Heave

[treequip]

No we shouldn't Treequip, but the NHBC were fairly well informed when setting out their criteria.

 

I think Jesses first post nailed it.

 

If a big tree is near a house on clay soil you need pro help.

 

A little tree further away on more friable soil you need no help.

 

It's the bits in between that make Arbtalk.

 

We're they though?

 

The first thing they produced was based on the data from the Kew root survey, Cutler and Richardson went on record describing that rip data set as flawed aspen statistically limited but NHBC used it anyhow because it's all there was.

 

What are they using now? Has there been any peer reviewed research on root development and water uptake or are they still on the old data.

[Jesse]

What height does a tulip tree grow and what water demand does nhbc class it as?

 

Not every tree sp is in it Tulip is and classed as Low water demand and mature tree height 20m a lot is also down to knowledge that you build up over the years. Also known root development characteristics of a sp, NHBC Standards just provides a tool or bench mark to carry out the calculations, if in 4 years a house splits you will have to quantify how you arrived at your assessment of the risk associated with the tree. Climatic considerations also need to be taken into account.

[Mark Bolam]

We're they though?

 

The first thing they produced was based on the data from the Kew root survey, Cutler and Richardson went on record describing that rip data set as flawed aspen statistically limited but NHBC used it anyhow because it's all there was.

 

What are they using now? Has there been any peer reviewed research on root development and water uptake or are they still on the old data.

 

Agreed.

 

Note my cunning, politician like phrase 'fairly'.

 

If any real doubt exists, consultation with a structural engineer would be my advice.

[William]

a lot is also down to knowledge that you build up over the years...if in 4 years a house splits you will have to quantify how you arrived at your assessment

 

How can I quantify experience? A lot could change in 4 years - my low water demand tulip tree could reach 22m. Shouldn't nhbc calculate in expected water uptake based on size/leaf area rather than species?

[Jesse]

Agreed.

 

Note my cunning, politician like phrase 'fairly'.

 

If any real doubt exists, consultation with a structural engineer would be my advice.

 

There is that option but who understands the health and condition and its potential to develop of a tree better than a tree surgeon ? most structural engineers can only define broadleaved trees from conifers . And what about taking into account fungi ? the plot thickens .

[Mark Bolam]

Tree surgeons don't understand soil, engineers don't understand trees. That's the way it is. Insurance co's don't understand anything.

 

There is no formula.

 

You take down a 300 year old Oak beside a 700 year old farmhouse.

That water is going somewhere. It's going somewhere it did before that old Oak started sucking it up.

[treequip]

How can I quantify experience? A lot could change in 4 years - my low water demand tulip tree could reach 22m. Shouldn't nhbc calculate in expected water uptake based on size/leaf area rather than species?

 

Unless you are a house builder forget NHBC.

[Jesse]

Tree surgeons don't understand soil, engineers don't understand trees. That's the way it is. Insurance co's don't understand anything.

 

There is no formula.

 

You take down a 300 year old Oak beside a 700 year old farmhouse.

That water is going somewhere. It's going somewhere it did before that old Oak started sucking it up.

 

I understand Soil, I understand Trees, I understand Foundation designs. It is the insurance company's who require a second party to except liability for there invested interest in a property . It is the insurance company who request an Arboricultural Subsidence Risk Assessment. It is me who takes on that risk. I can't say any more than that really not without going into great detail and I don't really wont to do that or else I will be giving you all idea's. I have been doing them since 2006 . Good money.

[treequip]

I understand Soil, I understand Trees, I understand Foundation designs. It is the insurance company's who require a second party to except liability for there invested interest in a property . It is the insurance company who request an Arboricultural Subsidence Risk Assessment. It is me who takes on that risk. I can't say any more than that really not without going into great detail and I don't really wont to do that or else I will be giving you all idea's. I have been doing them since 2006 . Good money.

 

Just a tad patronising there?...

[Pedroski]

Just a tad patronising there?...

 

That's what I thought.... hope Jesse doesn't take advantage of stuff other people say for ideas!