaffold, but once done it's a huge source of future problems permanently gone.

If you get it down below the roof you then have the option of removing it from the top down, either now or later, making rooms upstairs bigger and continuing down as far as you like. You could end up just removing the whole lot if you like. Although there's no harm in leaving the bottom of it there if you don't want the disruption all at once. Once it doesn't go out of the roof it will stay dry.

 

[subzero]

It's the rain, getting into the chimney above.

Is the chimney all yours, or shared with a neighbour? You could muck about with draughty ventilation, cowls and flashing. But my preference would be to take it down if it's disused and roof over where it currently is. If shared then ask your neighbour if they'd like to go halves. It's a fairly major but not horrendous job. It needs scaffold, but once done it's a huge source of future problems permanently gone.

If you get it down below the roof you then have the option of removing it from the top down, either now or later, making rooms upstairs bigger and continuing down as far as you like. You could end up just removing the whole lot if you like. Although there's no harm in leaving the bottom of it there if you don't want the disruption all at once. Once it doesn't go out of the roof it will stay dry.

Many Thanks for the quick response

It's detached so no issues there. Just trying to understand why the damp only presents itself in that area, and not further up?

The room above is a newly refurbished bathroom; taking it down further than below the roof level would have a major impact, not least cost-wise!

 

[Ivor Windybottom]

It's detached so no issues there. Just trying to understand why the damp only presents itself in that area, and not further up?

Gravity. It's wet where the water is sitting, it may be an inch-wide trickle all the way down, having negligible effect or none at all if it's on the outer side, then it sits and spreads at the bottom.

If you could make use of the extra space downstairs then don't rule out doing things in the bathroom above - it could be worth it. It depends how much impact it would have on the layout.

We have two disused chimneys that are roofed over. I'm not going to bother removing either within the building, just glad to have got rid of the leaks every time we got heavy rain. We have chimneys that end just under the roof in the loft.