Any advice on tree roots, please?

[DrWAnker]

We have just removed old decking from our garden with the intention of putting in a foundation for a log cabin.
But underneath the tarpauline are these massive tree roots which have obviously been looking for water.
I'd rather not have to chop down the tree as it's lovely - was thinking of removing some roots but also worried then the tree will lose stability and fall over? Any experts or anyone knowledgeable have any thoughts?
I've attached a photo!

Depends on what the tree is and how old it is. Some quite small trees can have far reaching roots, some have deep roots, some have shallow roots.
I would be quite concerned about them being near a house or the drains.

Not sure what type, will investigate, but we reckon about 20 years old.
It isn't anywhere near the house the garden is quite large.
Thank you!