I saw a house recently, approx. 20-30 years old in the London area. I cannot say if it has double tied cavity walls or it is the cheaper version which is essentially a wooden house with a single brick wall surrounding it.

There were many thin cracks in the bricks, easily 40 per wall. Nearby houses made of a different type of brick didn't appear to have many.

Would this be a problem or would that normally only be a case for potential worry if there are continuous cracks including the mortar?

  • Could you provide a photo the placement of the cracks could be an indication of foundation problems. But right now we can only guess. Remember the mortar could have been repointed o you don’t see a crack there. Without a photo we can not help.
    – Ed Beal
    Oct 31, 2019 at 15:08

2 Answers 2


Cracks are a sign of movement. Movement from 1) a settling foundation, 2) shifting soil, 3) structural wall movement.

1) Obviously, if the foundation is setting the wall will settle. I’d look around the perimeter at the concrete stem walls to see if there are any cracks in the concrete.

You should look around the perimeter from inside the crawl space too.

2) I’d check to see if soil is sliding away from the house due to erosion or neighbors installing underground pipes, patio footings, etc.

3) If the wall is the single wythe brick type (we call them brick veneer walls here in the U.S.) the wood could be shrinking due to drying, dryrot, etc. To check this, simply check to see what is opposite the cracks on the interior walls.

BTW, we don’t design brick walls with “strong” mortar. The mortar mix is always chosen to be weaker than the brick in compression and tension. That way, when the house moves, (and all houses move,) the cracks will develop in the mortar, which is easier and cheaper to fix than a bunch of broken bricks.

There is a possibility that the builder was able “to get a good deal” on brick seconds. That is to say, the bricks could have been rejected and sold cheaper. There are tests to help determine the quality of the bricks. Here’s a website to help you get started:



It depends.

I presume this is in the context of "I am thinking about buying this house"? If so, you need to ask a building surveyor to carry out a survey, paying particular attention to this cracking. This will give you an answer of "run away", "you need to spend £x,000", or "don't worry about it". In the middle case, you can use the survey results to negotiate with the vendor ("x" may be larger than 9).

  • In the UK, sellers have to provide a surveyors report...
    – Solar Mike
    Oct 31, 2019 at 9:58
  • 1
    Correct, considering buying it. @Solar Mike - When I have done this previously, the survey was up to the buyer.
    – nsandersen
    Oct 31, 2019 at 10:12
  • 3
    @SolarMike I have sold five houses in England, the most recently in 2015. The only report I have ever had to provide was an Energy Performance Certificate. The building survey has always been the responsibility of the purchaser. Oct 31, 2019 at 10:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.