Is there a construction industry performance standard that defines if
1/8" settling crack in 2 months (too soon, too much)is normal or
abnormal? I know concrete hairline shrinkage crack is normal but a
settling crack of such a width so soon is normal? I doubt it. I like
to have references if anyone knows.

Thanks.

"Peter Shepherd" wrote in message ...
A very rough rule of thumb is adding up all the cracks in the wall, and if
they're over 1/4" total, then you have significant settlement. Within this
rule the engineer has given a plausible description.

Vertical & diagonal are usually safer than horizontal cracks; the latter
could indicate a possible wall failure & collapse.

Did the builder perform soil testing on various points of the site,
especially if that neighbourhood is prone to unstable soil conditions.
What is the experience of other owners in that area?

Are the footings adequate for that soil?
Is there adequate rebar in both footings & foundation?

If so, how did the 1/8" crack happen so soon?
I've never heard of 1/8" differential settlement crack being an accepted
part of a "design". Whose design is he referring to? (Mangle-Wood
Construction?) Adequate perfomance on an older structure, yes, but I'd like
to see the passage in an engineering text that says it's normal for a new
foundation. While I haven't been around a lot of recently-constructed
foundations, it seems a little odd to me.

Was the foundation backfilled too soon, with heavy equipment mechanically
damaging the foundation before it cured?

Expansive soil can add typically 10% more pressure than non-expansive soil.
This may have buckled the footing & foundations slightly before they cured.
Is it very wet there, or did it rain much? A high water-table can increase
hydrostatic pressure also.


Good luck with it.


Peter Shepherd
63 Pauline Ave
Toronto