Cutting Copper Beech Roots for a trench?

When I had a field drain installed at my house in the US (to reroute storm water to the road), there was a very large conifer with roots thicker than yer arm just where they needed to trench. So they dug that bit by hand and left the roots intact.

I am not a tree surgeon, but the rule of thumb for tree roots is that they extend out as far as the leaf canopy above. I would think there is a real risk of damaging the tree if you cut into them to the degree you're suggesting, even to the point of having the tree blow over in a gale, having lost a significant part of is anchorage, let alone damaging its ability to take up water and nourishment, especially in dry weather.

Have you considered digging a decently constructed soakaway close to the bottom of the downpipe carrying that rainwater? In my previous property, the rainwater soakaway was basically an underground box, about 1.5 metres cubed internal dimensions, of loose-laid concrete blocks, this sort of thing

But there are probably detailed designs of soakaways on the Internet that would conform to today's building regulations. Most things are regulated these days.

Up to a fifth - probably irrelevant.

Especially in heavy soils. Beech does suffer in dry years on chalk though

I have had five trees blow over in gales in my garden. Not one of them had cut roots, though some had rotting roots.

Have you checked to see if there's a TPO on this tree?

Although it would cost money, specialist firms can put pipes in using moles; they should be able to do this without damaging the roots by going under them (most tree roots are surprisingly shallow).

mature beech trees like that don't react well to changes . The rule of thumb for a root protection area on developments used to be no work withing four times the girth.

the updated advice is in

If you dig the trench carefully and given much of the area has been compacted by the car turning area I think you are probably safe.

Could you simply dig the trench carefully and avoid damaging any roots? You should be able to pass a pipe under the roots in most cases.

See

I'd not be doing it, 2 thirds of the trees in this road died after Virgin used a trench cutter to make the place for their ducts to run.

How bendy are the roots, If you can just part them and move them a bit while the tree is not so active, then you may be able to get away with it. There are rules about trees, so you need to talk to the local authority, who also may know of a local tree surgeon who can advise. Brian

Damage is damage. Minimise it by putting the run further from the tree, maybe the other side of the wall, from where your wheelbrrow is.

Roots are invasive re your pipework...