Tree Root Ingress To Drainage Systems
Tree roots are probably the biggest cause of blockages within drain, pipe and sewer systems in the UK and unfortunately a root damaged drainage system can often lead to more than an overflowing manhole or grid, many subsidence related problems can be attributed to a root damaged and leaking drainage system.
For this reason most surveyors undertaking a house pre-purchase survey would recommend that the drains be inspected if they are in fairly close proximity to any trees, shrubs or hedges.
How Do Tree Roots Get Into Your Drains
The tree roots gain access to the drain system via the pipe joints, fractures, cracks and through inspection chamber walls and benching. The majority of the drainage systems within the UK are constructed from collar and spigot vitrified clay pipes jointed using sand & cement, these joints offer little resistance to fine tree roots which once inside develop into tap roots and root masses which then reduce the internal bore of the pipe. More modern systems installed using rubber sealed couplings are still prone to root ingress if not protected by a root barrier or surrounded in concrete, though as modern systems are supposed to be flexible surrounding the joint in concrete is generally frowned upon.
Why Tree Roots Enter Your Drains
it is generally thought that condensation that naturally occurs on the outer wall of the drain pipe, or moisture from leaking drain joints attract tree roots looking for a good nutritious feed, though i still prefer to tell customers that the tree`s find the drains because they can here the running water inside.
Disturbed ground such as trenches excavated for drains, services and house foundations make easy traveling for a root system compared to the adjacent virgin ground, the same applies for granular and porous sub-bases for driveways and patios.
When we excavate a root damaged system even at two or three metres deep you can clearly see where the roots have followed the line of the original trench wall down to the drainage system, you will then often find one large tap root running the length of the drain with smaller roots branching off at each collar.
How Do You Repair Root Damaged Drains
If the roots have accessed the system via its joints and there has been no major displacement to those joints the system can be root cut and in many cases relined, if there has been major displacement to the joints or severe fracturing then excavation may be the only answer.
On most domestic systems given the number of bends and junctions you get over fairly short distances it is often a mixture of the two repair methods are required.
If you have a system that has severe ingress and major displacement of joints but you can not excavate it a pipe bursting method can be used, assuming there are no lateral connections or sharp changes in direction and you can winch a line through the system.
Are You Insured For Tree Root Damage To Drains
You should be unless you have some obscure bricks and mortar policy that states otherwise, tree root ingress to drains has always been an insurable risk however since the down turn in the economy one or two companies are trying to knock a few tree root related drainage claims back.