Tree roots and pipes - a question

[Kveldssanger]

We all know that tree roots getting into pipes is considered a bad thing. I wonder, therefore, whether a middle ground could ever be struck. Would it be possible, for example, to create a pipe that comprises of two compartments - one central pipe, sitting within a larger outer pipe. In the outer pipe, moisture from the inner pipe could perhaps be allowed to move into it via some sort of osmotic pressure, where tree roots can then exist and draw up the moisture without the inner transporting pipe being blocked with roots (at least, to any marked degree). This would be most ideal if the joins of the inner pipe were directly central between two joins of the outer pipe, thereby meaning tree roots would need to travel great distances to reach a join to infiltrate the inner pipe.

 

Is this possible, at all?

[kevinjohnsonmbe]

Not until you find a builder / ground worker that has the slightest interest in anything other than getting to the pub by 5?

[Kveldssanger]

True. I suppose these could be manufactured to spec, though cost would be the issue if the idea is even feasible!

 

In an ideal world...

[Justme]

If they can get in the first pipe by design they will get in the second too.

 

If you want a twin pipe system make both root proof.

[kevinjohnsonmbe]

Not until you find a builder / ground worker that has the slightest interest in anything other than getting to the pub by 5?

 

It wasn't a flippant reply Chris despite maybe seeming that way.

 

And probably a bit unfair to the ground worker actually since it would be the project designer / architect that would have to 'buy-in' rather than the bloke that puts the pipe in the ground.

 

I'd guess the problem probably lies in getting someone to have sufficient foresight (and the willingness to build in additional cost at build stage to ameliorate something that might not materialise for 10/20/30/50 years hence (after they've received their Knighthood for services to architecture and before the problem starts to materialise....)) Or even to find enough people to understand the potential for conflict between trees and development....

[bumble B]

Pipes infiltrated by roots make money. To make one solid pipe that doesn't deteriorate, bends and flexes is possible but won't make money. Don't invent a pipe that encourages roots.

[monkeybusiness]

I think the twin-wall adds massive complications. What you need is a semi-permeable pipe wall that allows moisture (but not roots) through. Similar to old fashioned clay pipes, but with root-proof joints. This way the roots could envelope the outside of the pipe and exploit the water that finds its way out through the walls. It would be a difficult sell though - Osma (etc) offer a decent root-proof solution when installed correctly - trying to get people to install drainage that promotes root growth may be tricky...

[Swampster]

Is the vector for root access to the pipe not physical damage in most cases? Or poor jointing at any rate, degraded by either time, movement or poor workmanship? The presence of roots which surround services is attributable to the raised moisture levels due to condensation resulting from the temperature differential at the interface between ambient ground moisture and pipe content temperature.

Therefore surely to twin wall pipes will mitigate the issue simply by providing sufficient thermal insulation to reduce or prevent condensation forming on the outer surface of the pipe. Alternatively the use of modern materials such as MDPE or polyurethane would prevent ingress of roots in the first instance. Admittedly this will not stop old systems being invaded but their subsequent replacement with more resilient materials will mean roots cease to be an issue?

The fringe benefits of this would be open access to the increased moisture for the roots and a free drink on us.

[Gary Prentice]

I think one of the initial problems to address would be the suitability of the media surrounding the pipe work. Typically urban soils are compacted to a degree inhospitable to root growth, but a pipe run is less compacted and roots take advantage. David H. Posted a photo a year or two back of roots in disturbed soil at an outdoor pool which was a classic example )

[Kveldssanger]

I think the twin-wall adds massive complications. What you need is a semi-permeable pipe wall that allows moisture (but not roots) through. Similar to old fashioned clay pipes, but with root-proof joints. This way the roots could envelope the outside of the pipe and exploit the water that finds its way out through the walls. It would be a difficult sell though - Osma (etc) offer a decent root-proof solution when installed correctly - trying to get people to install drainage that promotes root growth may be tricky...

 

Yeah I know what you mean. As I say, just a thought that sprung into my head. Theoretically, it's great, though logistically and economically perhaps not so much.

 

 

 

Is the vector for root access to the pipe not physical damage in most cases? Or poor jointing at any rate, degraded by either time, movement or poor workmanship? The presence of roots which surround services is attributable to the raised moisture levels due to condensation resulting from the temperature differential at the interface between ambient ground moisture and pipe content temperature.

Therefore surely to twin wall pipes will mitigate the issue simply by providing sufficient thermal insulation to reduce or prevent condensation forming on the outer surface of the pipe. Alternatively the use of modern materials such as MDPE or polyurethane would prevent ingress of roots in the first instance. Admittedly this will not stop old systems being invaded but their subsequent replacement with more resilient materials will mean roots cease to be an issue?

The fringe benefits of this would be open access to the increased moisture for the roots and a free drink on us.

 

Roots usually get in via joins / cracks. Indeed, the condensation, reduced compaction around pipes (especially beneath), and the much warmer surrounds of foul pipes compared to the nearby soil (all that human waste - gives off some heat!). If the inner pipe was made of HDPE or what have you it could, in theory, work more effectively, and indeed the trees could still use moisture that resides within the space between the two pipe walls. I was trying to think in a way that balances the needs of proper underground pipework and giving the trees the moisture usually lacking in urban areas, as hardly anywhere has stormtmater irrigation reservoirs below the surface to support trees.

 

 

I think one of the initial problems to address would be the suitability of the media surrounding the pipe work. Typically urban soils are compacted to a degree inhospitable to root growth, but a pipe run is less compacted and roots take advantage. David H. Posted a photo a year or two back of roots in disturbed soil at an outdoor pool which was a classic example )

 

Got a link for that photo?