eucalyptus tree and Foundations

[mishel02]

I have a eucalyptus tree 5.5 metres away (9m hight) from the far corner of my propsed single extension. The foundations were dug 900 the building inspector said no they have to be 1.8m in 2 metre directiosn from the corner

he has now come out and said he wants one whole side 1.8m I am so upset and fed up

Can anyone tell me if this is right

 

[freddiemercurystwin]

Do you have clay soil? If so it sounds about right, Eucalyptus trees are generally a vigorous species with an extensive rooting system and importantly have a high water demand. As clay is shrinkable when the tree draws up moisture the surrounding soil can dry out and shrink, causing subsidences in the earth surrounding foundations unless they are below a certain depth based upon the size of the tree at maturity. At least he hasn't asked for piles. This issue crops up on the forum every now and then so is not that uncommon. Hopefully someone with a bit more knowledge will be along to add to the thread.

 

[Tipper]

Eucalyptus trees grow very big and very fast. Deep foundations is a start but better to remove the tree......if it's yours to remove that is!

I was asking my neighbour to remove his for a couple of years before he finally accepted that is was getting too big for comfort. It had grown taller that the house in a matter of a couple of years. You could almost see it growing week by week.

 

[Chukka63]

i felled all trees near my proposed new bungalow before applying for planning permission.problem solved

 

[Thermo]

the eucalyptus ahs a high appetitie for water. its roots normally can spread quite a way, but generally tend to stay nearer the surface. If it is going to be removed it will need to be ground out as the stumps are very good at regenerating after coppicing or felling

 

[freddiemercurystwin]

i felled all trees near my proposed new bungalow before applying for planning permission.problem solved

Yea F**K 'em they've only been there for years! They're only trees afterall.

 

[Thermo]

my feelings as well! Eucalyptus can be quite unstable once they are large. But they will have to go some to knacker up foundations

 

[IJWS15]

You need to see what a dry summer and trees can do to clay.

Had a house in Derby and one year could push a garden cane down 5ft into the cracks in the clay - had to make sure the children did not take any small toys into the garden!

 

[jeds]

A 1.8m foundation assumes the soil volume change potential is low. If the potential is medium or high it should be more in the order of 2.5m.

 

[Shytalkz]

If a tree significantly predates construction and it's in a clay clay soil, then at some point, gradual rehydration of the soil will result in its moisture content becoming greater than that which existed at the time of construction and you can get the opposite of subsidence: heave.

This does depend on the relative age and moisture demand of the tree at the point of its removal: a 9m Euca is what 5 or 6 years old, less than half its mature height, so the effects of removal would probably not be too signficant; on the other hand, if it stays, it will grow and its moisture extraction will increase, hence the reason for the foundation depths required by the BCO.

Chukka63: if you cleared your site of trees to supposedly avoid a (planning) problem, if you're on clay soils and you didn't take steps to take swelling into account, you are potentially storing up structural problems for yourself a few years down the line. And, given the willy-nilly destruction of trees solely for the creation of your edifice, that would be the least that you deserve .

 

[mishel02]

thank you so much everyone for your replys, I feel happier now I have a better picture. foundations ahve now been dug out to 1.8m on all sides and the tree is coming out next week

 

[Thermo]

You need to see what a dry summer and trees can do to clay.

Had a house in Derby and one year could push a garden cane down 5ft into the cracks in the clay - had to make sure the children did not take any small toys into the garden!

i have, i deal with trees every day of the week!