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Groundwork & Foundations

New Foundation- joint to existing or acceptable at different depth

Anonymous user 09/03/2024 - 3.11 PM

I have firm sandy soil which building control have advised that is typical for my area and a strip foundation at 900mm is typical. I've dug a little trail excavation to check an existing rear extension foundation depth. I was able to quickly get down to 1m but still can't find the existing foundation. I've hit something hard 1.2m, lets say this is the foundation (I didn't have time to dig further). would it be expected that the new foundations would have to be at the same depth or slightly lowed than the existing or could they be higher. The ground is so firm at 900 not sure why it's so deep.

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4 Answers

Regency conservatory roofs ltd

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Thornton Cleveleys
Building inspectors normally like the new footing to be at the same depth as the existing house footing
Answered21 June 2020
1

SIMON CURRY-TAYLOR BUILDING SERVICES LTD

Rating: 5 out of 5
Ilkeston
it would suggest to me that your existing extension foundation was dug to the depth of your original building foundation. Years ago that used to be rule of the thumb so to speak. As to weather they would make you go that deep now would be down to ground conditions and the opinion of the building inspector. Invite him/her for a site visit and ask him/her up front what they would prefer. The last thing you want is to upset them from the start.
Answered22 June 2020
0

Anonymous user

You go with what your structural engineer tells you to do and they will clear it with the local building control before works start.
Answered30 June 2020
0

proslab

Rating: 5 out of 5
Highbridge
Best if you can dig down to find virgin ground,then get architects to agree this will be suitable for foundation depending on what you’re building on ,ie single or double storey building pay now or can cost you a lot more money later on regards jason
Answered11 July 2020
0