Crack between brick extension and house

[Mark R]

We’ve discovered a large crack in the join of brick extension to our house. We had already noticed some cracking along the mortar lines of the bricks near where the extension was toothed-in to the house but they are quite small and appear to have been there for some time. The large crack near the top we think is more recent and I’m worried we may be experiencing some subsidence. There are a lot of oak trees among others in the vicinity and after the past couple of hot summers we have, I think the trees are soaking up all the moisture in the surrounding sub-soil. Does this look serious?

 

[KenGMac]

Mark R, good evening.

A few questions please?
When was that re-pointing done? because it is cracking again.
How wide was the crack at the top of the wall?
is there a corresponding internal crack?
How old is the extension?
Do you know if your property is on shrinkable clay? if so do you know anything at all about the depth of the Foundations?

Finally, really sorry about this, I am not slagging you off but? that re-pointing work is doing nothing at all but drawing your eye to what may be a defect, even a novice conveyancing Surveyor will clock it?? when you come to sell.

ken.

 

[Notch7]

We’ve discovered a large crack in the join of brick extension to our house. We had already noticed some cracking along the mortar lines of the bricks near where the extension was toothed-in to the house but they are quite small and appear to have been there for some time. The large crack near the top we think is more recent and I’m worried we may be experiencing some subsidence. There are a lot of oak trees among others in the vicinity and after the past couple of hot summers we have, I think the trees are soaking up all the moisture in the surrounding sub-soil. Does this look serious?

Because it's been repaired it's not possible to know the size of the cracks.

On the face of it, it doesn't seem much to worry about.

The thing to remember is the house and extension are on two separate foundations, probably of different depths or construction. With ground movement they will act independently and toothed in brickwork is totally unforgiving.

If it was subsidence, I would've said the corners of the extension would be showing cracking

 

[^woody^]

The extension should never have been bonded as it will always move slightly. It should be joined with a flexible metal tie to accommodate any movement.

There is nothing in that picture to suggest any abnormal movement

 

[Mark R]

Mark R, good evening.

A few questions please?
When was that re-pointing done? because it is cracking again.
How wide was the crack at the top of the wall?
is there a corresponding internal crack?
How old is the extension?
Do you know if your property is on shrinkable clay? if so do you know anything at all about the depth of the Foundations?

Finally, really sorry about this, I am not slagging you off but? that re-pointing work is doing nothing at all but drawing your eye to what may be a defect, even a novice conveyancing Surveyor will clock it?? when you come to sell.

ken.

Hi Ken.
The repointing isn’t really repointing. When we had the survey done (we moved in three years ago), the surveyor highlighted the cracks but said they were small but to get the cracks filled to monitor movement. I did it with a very fine amount of mortar which was being used elsewhere (it’s temporary and we will get it done properly).A year later the fine cracks reappeared. The crack at the top, where the wall is rendered, is actually a chunk. I will take a closer photo of it tomorrow and post it here.
The extension was built a few months after the property was finished in 1977 and was completed by the developers (I have the planning applications). I suspect the first owner asked the developers to build one not longe before the house was finished. I’m not sure about shrinkable clay. I’d have to check the survey.

 

[Mark R]

Mark R, good evening.

A few questions please?
When was that re-pointing done? because it is cracking again.
How wide was the crack at the top of the wall?
is there a corresponding internal crack?
How old is the extension?
Do you know if your property is on shrinkable clay? if so do you know anything at all about the depth of the Foundations?

Finally, really sorry about this, I am not slagging you off but? that re-pointing work is doing nothing at all but drawing your eye to what may be a defect, even a novice conveyancing Surveyor will clock it?? when you come to sell.

ken.

Mark R, good evening.

A few questions please?
When was that re-pointing done? because it is cracking again.
How wide was the crack at the top of the wall?
is there a corresponding internal crack?
How old is the extension?
Do you know if your property is on shrinkable clay? if so do you know anything at all about the depth of the Foundations?

Finally, really sorry about this, I am not slagging you off but? that re-pointing work is doing nothing at all but drawing your eye to what may be a defect, even a novice conveyancing Surveyor will clock it?? when you come to sell.

ken.

There is some internal cracking, mainly by the corner of the sliding door but also along the top of the wall, near the ceiling.

 

[Mark R]

 

[Mark R]

 

[Mark R]

 

[Mark R]

 

[Mark R]

 

[Mark R]

 

[akist]

Academic question, would it have helped if the extension's foundations had been joined into the existing with steel dowels while they were being poured?

 

[noseall]

There is nothing in that picture to suggest

I will say that they have carried out an almost invisible repair. You can hardly tell!

 

[noseall]

Academic question, would it have helped if the extension's foundations had been joined into the existing with steel dowels while they were being poured?

BC often ask that the new foundations are allowed to travel under the existing (underpin), as when it is favourable.