Root protection zone

[flanagaj]

I am somewhat confused regarding what has been proposed for the tree that is to remain on site.  The diagram is below and the shaded purple area is where there used to be a concrete slab.  I used an excavator last November to break all of that up.  The tree survived and is in full bloom.   The RPA has been calculated as 4.68 metres (see dotted circle on below diagram).  But the Arboriculturalist has then stated the following

CONSTRUCTION
13.7. All barrier fence and ground protection is to remain serviceable and in position for the duration of the development. No adjustments are to be made unless with the written agreement of the planning/arboricultural officer.
13.8. Temporary ground protection to be installed following removal of the building over the root area of tree 5
13.9. The project arboriculturalist will be on hand to provide arboricultural advice if it is needed.

 

I assume that I only need to provide ground protection to the area within the 4.68m RPA zone?

The reason I ask, is that I need to install a waste pipe down the side to the new drainage field.

[JohnMo]

Yes

[nod]

You can only do your best 

No one checks these conditions Certainly not Building Control 

Ours where totally impractical All along our long drive We simply dug through the roots It was with that or have no drainage or workshop 

NO trees where harmed in this process All are still standing and full of leaves  😁

 

Our precious build had two trees with TPOs Which we were able to fenced off for the entire build 

Two years on the local water authority moved a hydrant from the base of one of the oaks and simply dug under with a five ton machine I rang planners thinking I’d could be blamed and all I got was Ah well Couldn’t be helped 

[flanagaj]

2 minutes ago, nod said:

I rang planners thinking I’d could be blamed and all I got was Ah well Couldn’t be helped 

😂

[JamesPa]

2 hours ago, flanagaj said:

I am somewhat confused regarding what has been proposed for the tree that is to remain on site.  The diagram is below and the shaded purple area is where there used to be a concrete slab.  I used an excavator last November to break all of that up.  The tree survived and is in full bloom.   The RPA has been calculated as 4.68 metres (see dotted circle on below diagram).  But the Arboriculturalist has then stated the following

CONSTRUCTION
13.7. All barrier fence and ground protection is to remain serviceable and in position for the duration of the development. No adjustments are to be made unless with the written agreement of the planning/arboricultural officer.
13.8. Temporary ground protection to be installed following removal of the building over the root area of tree 5
13.9. The project arboriculturalist will be on hand to provide arboricultural advice if it is needed.

 

I assume that I only need to provide ground protection to the area within the 4.68m RPA zone?

The reason I ask, is that I need to install a waste pipe down the side to the new drainage field.

Ive spoken with a couple of aborists about RPZs on several occasions.  The things to avoid (they tell me) are : 

 

• Compacting the soil over an extended area in the RPZ - because it means that the roots dont get moisture/cant grow (hence ground protection)
• Cutting tangential trenches through the RPZ - because you cut through lots of roots which, by and large, run radially.  Radial trenches are not so bad
• Unbalancing the tree by cutting through lots of roots on one side only (which is not to say you should balance it by cutting through lots of roots on the other side!)

Amending pipe runs if necessary to avoid these is good practice.

Its possible to excavate under roots if there is no way of avoiding the RPZ

 

Maybe that helps

Edited April 26 by JamesPa

[Mulberry View]

The whole RPA thing drives me crazy. We had to install a £10k Geocell driveway before we were permitted to commence, but the Garage demolition that formed part of the approved plans (and thus the commencement) stood in front of everything with no route past until it was demolished. We just got on with it, we had no choice.

 

We were told that we would have to hand-dig our multi-service trench which sat in the outer 5% of the RPA of a pair of unprotected Scots Pines and we have a 70foot Hornbeam with a 10 metre radius RPA that has controlled the entire size and shape of the house we're building. We're not allowed to store any materials within that RPA and even a 1-tonne digger would need an engineered ground protection solution before being able to pass over it.

 

Meanwhile, Cadent have carved a trench 2 feet away from the trunk of an ancient (200 year old I'd guess) Oak tree beside a road near me and in a City Centre urban furniture project, they were diggering up to and around all the mature trees with a 5T machine, with only the trunks protected.