5837 soil assessments?

[sloth]

Does anyone have any views on what level of detail the soil assessment mentioned in section 4.3 needs to go to?

It says undertaken by a competent person to inform

rpa

tree protection

planting design

foundation design to take account of retained, removed and new trees.

Does this mean the rpa can be adjusted for some soils? Shouldn't it be the designers duty to check soil for suitable foundation design? What if there is to be no new planting? Should samples be taken across the whole site, or just an average area of soil?

Is it even necessary to include it in a single residential extension planning application?

Sorry for so many '?'s, contents of your picked brains to follow hopefully!........

[Ian Haynes]

Evening Sloth,

 

One thing to remember is that the standard is not exclusive used by arbs, it has been targeted at a range of different professions.

 

My view, is that the standard doesn't suggest that arbs will be

contacted about to make comments on soil investigations for foundation design but, would and should be expected to have a basic understanding.

 

The type of soil will have knock on effect on the type of new planting etc...

 

Hopes this helps,

 

Ian

[Jesse]

I assume you mean the new 5837:2012. I have not received mine yet but I assume that they refer to a simple tactile test to assess soil structure, a drainage assessment and a ph assessment ie what trees and plant species are present and doing well or a simple ph test could be carried out but I would not expect that detailed level of assessment at this point. Existing compaction could also be commented on and also the location/presence of virgin ground whioch would provide new quality planting areas subject to adequate protection measures being put in place during the construction phase of the development - my thoughts I hope it helps and I look forward to receiving my new 5837. This info would be invaluable data in respect of recommendations regarding future planting areas and species selection for those areas.

[Paul Jenks]

I'm looking at mine now and it's one of the bits that is fairly vague and open to interpretation.

As with the differences in the level of detail required between this and the last one in 2005 I dare say that as this is a new section, in the next evolution there will be much more guidance on this point.

Looks like something else that requires either training or subbing out. If the level of competency can be gleaned from your local TO or planning dept you may be in with a shout having read a book or two and armed with a piece of litmus paper.

[Jesse]

Evening Sloth,

 

One thing to remember is that the standard is not exclusive used by arbs, it has been targeted at a range of different professions.

 

My view, is that the standard doesn't suggest that arbs will be

contacted about to make comments on soil investigations for foundation design but, would and should be expected to have a basic understanding.

 

The type of soil will have knock on effect on the type of new planting etc...

 

Hopes this helps,

 

Ian

It is a nice touch though, if you have the knowledge, qualifications and can quantify your input - ie pile and beam foundation in respect of construction work within or around the RPA of a tree, general piling recommendations regarding type ie micro - plastic sheathed and including foundation depth. Most of this has relevance to clay soils, strip foundation precautionary measures advice. Developers are often cost driven sometimes alternative solutions are sought. PI, index levels, water demand of a given species all should ideally be included or commented upon, just my opinion. It often eveolves into a much larger project which could address in detail some issues which LPAs building control officers can often oversee and especially sub contracted ones. Clients are always very grateful of detailed information regarding their investment. NHBC chapter 4.2 good source of reference and my own personal favourite especially with all the spiral of new development across the country. British Geological Survey sheets, soil and drift editions - they will provide LPAs with a much deeper level of detail which might have ordinarily been overlooked unless of course it was covered within a geological survey but this may not have always been carried out. This can also provide details which can halt development in its tracks.

[Tree Man Tom]

It is a nice touch though, if you have the knowledge, qualifications and can quantify your input - ie pile and beam foundation in respect of construction work within or around the RPA of a tree, general piling recommendations regarding type ie micro - plastic sheathed and including foundation depth. Most of this has relevance to clay soils, strip foundation precautionary measures advice. Developers are often cost driven sometimes alternative solutions are sought. PI, index levels, water demand of a given species all should ideally be included or commented upon, just my opinion. It often eveolves into a much larger project which could address in detail some issues which LPAs building control officers can often oversee and especially sub contracted ones. Clients are always very grateful of detailed information regarding their investment. NHBC chapter 4.2 good source of reference and my own personal favourite especially with all the spiral of new development across the country. British Geological Survey sheets, soil and drift editions - they will provide LPAs with a much deeper level of detail which might have ordinarily been overlooked unless of course it was covered within a geological survey but this may not have always been carried out. This can also provide details which can halt development in its tracks.

 

How long did it take you to type that?

 

Sorry cant stay, off to bed with the lesbanian

[Jesse]

How long did it take you to type that?

 

Sorry cant stay, off to bed with the lesbanian

 

I'l get you, you wait and see, no mates in the pub tonght? :lol:

[Jesse]

How long did it take you to type that?

 

Sorry cant stay, off to bed with the lesbanian

 

I'l be round in five, get me a cold one out:lol:

[sloth]

Cheers all, some good views

[oslac]

I don't think many arb folk would have the skills or equipment to carry out a proper soil analysis. Normally on development sites, where soils are assessed, the structural engineer will make recommendations as to construction issues. I can't believe that a developer will take the word of an untrained arby when deciding what type of foundations to use. How many arby's can take soil cores down to 4m or more and then correctly analyse the soils within the core.

 

Even something which sounds simple like a pH soil test is full of potential problems. Many different pH kits give different readings for the same lump of soil. pH should be obtained from a sample base taken from a particular depth and in a particular pattern across the site.

 

My view is to tell the developer to get his own soil analysis carried out and then send you the results to include within your report.