Foundation Depths
Discussion
I'm in the middle of a refurb of our cottage and want a small corner infill extension on the back for a utility room and en-suite above. It measures 3m by 2.5m and is two storey.
The Building Control officer has told me I need foundations of 2.5m depth due to being in clay and there being an Oak 10m away.
This seems very deep to me. Does anyone have access to the NHBC calculator/tables for foundations adjacent trees so I can check this. What would the corresponding width of the foundation be required?
Also what would the depth be for a single storey extension or conservatory I'm thinking about at the front of the property?
Thanks in advance
Paul
The Building Control officer has told me I need foundations of 2.5m depth due to being in clay and there being an Oak 10m away.
This seems very deep to me. Does anyone have access to the NHBC calculator/tables for foundations adjacent trees so I can check this. What would the corresponding width of the foundation be required?
Also what would the depth be for a single storey extension or conservatory I'm thinking about at the front of the property?
Thanks in advance
Paul
An oak is a high water demand tree and in the absence of a site investigation will assume the clay is of high volume change ie lots of potential to shrink and heave. Also if the oak tree is to remain the bco will take the full mature height in his calculation.
It does seem about right based on the above assumptions
It does seem about right based on the above assumptions
that has got to be the most idiotic reply I have ever seen, the BCO will have to see the complete excavation before concrete , so a pointless excersize. As a Building Contol Inspector I would need to see the entire excavation, if you disagree get in toyuch with an engineer, but he will still use the same calculator for the foundation depth, if you do dig a hole and fill with sand, you would only be harming yourself
Morgoth said:
that has got to be the most idiotic reply I have ever seen, the BCO will have to see the complete excavation before concrete , so a pointless excersize. As a Building Contol Inspector I would need to see the entire excavation, if you disagree get in toyuch with an engineer, but he will still use the same calculator for the foundation depth, if you do dig a hole and fill with sand, you would only be harming yourself
Typical BCO...no sense of humor. I should hope the OP has poured his foundations by now.
Even doing it all DIY at weekends and not having done anything since November due to weather the roof is going on this weekend!
Progress at Christmas time:
Foundations went down to 1.2m in the end by 600 wide. The trees in the vacinity were removed in the end. The local BCO has been extremely helpful during the whole build.
Progress at Christmas time:
Foundations went down to 1.2m in the end by 600 wide. The trees in the vacinity were removed in the end. The local BCO has been extremely helpful during the whole build.
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