root protecting foundation systems?

[stihllearning]

evening all,i recently removed a row of lleylandii for someone and after we had finished he told me he planned to build a workshop were they stood.

 

theres a tpo'd beech tree about 2 metres away from where he plans to put some of his footings and i told him it was unlikely to get consent becuase of the proximity of the roots.

 

it got me thinking that there must be a way of hand digging and building footings to allow for the developement of the roots.

 

so does any one no about footing systems that would allow this or test cases where consent has been granted in a similar situation.

 

awaiting response bill

[Giles Hill]

Small-bore piles are the normal way to go to avoid root damage. If the is solid an impermeable it needs to be elevated to allow gaseous exchange.

 

Here is a case study by Jeremy Barrell. I'm not sure how old this is, or if it has been improved upon: http://www.aie.org.uk/download/BuildingsNearTrees.pdf

 

Alternatively, a simple method might be to do a raised timber structure for the base - like you would construct decking.

[armchairarborist]

expose roots using hand digging methods or air spade, then bridge over the roots with blocks etc (like bridging services), and backfill with nice soil, don't leave roots exposed for long, just enough to map them and then re-cover, obviously check with local tree officer/planning dept first before work starts.

[janey]

Google "deck foundations".

[nepia]

I know nothing of it personally but I do know of an extension built on aforementioned piles (but steel ones) inserted to avoid the roots of a large TPOd Atlantic Cedar. Presumably temporary exposure of the roots was necessary to map them and hence avoid them with the piles.

Will be returning in a few weeks; want me to ask for more detail?

 

Jon

[Ruskins Trees]

Screw Piles are tiny. We Air Spaded holes in a back 'garden' in central ldn. The garden was a mature London Plane, not so much within the root zone as right up against the trunk!! We found gaps in the root system for the screw piles. The TO was delighted!

[stihllearning]

giles thank you, i think i'll pass that on to my customer

[stihllearning]

thanks to you all, jon i think i have what i need.

 

i'll keep you all posted,looks like i get to use an airspade ! yippee