Damp wall

[rockhopper69]

I wonder if anyone can help , the internal wall of my sisters bay window is starting to get damp approximately were the mortar is missing from a couple of the external bricks at low level .
As can be seen on the pics I’ve noticed there appears to be 2 distinct damp patches on the path which seem to be tracking up the bricks . I think because the roof of the bay window doesn’t protrude past the window sill I think water is splashing off the sill and causing the damp on the path. The thing I don’t under stand is why is it just two spots and a pretty new problem , I will have to try and see it when it’s raining to check it is only dripping at them two points .
Will the dampness eventually soak through the places we’re the bricks are dark ? Could this be anything to do with damp course ?
Thanks in advance

 

[Ivor Windybottom]

Have a look the next time it's raining heavily. I'm wondering if the concrete has sunk at its adjoining edge so is actively funnelling two big puddles into the wall.

If so break it out and replace, ensuring there's a decent outwards slope, after compacting a layer of rubble thoroughly into the ground to hopefully prevent future movement.

 

[Ivor Windybottom]

I mean replace with new concrete, don't attempt to put the same slab back!

I'd smash it to pieces with a breaker drill, put the rubble aside, dig down deeper then put the broken old concrete back in and smash it down into the ground. On-site recycling, you'll just have a bit of surplus soil to get rid of. Then get some new concrete to make a new path.

 

[ree]

OP,
Someone could use a hose pipe to lightly spray the roof, & someone else could observe for gutter overflow and/or splashing? Check the gutters for blockage.
Pic #6 shows the DPC line just one brick above the ground level - it should be 150mm above GL.
The wall appears to be a cavity wall but water is still crossing to the inner skin?
Only one air brick that's been set too high can be seen - do you have a suspended bay floor?
Inside the bay the scotia moulding looks very dark in parts, dark can suggest damp, & the skirting has pulled away from the inside corner.
The bay brickwork has been re-pointed in the past - its wrong.
Pointing needs a 25mm deep rake out, and the use of 3:1 sand & NH lime mortar mix.

 

[Ivor Windybottom]

Cement mortar isn't "wrong"! It's what almost every house is built using. Lime mortar has become something of a religion, with its followers thinking cement was sent by the devil or something. Cement mortar is completely normal, please ignore someone on t'internet spouting stuff apparently from California(?).

The pointing's fine, don't touch it. The only reason it's popped out in one area is because it's got very wet.

I can't work out where the DPC is. It looks like it's two bricks up on the left, but the last photo shows one that's one brick up. Even that shouldn't be fatal though, not advisable but not enough of an issue to worry about.

The cavity may be bridged. But more likely it's just full of water, from the concrete tipping it all into the wall.

A hosepipe test would be a good idea, but a good downpour will do a better job of highlighting issues.

 

[JohnD]

The watersplash may also be caused by rain spilling off the bay. Please stand back and take wider pics, all the way up to the roof and gutters, and all the way down to the ground and paving, include downpipes and drains.

It's also possible that the concrete paving was added after the house was built, sloping to encourage water to run towards the wall and/or bridging the DPC. Sadly this is very common and there are still numbskulls doing it today.

Incidentally, lime mortar is washed away by persistent water leaks, leaving gaps between the bricks that may fill with mud, moss and weeds. The gaps can be cleaned out with a hose or pressure sprayer and packed with a stiff mix of sand and cement. Repair the source of water first.

 

[ree]

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