Pittwater Council liquidambar wrecks wall - $12,000 repair

Eric Frei

Here's the article:-

Barking up the rogue tree: council-planted liquidambar wrecks wall and wallet - Council - News - The Manly Daily

This is the location.


Council accept no responsibility, well to me the tree definitely looks too close for what appears around a 1m DBH Liquid Amber that has an invasive root system. In addition with a road on one side that would make it's root system more likely to travel toward the wall and parallel with the wall and road.

We need to see where exactly the wall was broken. Also to put a spirit level on it to see if it leans and how much using a plumb bob.

Perhaps some careful hand excavation along the wall foundation would expose roots. I wonder if roots go underneath the wall?

Chances are the wall is not built to retaining wall standards rather just decorative wall on a footing. We know tree roots can exert 145psi of pressure and if sufficient area of root is in contact with the wall there may be enough pressure to raise the wall or tilt it, in addition it could also be subsidence especially if on a reactive clay. If soil moisture levels are lower street side of the wall due to the tree then clay on that side would shrink and likely the wall would lean toward the street.

Either way the repair bill is $12,000 and council have the audacity to serve notice on this guy to repair when they are partly if not all to blame I reckon.

I wonder if the wall was there before the tree?

Now council will debate the classification of Liquid Amber tree roots being invasive. I'm sure if I call them invasive some fool will argue they are not, so best to get another reputable source to call their roots invasive.

I found some from their fellow councils but we all know liquidambers usually have aggressive surface roots similar to ficus trees:-

PDF from Toowoomba council page 5 says so (document attached).

PDF attached from Parramatta City Council states:-
The other issue I believe that is being over looked is repairing the wall and guaranteeing it, with that tree so close by in my experience I doubt any builder would guarantee the wall. In addition it appears the wall is within the tree's SRZ so what happens there for digging etc? In reality there should be a root cut and barrier installed but I think it's all too close to the tree and the tree's stability would be compromised.

So we need some data, hopefully the home-owner will join in and help.

Attached Thumbnails

 

Attached Files

	ToowoombaPlanningSchemePolicy07No03-StreetTrees-2.pdf (308.8 KB, 32 views)
	Parramatta-DA-1536-2004 - Submitted 14 December 2004.pdf (68.7 KB, 78 views)

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