Trenchfill or Not, is not a binary decision.

[Big Neil]

On 22/08/2018 at 18:30, Temp said:

Concrete. See.. .

http://www.nhbc.co.uk/Builders/Technicaladviceandsupport/TechnicalGuidance/61/filedownload,37205,en.pdf

 

Smashing - taaaaa.

 

On the subject of re bar someone mentioned above. Is there any real harm - cost aside - from 'throwing' some cage in during the pour as a sort of insurance, that is to say, would it do any particular harm?

[PeterW]

Yep as you should specify RC grade concrete not C grade to start with. Reinforcing also has to be completely  encased in concrete otherwise you can get    corrosion and concrete spalling that has significant structural impact. 

 

So unless it’s needed, don’t bother ..!!

[Simplysimon]

On 22/08/2018 at 15:42, Big Neil said:

 I understand principally the different Materials used here, but what is the infill from poured concrete to ground level ?

normally type 1, up here at least

[Tyke2]

Sorry if I missed something, but have you had bearing capacity and shrinkability testing done on the soil?

If not then the advice from either of the "experts" is pretty arbitrary. If it is of god bearing capacity and low shrinkability you could have a 150mm thick strip footing with 450mmm cover to ground level. This would increase thicker/deeper/wider as the soil bearing capacity decreases/shrinkability increases.

Proper testing and design by a qualified engineer could save thousands.