When is a crack in a wall

something to worry about? We bought our house 14 years ago and installed CH, there were a few cracks in the plaster on ceilings etc. that have become a little bit worse most of which look benign enough but one in the upstairs exterior wall that is causing me to think twice about it. You can see it starting in the back corner of the house, the tiles in the bathroom have spread apart by 5mm or so, continues into the toilet, same story, and then onto the half-landing where it’s maybe 10mm wide at most but also seems to be not flush i.e. you couldn’t put a straight edge against both sides of the crack, it’s a few mm out of plane. It’s an exterior facing wall but when I’ve hung out of the bathroom window I can’t see any cracks on the actual exterior wall.
So, does this sound like something I need to get checked, and if so by whom – structural surveyor? Will my insurance be likely to cover any remedial work?

I was told as a rule of thumb(sic) that its only a concern if you can get your hand into the crack

I was told as a rule of thumb(sic) that its only a concern if you can get your hand into the crack

It’s little nuggets of wisdom like this that make a good nurse. 😉

Thanks TJ, it’s not there yet but a stitch in time etc etc would it be better to get it looked at now?

Sounds like it needs attention.

If it’s going straight down, ie bricks are cracked rather than stepped and following the mortar, it’s worse.

If i could get a £1 coin in the gap i would worry.

Get a decent measuring tape and start measuring the nearest walls every month, once you can demonstrate a pattern i would look for a cause, any building works locally etc.

If you find something then on to the insurers to get it sorted for you.

How old’s the house?
Has there been any building development or drainage done nearby recently?

The usual way to determine if things are getting worse is to superglue a strip of glass (size of a microscope slide) across the crack and come back a while later to see if it has cracked.

http://surveyequipment.com/tell-tale-crack-monitoring-gauge/?source=googleshopping&locale=en_GB&country=GB&gclid=Cj0KEQjw-73GBRCC7KODl9zToJMBEiQAj1Jgf54IewFVleTwOOOS-gbP8CoKSZaFEQIZL0ABEf4_adEaAv6w8P8HAQ

or one of these if you want to be technical.

Damn you jambo!

House is about 60 years old on this side. The crack runs along the wall, not in a straight line but it’s difficult to tell as most of where it’s cracked is tiled. No building works etc.
Might take some photos with a ruler for scale and monitor it for 6 months or so.

What is the construction of the house? Is it cavity wall, is the inner wall, brick or concrete block? End of terrace, semi-detached??

Why do you have to hang out of the bathroom window to look at the outside wall, can’t you see it from the ground??

Do you have a lot of stuff stored in the attic? Anything changed with regard to the roof (new tiles etc)?

It’s not a crack… it’s a sticker… igmc

What is the construction of the house?

Brick, semi-detached house

Is it cavity wall

yep, we had those polystyrene balls squirted in there 2 years ago. The crack was there before then though, don’t think that has affected anything.

Why do you have to hang out of the bathroom window to look at the outside wall, can’t you see it from the ground??

because I was in the bathroom when I was discussing it with my missus and uhmming and ahhing about it again. And who doesn’t like to hang out of a first story window now and again.

Do you have a lot of stuff stored in the attic

Well everyones perception of “a lot” is different but I’d go with yes, loads of stuff that the kids have grown out of that the missus doesn’t want to throw out.

file:///C:/Users/User/Downloads/BRE_Digest_251_Assessment_of_damage_in_low-rise_buildings.pdf

BRE_Digest_251_Assessment_of_damage_in_low-rise_buildings.pdf

Thanks for that, I downloaded a copy and it seems like a very useful guide and going by the classifications my crack is superficial but I will monitor it just in case.
Cheers again.

Suggest that you have a good look from the outside. I would have thought that the inner and outer walls would move together if it is some form of settlement.

If it is just the inner wall that is cracked it could be corrosion of the wall ties.

Extra load on the load bearing inner wall could lead to movement and cracking (e.g. loads on the roof timbers) or possibly a load bearing wall that wasn’t removed properly.

I couldn’t get squirrels link to work, but try googling: Assessment of damage in low-rise buildings.

I would get a local structural engineer to come over and give you a report. I wouldn’t have thought it would be too much in the way of a fee for that sort of report and would give you pace of mind rather than worrying about it. They may install crack monitors to see if its active of not. You should check the details of your house insurance too, as you mention, just to check if there is a procedure for notification.

I would get a local structural engineer to come over and give you a report. I wouldn’t have thought it would be too much in the way of a fee

Good luck with that.

The bit above about the mortar cracking and not the bricks is rubbish btw. It’s just an indication of which is the stronger material.
10mm is a size where I would be monitoring to be fair especially as it’s in various rooms.
As a rule if it’s deemed as any kind of subsidence there’s usually a good old excess (2k on mine) to pay on your policy but you will be covered for the rest.

Any large trees nearby? by ‘large’ and ‘near’ the rule of thumb is taller than the distance away, however it varies with species. Oak is fairly bad for example, they suck a lot of water. Large trees are a possible cause of subsidence, particularly on clay soils (no idea what you are built on). If its vegetation causing shrinkage of the soil it will be seasonal, closing a bit each winter and opeing a bit each summer. The bit about glass strips across cracks was the old way, these days they glue little markers either side of a crack and use digital calipers to measure the movement down to 100th of mm every couple of months.

If you contact your insurer they will probably ask a few questions abut size, does it taper in width, and so on and if they think there is any chance of subsidence they will send an engineer to assess it. Engineer will then get the monitoring set up if they think there maybe some subsidence.