prevent tree roots from clogging sewage drains

[tellme_why]

Hi,
Tree roots get in the sewage drain (see pictures), causing a blockage (loo paper gets stuck into those thin roots).

I am cutting them regularly (every six months) but it's smelly so I want to resolve once for all.

Options are:
1. fell the tree
2. spread some chemicals into the roots but not sure how to; from picture, you can see they are very thin and any liquid would get washed out by loos flushing..

Any suggestion?

 

[tincup]

if you like the tree take some cuttings first
Cut a nick with axe dribble glyphosate into cut should take a few weeks to see results but it works.
Roots damage trees

 

[tellme_why]

thanks I just watched videos about roots killers with foaming agent - it seems one has to apply the chemical every 12months.. I was hoping the chemical would kill the roots for good.. ? If this is the case I would probably take down the tree and kill it with