Felling two mature oak trees near house

[ashley horner]

Hi everyone,

 

I have two mature oak trees which I am thinking of felling in order to create a driveway for parking a couple of cars.  The photo shows the two tree and their proximity to the house (approx. 7 meters).  The house was built in 1956 and I assume that the trees pre-date the house, neither of the trees have a TPO.

 

I am based in Woking, Surrey and the online Cranfield soil map says that I have "slowly permeable seasonally wet slightly acid but base-rich loamy and clayey soils".

 

The trees are on a raised bank with a road on one side and an area of grass on the other (between the trees and the house).

 

Now, I will say that I really don't want to fell these two trees as they are truly magnificent, however we do need to be able to park our cars and the driveway barely fits one car.  I know that the definitive answer is to have someone investigate this on-site but I would also welcome your expertise, experience and any guidance.

 

So, my questions:

 

1. do I need to take out the trees at all?  The driveway will need to be dug down 200mm, the driveway contractors that I have spoken to are more than happy to cut through the roots but they are not experts.  I have dug at approx. that depth running from the tree to the house and can see a few roots, some approx. 1.5 cm in diameter, others much smaller

 

2. if I did fell the trees, what would you think the likelihood of heave is?

 

3. lastly, what type of person is best to advise on this?  I have searched for soil analysis on google but I just come up with companies that undertake large commercial projects

 

Any thoughts/comments would be really appreciated.

 

Thanks,

 

Ashley

[openspaceman]

On 10/11/2019 at 18:22, Rough Hewn said:

One way membrane, 150mm celltech stuff,
Fill it with pea shingle.

I think most votes go for this type of containment, I've no experience of it but see plenty of hardstands under trees locally  so I think it would work. I like the idea of pea shingle rather than limestone scalpings as this will be an acid soil and pea shingle will not leach calcium ions into the soil and alter the environment for the tree roots.

 

I would talk with the highways people  to try and prevent further erosion from vehicles mounting the kerb.

[Mick Dempsey]

I suppose a lot depends on how much you want to keep the trees.

 

I would have thought as you can already get two cars on there, that some light scraping of topsoil, followed by a liberal dumping of gravel would suffice, rather than going the whole 9 yards by digging up and putting down hard standing.

 

 

[ashley horner]

yes, gravel is the plan and I had hoped to do just that.  Been a bit of a learning curve, but it needs a sub-base of 150mm and 50mm gravel, and that is from solid ground not lose top soil

[MattyF]

I would be looking at this if putting gravel down , you won’t have to mess with soil levels or damage tree roots with ground preparation and it would alleviate some of the roots compaction in the future

Gravel Driveways | Plastic grids for gravel drives & car parking

WWW.MATSGRIDS.CO.UK

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For gravel driveways, these plastic grids are perfect at retaining gravel and reinforcing the ground. Reduce sinking, rutting and migration on gravel driveways

[ashley horner]

thanks, I will look in to the plastic grids but I thought they still needed a subbase and therefore requires digging down.

 

Just to refine my original post, I've looked at the British Geological Survey website and I am on bagshot sand if that helps.

 

Ashley

[doobin]

8 hours ago, ashley horner said:

 

Now, I will say that I really don't want to fell these two trees as they are truly magnificent

 

If I had a pound for every time a client said that...

 

Actually, we should have a rule here. Every time someone says that in the Homeowner's section- a tenner in the charity pot! ?

 

If you really actually care about the trees (?) then a slight scrape of the topsoil, some of that plastic grid and then some gravel will give you a perfectly serviceable driveway, especially on free draining sand on a bank like that. Might not be totally level, might require a bit of maintenence every now and then, but do you care about the trees or not?

 

 

Edited November 6, 2019 by doobin

[Gary Prentice]

22 minutes ago, ashley horner said:

thanks, I will look in to the plastic grids but I thought they still needed a subbase and therefore requires digging down.

 

Just to refine my original post, I've looked at the British Geological Survey website and I am on bagshot sand if that helps.

 

Ashley

You probably realise that you don't get subsidence with trees on sandy soils? Ergo, no heave if you remove trees, which then allows a desiccated soil to expand i.e. heave.

 

I'm not really following where you're intending to create new parking areas from the photo, but to avoid digging the common way forward to avoid damage to tree roots (no-dig solution) would be Cell TRP. 

 

For cars & light vans only, the minimum thickness is 100-150mm - straight on top of the existing soil. Layer of geotextile then permeable surface on top.  Cellweb guarantee that it prevents damage to trees, I think that they'll if defend against TPO contravention claims when it's installed properly, so they're pretty confident.

 

I can't remember now but I think I've read about some issues with the geogrid parking grids still causing damage to the underlying tree roots. Don't quote me on that though, just something in the deep dark recesses of my mind.

[MattyF]

Your right Gary I would go with Cellweb over what I posted the link too... this should of been what I posted !

Cellweb®TRP - Cellular Confinement System

WWW.GEOSYN.CO.UK

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Cellweb®TRP is the only guaranteed, no dig, cellular confinement system specifically designed and sold for tree root protection (TRP) applications.

[ashley horner]

1 hour ago, Gary Prentice said:

You probably realise that you don't get subsidence with trees on sandy soils? Ergo, no heave if you remove trees, which then allows a desiccated soil to expand i.e. heave.

I see - no, I didn't realise it is 100% not an issue.

1 hour ago, Gary Prentice said:

I'm not really following where you're intending to create new parking areas from the photo, but to avoid digging the common way forward to avoid damage to tree roots (no-dig solution) would be Cell TRP. 

 

The 2 cars are parked on the grass now which is where the driveway will be created.  The grass is rapidly turning in to a mud pit.

 

Thanks for the Cellweb recommendation, I will investigate.

 

1 hour ago, doobin said:

If you really actually care about the trees (?) then a slight scrape of the topsoil, some of that plastic grid and then some gravel will give you a perfectly serviceable driveway, especially on free draining sand on a bank like that. Might not be totally level, might require a bit of maintenence every now and then, but do you care about the trees or not?

Thanks doobin.  Strange as it might seem, those 2 guys have been here longer than the house or me, so I feel like they have a right to remain in place.  ?

 

There is a slope up from the existing driveway to the part where the cars are parked, I know the grid systems are designed for slopes but over time do they just become visible as the gravel shifts?

 

Ashley

[dig-dug-dan]

You do not need to dig out as much in the circumstances, light scrape, avoid roots, geo textile down, min hardcore, then gravel. You can use grids , but you must get a flat surface to put them on