crack in pebble dash

[Jago2k]

Hi
We have recently brought a new house, all the house is in a good state of repair with a new recent new roof, kitchen, bathroom etc.
The pebbledash has not been touched. When we had bad weather last week I noticed a damp patch at the top of the wall upstairs on the wallpaper. Checked outside and there was a crack in the pebbledash that looks like it's tried to be repaired mastik (prob spelt that wrong)
The damp follows the line of the crack. had the roof checked and that I've been told looks fine.
Could that crack cause the damp patch and what should be done to repair it.
so what's a ballpark on how much it is to be repaired

 

[JohnD]

how old is it? Can you scratch it to crumbs with your thumbnail?

 

[Jago2k]

Not sure how old but it's been there for the life of the building. We think it was built in 1960ish. This is a pure guesstimate. It doesn't crumble but the stones fall off

 

[theprinceofdarkness]

The crack, how wide is it? Normally what happens is that when new the building "settles" i.e. it moves about a bit. Old old properties the mortar is soft so the bricks just move in the mortar. With modern cement mortar made houses the mortar is as hard as the bricks , so movement can cause cracks to run through the brickwork. It sounds as this is your problem. The pebbledash is still stuck hard to brickwork which has cracked all the way through. In the inside the crack can be hid with a bit of filler and white paint.
The way I would proceed, first I would check all external features, blocked gutters, poor down pipe joints etc. This is to make certain that there is no extra water being directed to the wall. Then I would tap around the crack with the butt of a hammer, to see if any of it was loose. This can cause water to become trapped and all come out at the first hole in the bricks. if it appears to be truly fixed then tarting up the filler if there is something obviously wrong with it. If the filler appears to be intact, then the problem remains, how does water get through the pebble dash, and why only at one place?
As you know water runs downwards, so the bottom end of the crack, is it higher or lower then your damp patch. I would tend to suspect the very top of the pebbledash under the eaves, behind the soffit board (if fitted) or some other detail. The filler will hold rain back if its done properly and the pebble dash in its self water proof, or you would have damp everywhere.
Frank

 

[JohnD]

if it has a crack, it is probably wicking the water inside. Loose old pebbledash often has loose scabs with gaps behind that fill up with water. It would be best to hack it off and re-do.

However the shape of the crack may indicate cracking brickwork, so post some photos, inside and out.

Look at the gutter and downpipe during rain as water may be spilling onto the wall.

 

[Jago2k]

It's had a new roof and gutters, but suspect that the old roof was quite bad going by old Google street view images so damage could have been done by that. There are no cracks inside that I can see although is wallpapered, couple of places the plaster sounds a bit hollow when knocked. I will upload some pics tomorrow when lighter.
Is this a big job, if I were to pay someone what would be a fair price.
One of the roofers I got to look at it suggested he could take of old lasting and brush a ova cement mix in, would this work?