Water leaking, Wall or roof? help me find it

stuart45

A lot depends on what was used, how it was installed, were stop ends put on, weep holes put in etc. Unfortunately quality control in the building trade is much lower than a factory. Over the years, if the weep holes get blocked, excessive moisture can run off the ends of the trays in heavy, continuous, driving rain. 
With a cavity wall, even if the pointing is in poor condtion, moisture shouldn't reach the inner skin. Moisture will always penetrate the outer skin if there's enough heavy, driving rain.The
A test could be done with a hose on the area to see if it's getting in from the walls. 

csgohan4

stuart45 said:

A lot depends on what was used, how it was installed, were stop ends put on, weep holes put in etc. Unfortunately quality control in the building trade is much lower than a factory. Over the years, if the weep holes get blocked, excessive moisture can run off the ends of the trays in heavy, continuous, driving rain. 
With a cavity wall, even if the pointing is in poor condtion, moisture shouldn't reach the inner skin. Moisture will always penetrate the outer skin if there's enough heavy, driving rain.The
A test could be done with a hose on the area to see if it's getting in from the walls. 

yes, that didn't occur to me to use a hose to test this, Doh.

But I know it isn't the roof, but if it was cavity tray, weird that the pointing would have stopped it, albeit temporary 

One last question is which type of tradesman to look at the cavity tray?

stuart45

If you do a water test,  you need to keep it on for a while.
The reason the repointing helped was that it slowed down the moisture penetration enough for a while. Most of the moisture gets in from the perp joints. After a while they shrink slightly to allow enough of a gap for moisture to get in. Even sealing the brickwork doesn't stop this. When you think of the gallons of water hitting the wall, it only takes half a cupfull to get through and cause an issue. In the past, it was the arches that caused the most problems for designers to get the damp proofing details right. 
As the brickwork needs opening up, I'd get a good bricklayer in.

csgohan4

stuart45 said:

If you do a water test,  you need to keep it on for a while.
The reason the repointing helped was that it slowed down the moisture penetration enough for a while. Most of the moisture gets in from the perp joints. After a while they shrink slightly to allow enough of a gap for moisture to get in. Even sealing the brickwork doesn't stop this. When you think of the gallons of water hitting the wall, it only takes half a cupfull to get through and cause an issue. In the past, it was the arches that caused the most problems for designers to get the damp proofing details right. 
As the brickwork needs opening up, I'd get a good bricklayer in.

Much appreciated Sir, thank you  and everyone else that has contributed. This has been a bane of my life and worries. in some way i wished it was a roof problem, quick and simple to sort out. 

I've often thought about removing these arches and have a standard arched roof, so troublesome these vanity items. But no doubt will cost 5 figures to get a cranes etc to remove etc

stuart45

I forgot to mention how a borescope could be useful to look inside the cavity, especially when it's leaking.
When I talked about the arches, I meant the one over your window. The details for cavity trays were more difficult until they started making purpose built ones.

twopenny

If you enlarge that first photo you can see lots of gaps in mortar and some small ones in the seal all in that area.

I'm concerned how you're getting these photos, please take care. But they are good ones.

Maybe get as many photos of that gable and check by enlarging on your computer.
Might as well get a man with a ladder or whatever and get it all done at once. It's the set up that costs the money, not so much the volume.
Then you can rest at night 

Clever idea that tape. I'll use that if the need arises.

csgohan4

twopenny said:

If you enlarge that first photo you can see lots of gaps in mortar and some small ones in the seal all in that area.

I'm concerned how you're getting these photos, please take care. But they are good ones.

Maybe get as many photos of that gable and check by enlarging on your computer.
Might as well get a man with a ladder or whatever and get it all done at once. It's the set up that costs the money, not so much the volume.
Then you can rest at night 

Clever idea that tape. I'll use that if the need arises.

Yeah the photos were by my repointer before and some after repointing. But it sounds logical to be the cavity tray. 

twopenny

Ok. Did he do the seal also?

csgohan4

twopenny said:

Ok. Did he do the seal also?

yeah, repointed and water sealed coated