Cracks to plaster under roof joist on a party wall

[tiredoutnow]

Hi, so I am just confused over this 1970s ex council house I am buying, it has an offset party wall with the roof joining up at the back for a third of its width. I can see from the street that the neighbours ridge tiles have been heavily rebedded to about 7/8cm to keep them straight, and the pointing under the tiles is blowing out along the gable ridge, so I assume there ridge has dropped from the joists no longer holding on to the trusses.
So my worry is I have about 5 visable(only room without textured paper.historic looking) hairline cracks in a bedroom partywall,(room to the left with the paneling) starting at cieling level, runing into a crazy paving style hairlines and then there is a horizontal crack coming from that wall round to the back side short span wall.
So is the partywall bowing,
or is the party roof excerting a down ward/lateral force that is showing where the roof joist pushes on the plaster wall beneath, it doesnt look frightening but I dont want a party wall dispute or a problem I cant fix.
Thanks.

 

[tiredoutnow]

It is a cavity build external wall but I dont know if the internal party wall is a cavity?

 

[^woody^]

Looks like old cracked plaster for no reason other than being old.

 

[tiredoutnow]

Hi woody , sorry for the bad pictures, so it does not look like thrust from next doors wall and roof . Could it not be that the middle brick skin off the party wall has shoved across the 3cm cavity and is pusing on the inner breeze block plastered wall? so in the roof (i did not look) could the single skin brick be collapsing across.

 

[Leofric]

Interesting waste pipe arrangement , very artistic !- is that an svp or a rainwater pipe next to it ?
Maybe you need a structural survey report if you think it is more than just cracked old plaster.

 

[^woody^]

so it does not look like thrust from next doors

No. Walls don't tend to move sideways, especially party walls.

You have used a few key words in your posts, which I would not expect anyone to use unless they already know what they meant. Not meaning to be rude but are you reading too much about symptoms or are you experienced with building defects?

 

[tiredoutnow]

I am reading alot , I have been a floor tiler and building clenner using acid or sandblasting. I do a lot of diy, so no I am definatley not a a bricklayer or structural engineer , I was just looking for advice so I dont have to fork out £425 for a structural engineer to look for an hour tommorow, it will take me 50 hours work at 8/hour to pay him back for his opinon. So any help is apreciated as i am a skint first time buyer on a budget, boohoo for me.

 

[^woody^]

Ok that’s fine. It’s just that the more you read about defects the more you start to start to think that your house has these problems.

The way these things are determined is by looking for typical signs in typical places. When walls move the type of cracks are indicative of specific movement and specific causes. What this means is that apart from the really obvious causes, cracking is listed in terms of the most and least likely causes. So crazed cracking in plaster and a few random long cracks are more likely to be from old plaster, dried and blown from the wall than they are from wall movement. Ceiling cracks are commonly shrinkage from heat and moisture in the room. Any movement of that wall would normally produce different cracks, and taken with the fact that the wall is most unlikely to move in the first place, then movement is discounted as a probable cause. That’s not to say that movement is not possible, as it is, but unless there are other factors to support movement, then it can be deemed unlikely.

The only way to be 100% sure is to have it looked at professionally on site. But from pictures only its unlikely to be any of those things your mentioned and seems to be typical and common plaster cracking.

 

[tiredoutnow]

Hi Woody , thanks for that. I went back today and had a better look at the roof from the ground. As I was looking for specific causes, the roof has not travelled laterally more than a few inches, and the sagging does not look that severe , coupled with as you say the cracking pattern would be different(what would the cracking be like?)
I think I am just over worrying, If I go through with it I will still pay for a survey as I still am unsure about the damp internal breeze blocks(i am hoping that is from a flood 2 years ago). Just whilst im here , if it did have damp could I repoint the breeze blocks with lime and lime plaster to let them breathe, I know its best to find where the damp is from, but if it could not be stopped would lime+breatable paint be good enough for it not to show up as damp, admitidley it does not smell or seem damp on the surface just an inch in, I noticed next door but 1 had just had a liquid dpc drilled in , which isnt a good sign in a 1973 house with a dpc dpm slab build. Thanks for your time.

 

[^woody^]

could I repoint the breeze blocks with lime and lime plaster to let them breathe

Reading to much again. The only lime in that house would be if the previous owners had a few cocktails on the patio.

No, you should not do that.

Your OP did not refer to any damp

 

[tiredoutnow]

No damp was not my OP but I started a damp post with no response. I know it would not of ever had lime in it at that age, I just thought it was more breathable than mortar and plaster, so if I did have a few failed areas I could try to let them breath as opposed to digging up the screed or tanking or ???

 

[^woody^]

I could try to let them breath as opposed to digging up the screed or tanking or ???

No, the wall/floor or whatever will just stay damp.