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foundations with tree problems
Posted: Fri Apr 08, 2011 5:17 pm
by byron
hi there can anyone give me some advise i have just had my plans passed on building a 8 meter by 10 meter garage but wear it is being built down the side of the garage there are very large trees and shrubs wich are about 3 meters away from the side of the garage will i have to have special foundations can anyone give me some information on this please
trees
Posted: Mon Apr 11, 2011 7:04 pm
by welsh brickie
No just cut the roots when you see them in the foundation
Posted: Wed Apr 27, 2011 8:41 pm
by andy01
you can use strip foundations.
you will need to identify the tree type. and use nhbc 4.2 to work out the depth for the bottom of the foundations, which may be as deep as 2.5m down. compressible material may be required an the inside face of the founds and a slip membrane on the outside.
a suspended floor with adequate clearance will be required dependant on the volume change potential of the soil.
dependant on the tree type you may be too close too use nhbc 4.2
during planning a tree officer should have reviewed your plan. they may decide the tree is a worthy specimen and will insist on founds that do not harm the tree roots in which case a susended raft supported by pads down to the required depth (bearing capacity) may be required.
chopping down the tree and pretending it was never there will not stop the inevitable dessication and heave, and the structure will suffer from subsidance/ severe cracking
however your builder will either not know the above or not care as its too much work and so will just do as welsh brickie said - no this is not a dig at you
tree roots
Posted: Thu Apr 28, 2011 11:43 am
by welsh brickie
[quote="andy01"]you can use strip foundations.
you will need to identify the tree type. and use nhbc 4.2 to work out the depth for the bottom of the foundations, which may be as deep as 2.5m down. compressible material may be required an the inside face of the founds and a slip membrane on the outside.
a suspended floor with adequate clearance will be required dependant on the volume change potential of the soil.
dependant on the tree type you may be too close too use nhbc 4.2
during planning a tree officer should have reviewed your plan. they may decide the tree is a worthy specimen and will insist on founds that do not harm the tree roots in which case a susended raft supported by pads down to the required depth (bearing capacity) may be required.
chopping down the tree and pretending it was never there will not stop the inevitable dessication and heave, and the structure will suffer from subsidance/ severe cracking
however your builder will either not know the above or not care as its too much work and so will just do as welsh brickie said - no this is not a dig at you[/quote]
What you mean is a TPO a (tree preservation order) if the tree was an endangered species or was considered to be of historic value an order would be imposed to stop any construction within a given boundry planning permission would not be permitted,this does not seem a problem
Re: trees
Posted: Thu Apr 28, 2011 7:52 pm
by elwood
[quote="welsh brickie"]No just cut the roots when you see them in the foundation[/quote]
Hi
This is very bad advice and if followed in time would cause major problems .
Bye
Posted: Wed Jun 08, 2011 8:37 pm
by andy01
Welsh brickie
from the jobs i have been involved in with lots of trees on site and no TPOs, the tree officer has stated what he wants and what he doesn't want to keep, based on quality of specimens
maybe they aren't involved in small scale builds unless there is a tpo.
dont know as i'm not a planner or tree specialist