Hawthorn - affect foundation depth

[Giant90]

Hello All,

I have started to build my outbuilding/workshop as of last week. Cleared and plotted the ground out then called the BCO. There is a hawthorn 1.5m away from the foundation of the building so had to dig 2.5m down which I found takes a certain knack to dig.

As I am coming away from the hawthorn can I step the foundations higher to save on cost of spoil and concrete? I have looked at the calculator which according goes to 1m deep at 6m away from the hawthorn.

I have asked BCO and awaiting to hear back but some advice would be greatly appreciated.

Giant90

 

[Notch7]

Hello All,

I have started to build my outbuilding/workshop as of last week. Cleared and plotted the ground out then called the BCO. There is a hawthorn 1.5m away from the foundation of the building so had to dig 2.5m down which I found takes a certain knack to dig.

As I am coming away from the hawthorn can I step the foundations higher to save on cost of spoil and concrete? I have looked at the calculator which according goes to 1m deep at 6m away from the hawthorn.

I have asked BCO and awaiting to hear back but some advice would be greatly appreciated.

Giant90

I bet you wished you had dug out the hawthorn first!

Hawrhorn is known problem in zone of influence.

I hope you are digging with a digger and not going down the hole -its very very dangerous.

Yes it is possible to step upwards, although I cant remember the rules offhand.

To avoid stress, steps must be vertical and cleanly cut -not easy that deep, nor is scraping up the crumb.

 

[Giant90]

Hi Notch,

Thanks for the reply.

I have taken out the hawthorn now and wish I done it sooner! Lesson learned

I am using a 2.5t digger for the first time to dig the foundation and the digging isn't very clean so far plus digging 2.5m down is a struggle.

I have looked online for rules on step foundation away from a tree but no luck.

I was hoping to dig in 0.5m increments away from the tree so at 1.5m away - 2.5m deep, 2m - 2.33m, 2.5m - 2.16m, 3m - 1.99m etc to 1m depth.

Would this be ok?

 

[Notch7]

It says: d) Foundations stepped on elevation should overlap by twice the height of thestep, by the thickness of the foundation, or 300mm whichever is the greater. For trench fill foundations the overlap should be twice the height of the step or 1m whichever is greater

https://www.labc.co.uk/news/when-an...-on-a-sloping-site?language_content_entity=en

 

[Giant90]

Thanks again Notch. With the Hawthorn at 1.5m away makes it very tricky to plan stepped trenchfill foundation.