When you can get your hand in it, like this one
<<insert photo >> can I do this?
Now I’ll confess that I have fairly small hands so maybe that’s not the best indicator but we do have the recommendations laid down by The Royal Institute of Chartered Surveyors in their document Assessment of Damage in Low Rise Buildings (BRE Digest 251) which classifies cracks.
These are as follows:-
0 – Hairline (less than 0.1mm)
Crack classification 1-3 are regarded as aesthetic whereas 4-5 are regarded as serviceability
Cracks 4-5 require the input of a Structural Engineer
Former boss would ask could he get his hand in it and if the person said no he wouldn’t tend to visit site. I understand that but always add the caveat that any crack that is classified as a 5 at some stage would have been a 4, and before that a 3 etc so it makes sense to gain an idea why something is moving and address it sooner rather than later.
Trust that you found this article of use but if you are in the Market Harborough area and require further clarification then please do not hesitate to contact me.