I'm planning to build an outbuilding roughly 3m x 4m and within my PD rights and outside building regulations.
The building itself is to be about 11 courses of brick high (single), timber framed, clad in wide boards to a 2.2m eaves height then pitched roof to 3m. Slab is to be 150mm hardcore, blinded, DPM then 100mm concrete with mesh.
I'm on medium density clay soil BUT I'm building within the canopy of a huge sycamore (less that 1m away) and 1m to a hawthorn hedge.
I know what building regs state and the NHBC state for soils conditions and tree roots but as neither are covering liability then I don't need to worry like they make us all do!
I planned, initially to dig down to 425mm (shock horror!), with 200mm concrete with 10mm rebar doubled up, then 225mm concrete block to bring me up to ground level. I was going to raise the slab by 75mm from the ground level but still make it 100mm thick.
I have to keep in mind that it's only a glorified shed, not the forth road bridge so I don't want to go mental with the depths so it can stand for 100 years, just enough not to cause me too much grief in the next 10 or so.
The question is what to do for the foundations and the tree roots that are running through it?
Some roots are 3-4" thick so should I be cutting through them this close to the tree? They're also running from ground level down through the trench.
Could I dig some pads along the trench then stick 200mm of concrete over the roots (instead of the block), like a ring beam, but just on the one trench?
Would I be better building a raft and if so, I'd still be within the area for roots so would this make a difference?
The building itself is to be about 11 courses of brick high (single), timber framed, clad in wide boards to a 2.2m eaves height then pitched roof to 3m. Slab is to be 150mm hardcore, blinded, DPM then 100mm concrete with mesh.
I'm on medium density clay soil BUT I'm building within the canopy of a huge sycamore (less that 1m away) and 1m to a hawthorn hedge.
I know what building regs state and the NHBC state for soils conditions and tree roots but as neither are covering liability then I don't need to worry like they make us all do!
I planned, initially to dig down to 425mm (shock horror!), with 200mm concrete with 10mm rebar doubled up, then 225mm concrete block to bring me up to ground level. I was going to raise the slab by 75mm from the ground level but still make it 100mm thick.
I have to keep in mind that it's only a glorified shed, not the forth road bridge so I don't want to go mental with the depths so it can stand for 100 years, just enough not to cause me too much grief in the next 10 or so.
The question is what to do for the foundations and the tree roots that are running through it?
Some roots are 3-4" thick so should I be cutting through them this close to the tree? They're also running from ground level down through the trench.
Could I dig some pads along the trench then stick 200mm of concrete over the roots (instead of the block), like a ring beam, but just on the one trench?
Would I be better building a raft and if so, I'd still be within the area for roots so would this make a difference?
