Hi Canary there are things that you can paint on stumps we used something called 'root out' but that was years ago and Mr MB thinks it is no longer for sale. I'd check in a garden centre but make sure you speak to an assistant who knows what they are talking about.

Realistically though the roots that are lifting your path wont suddenly disappear you are going to have to dig those out one way or another.

you need to dril a few holes in the top ot the trunk, big as you can ie half inch ok three quarter better, then get some SBG from the garden center and fill the holes with it this can then get in to the grain and move down to the root's, about seven pound fifty but you can keep the exses to kill things like brambles nettles and is safe with grass

SBK, Cliffo, SBK! Cliffo's right about the method, but I have a short blog on how to do this, step by step, if you want to read it - click on my avatar, select blogs and the one called Tree stump treatments..

I thought it was best applied in the first 48 hours after felling? so will it still work if its longer since canary cut it down?
Also as they rot wont the lifted path sink over time - so perhaps it has to be lifted anyway and then get a root grinder to the stump??

Just be aware that any root poison will take a long time to have any visible effect and the roots of the conifer (possibly leylandii) spread out a very long distance from where the tree used to stand. Where the roots are lifting your path you may have to remove the path and apply the treatment directly on to the part of the root causing the problem, that will rot away and you can remove it and replace your path. You may want to have the main part of the stump remaining drilled out by a tree surgeon as Drc says. That is a quicker way of doing it.

I had not read your blog Bamboo or I would have directed Canary to it , what do they say; I could not have put it better myself lol

If it was a large conifer and is cut down level to the ground it will die anyway. To help this, have a hand axe, cut round the stump about 6inches below ground level, taking off the bark. Lift the paving, cut out the roots that are lifting them, fill in with 6 to 1 mortar mix, replace paving. You will have to do the paving again when the roots rot. Place a large pot or tub over the stump.

In answer to your query, Drc, yes, it will work, doesn't have to be done immediately on cutting down.
And Cliffo, that's fine, how on earth would you know I'd written a blog about it? I did it because it came up so often and it saves having to repeat myself every time...;-)))

Bamboo's blog describes the process exactly and if you look at my photos you will see the result of treating a large cherry tree several years ago.
You can decide which way to go.

SBK is beter effect if mix wiht old engin oil.
A beter is with any acid and oil- as my freend say,"It a reel driler kiler!"
my freend also say-if kill human, it kill plant. alway worth thinkin a bout

I have never heard of a plant dieing of bordom or a broken hart lol

Doctorbob is right. Conifers (except Taxus) will die when cut back to stumps.

Many thanks for all the helpful replies