Chances of heave if willow is felled?

[boris360]

Hi all,

 

I'm looking for advice on whether I need to get an arborist's report before a willow is felled.

 

The willow is at the bottom of my garden.

The distance from my garden retaining wall is 21 metres.

The tree is downhill from the house on a slope of approx 7º.

It's on clayey, loamy soil (I think).

The tree is mature.

The tree was there before the house was built.

The house is 14 years old.

 

I've spoken to a structural engineer, the council tree advisor and also a tree surgeon all of whom say the tree is too far away to cause heave or any other issues. I thought I'd ask here because I expect there are more knowledgable people on this type of issue.

 

I've read about heave on these forums and also about how bad willows can be hence my caution but I'm not sure how far away a willow can be before it's no longer a problem.

 

Any advice would be much appreciated. Thanks.

[Rich Rule]

I would have thought that the amount of water that tree would normally utilise would be an issue after it has been removed.

 

Your garden may be perpetually flooded during wetter times.

[detritus21]

It is well away to not cause heave. If it was an nhbc build the tree is well outside the zone of influence with regards to potential damage to foundations/heave.

[Mesterh]

If a tree that size in that position caused heave there would be an awful lot of us in big trouble!

[benedmonds]

.....there is not a lot you can do about it - after all the tree may die so what are you going to do then?

 

This is the long and short of it.. even if there is heave as far as I am aware you just have to fix the problems so there is no point faffing with engineers reports.

[donnk]

you are fine. If you have clay then building control would make the footing 2m or more to compensate.

 

I've seen loads of footings on old buildings of 3 stories of just 40cm!

[Wood-be]

Blimey, hands up who thinks he is making a big deal out of nothing. That tree is to far way to cause any structural defects with the wall or house. The sure fire way of covering your back if your really worried is to reduce it back over 5-7 years. That is what structural engineers will say as that is what they have advised many of my clients with trees which are three times the size and 6 meters away from the house. This way the ground will heave naturally and cope with the change in water volume ect ect.

 

Regarding your footings if you are on clay and your house was built properly it may be on piles with heaving voids around them and around the connecting footings. The best way to think of it is if clay is actually water. You either float on it (just like all old light weight timber frame houses do) or you put your feet on the bottom of the pond or sea and hold you house up ontop of the waters surface.

 

It's up to you I personally would advise a 5 year reduction posibly leaving it pollarded. But I wouldn't see any problem in just pollarding it from the start.

 

If it's diseased then when it dies figures crossed your house and wall won't float off down the garden 😀

 

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[kevinjohnsonmbe]

The biggest problem you may have is knowing the difference between good advice and speculation....

[Adam M]

Blimey, hands up who thinks he is making a big deal out of nothing. That tree is to far way to cause any structural defects with the wall or house. The sure fire way of covering your back if your really worried is to reduce it back over 5-7 years. That is what structural engineers will say as that is what they have advised many of my clients with trees which are three times the size and 6 meters away from the house. This way the ground will heave naturally and cope with the change in water volume ect ect.

 

Regarding your footings if you are on clay and your house was built properly it may be on piles with heaving voids around them and around the connecting footings. The best way to think of it is if clay is actually water. You either float on it (just like all old light weight timber frame houses do) or you put your feet on the bottom of the pond or sea and hold you house up ontop of the waters surface.

 

It's up to you I personally would advise a 5 year reduction posibly leaving it pollarded. But I wouldn't see any problem in just pollarding it from the start.

 

If it's diseased then when it dies figures crossed your house and wall won't float off down the garden 😀

 

Sent from my C6903 using Tapatalk

 

You can't creep up on it and hope the ground doesn't notice you nibbling bits off the tree every few years.

[Wood-be]

You can't creep up on it and hope the ground doesn't notice you nibbling bits off the tree every few years.

Um not sure what your getting at. If you reduce a tree over a period of time (you can reduce the roots aswell vat that's a whole different ball game) then you are allowing water to re-wet the soil under the tree slowley and minimise the effect of heave.

 

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[donnk]

I think the original poster has a valid point to check. mostly if the footing was post the great drought of 1977 then you probably are ok. A lot was learned from this as clay soils shrank as the water table dropped, this left many footings floating and cracking.

 

This was the driver to make 2m+ footings. Nowadays even with no clay, if there is any tree withing 5m then 2m+ is the norm. Building control/structural engineers just dont run the risk of litigation so make you dig deep.

 

An interested read about it for tea break.

 

http://www.geplus.co.uk/download?ac=1423914