Removing trees close to buildings

[Will Heal]

I have been ask to fell and grind the stump of this yew tree.

My only concern is that the tree is very close to the house, on clay soil and is much older than the house.

I'm guessing that if I remove this tree all at once it could cause heave and damage the house.

Would it be best to reduce the tree heavily now then fell in a couple of years time then grind the stump a couple of years after that.

Thanks

Will

 

[Gary Prentice]

If there was a persistent soil moisture deficit when the house was built and its a clay with high plasticity heave is more likely no matter how you do it. 

 

The soil will have been shrunk, house built on top and once the tree has gone will probably expand. 

 

i think the first step would be to get information as to the PI of the soil, not all clays shrink/swell to an extent where damage occurs.

[Marula]

A reduction on the tree would be best if heave is the concern. If the tree is removed all at once it could take up to ten years for the soil to reach saturation, this means that even if the tree is removed now the true extent of heave won't be noticed until much later down the line. Yew is hardy and would withstand a good reduction. It's also a decent size yew and would be a shame to lose it, is there a tpo on it by any chance?

 

 

To add, a good measure is to find out which came first, tree or the house, although in this instance it seems fairly obvious.

[AA Teccie (Paul)]

Reasonably, one could assume that property has been built to take account of the presence of the tree and it's ultimate demise / removal (this is a home-owner / house insurance / structural engineer issue!) That said, my understanding, and (limited) experience, is that heave occurs much (much) less frequently than subsidence and hence, correspondingly, the risk / likelihood is lower...still, we are arborists not engineers so should stick to our brief.

 

Just my ten-penneth. 

[Gary Prentice]

Giles Biddle has a photo of a house still suffering heave after thirty odd years (but probably an oddity) Edit: page 92 of his book.

 

Paul, you'd hope that the house was built post NHBC and had foundations below the level of the trees root influence. 

 

Wonder about the soil soil inside the foundations actually expanding?

 

 

Personally I'd suggest a lot more investigation before theorising about the consequences and Likelyhood or movement.

Edited September 6, 2017 by Gary Prentice
more info and correction

[AA Teccie (Paul)]

17 minutes ago, Gary Prentice said:

Paul, you'd hope that the house was built post NHBC and had foundations below the level of the trees root influence. 

 

Wonder about the soil soil inside the foundations actually expanding?

I think the modifications to foundation design are more than simply 'depth' where potential subsequential heave is involved, e.g. compressible material on the inside in particular. Further, if the soil on the inside was to expand surely that process would have started, and any associated damage evident...just theorizing.

The one example I was involved with was the site of a former woodland copse and whilst extensive measures were included relating to foundation depth nothing for the floors which subsequently all popped up...cost the developers tens of thousands to repair.

[Gary Prentice]

Looking at a few photos Paul, everything is theorising really. 

 

Yes, you're right, I wasn't thinking clearly - if the soil on the inside expands the exterior walls can be pushed outwards with the classic example of lateral movement above the DPC.

 

 

That's a cracking looking tree, shame they built a house there. 

[openspaceman]

20 minutes ago, Gary Prentice said:

 

That's a cracking looking tree, shame they built a house there. 

Yes I was wondering how many of the sawmillers would be onto Will asking for it

[Gary Prentice]

I was tempted, so tempted, to ask the question, "will it be milled?", but thought it better to keep the thread on track. Taking the other thread about forum behaviour into account, I didn't want to upset anyone by taking the proverbial.

[openspaceman]

1 hour ago, Gary Prentice said:

I was tempted, so tempted, to ask the question, "will it be milled?", but thought it better to keep the thread on track. Taking the other thread about forum behaviour into account, I didn't want to upset anyone by taking the proverbial.

Well I'll risk Will's ire by recounting one of the smaller mistakes I made , I'd sold a fair bit of yew for veneering when there was still a slicer at Lydney in Gloucestershire but latterly we were having to export it via Carl Danzer and it was a faff loading timber into curtainsiders for the return trip to Germany. I was running a woodmizer at the time so I decided to add a bit of value to a small piece of Yew, about 15Hft and sliced it through and through at 1 1.4", the log was worth around 200 quid. I never sold a single piece of it and it lay in sticker in the yard till it was redeveloped for an academy.