So people like to have trees growing next to the road, on the pavement. Unfortunately, when some nice species of tree get to a certain size, they tend to produce horizontally growing roots big enough to damage the nearby pavement - and sometimes the road, too. This results in raised or displaced bricks or pavers, and ridges in tarmacadam.

I propose that such trees be surrounded by rings of sacrificial supports. These would need to be capable of supporting load from above, but not so much from the sides or below. I'm thinking some kind of upturned pottery jars may suit (but if this material doesn't have the appropriate characteristics, others may substitute).

Then when the tree roots expand they will impinge on these pots, which will yield space as necessary and preserve the surface above.
-- Loris, Jul 01 2015

When do you get to the good bit, with the chainsaw ?
-- 8th of 7, Jul 01 2015


I was starting to wonder if maybe putting rigid foam insulation under a sidewalk might work for this. Then I considered that this might cause more icing problems in the winter. It seems that most implementations of this idea would tend to insulate the sidewalk from the ground, making winter icing much worse. [+] anyway.
-- scad mientist, Jul 01 2015


As soon as the plant breaks the pot, won't the weight deform the ground anyway? The pot would have to support the weight while being broken.
-- wjt, Jul 02 2015


// The pot would have to support the weight while being broken.//

Yes. I think the important thing is that it breaks in small increments rather than shatter suddenly and completely into fragments. A pot design with crack guides (lines of weakness or holes), or perhaps tapering wall thickness might help. Some experimentation with different pot designs would be necessary.
-- Loris, Jul 02 2015


I believe the use of chalk clay liners would be adequate. Roots cannot penetrate through layers of soil with certain properties, and a deep baked tube of calcium rich soil would be portable and produce a boundary layer that, if left un disturbed, would stop stop root growth for decades while being natural and eventually leaving the soil in a otherwise usable state. The installation would have to be carried out with some care however, as roots would find any aperture eventually. I suspect that an even greater problem in urban areas is the havoc that roots can cause in sewer and drainage infrastructure.
-- WcW, Jul 02 2015



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