Tree 2
34This is a mature Bangalay growing near the edge of the unretained bank along the common boundary. This tree is some metres to the east of T1. The tree is a healthy specimen and a number of branches overhang the applicants' dwelling.
35The applicants contend that in December 2007, a large live branch fell from this tree and caused damage to the glass roof and tiles of their dwelling. The SES was called to remove the branch and cover the roof.
36On 23 February 2013, a dead branch fell from a nearby tree and pierced the roof and ceiling. Photographs in the applicants' bundle of evidence show the branch through the roof and ceiling.
37The applicants are concerned that further branches may fail and cause future damage or injury.
38Apart from the risk of branch failure, the applicants are also concerned that roots from this tree may have caused or could cause damage to their dwelling and associated structures.
39Given these concerns, the applicants are seeking orders for the removal of the tree.
40In regards to the above ground parts of the tree, on various visits to the applicants' property, Ms McKenzie observed the points from which she considered the 2007 and the 2013 failures occurred. Since the time of her last inspection in April 2013, the respondents engaged an arborist to remove dead wood from the eucalypts on their property, including the sections overhanging the applicants' property. (The trees were pruned in June 2013.)
41Subject to an assessment of the impact of root pruning, in her report, Ms McKenzie recommends the removal of dead wood down to 20mm in diameter as a means of reducing the risk of damage to the applicants' dwelling.
42Mr Hartley's report appears to question whether the 2013 branch fell from tree 2. He considers the way in which the branch fell and punctured the roof to be unusual and does not warrant the removal of the tree.
43During the hearing we were shown the likely point of failure of the 2007 branch. The location of the point of attachment and the relative location of the glass section of roof would suggest that it was probable that the branch did fail from that point. While there is no photographic evidence of that damage there is no suggestion that the event did not occur.
44Because of the pruning in June, the likely point of failure of the 2013 branch, indicated by Ms McKenzie, has been removed. However given the location of the damaged section, the fact that Tree 2 overhangs that part, and the branch is clearly that of a eucalypt, we are satisfied that Tree 2 has caused damage to the applicants' property and s 10(2) is satisfied in regards to this tree.
45Before considering what orders should be made, the other concern the applicants have about this tree is in regards to potential damage to their dwelling because of its roots.
46According to her report, Ms McKenzie visited the applicants' property in January 2012. She viewed the four trees growing on the respondents' property. She states in her report that, amongst other things, she gave a verbal opinion that roots from a tree on the neighbouring property were lifting a concrete slab in the applicants' backyard and were likely to be the primary cause of damage to a bedroom wall.
47The applicants engaged Mr Paul Moxham, a licensed builder, to inspect the applicants' dwelling and nearby areas for evidence of any damage that may have been caused by roots from trees growing on the adjoining property.
48Mr Moxham's report dated 8 April 2013 includes photographs and a location diagram of the roots he found beneath the south-western portion of the applicants' dwelling. The roots and accompanying photographs are numbered. He identifies Tree 2 as the likely source of the roots but states an arborist should verify this.
49Mr Moxham considers that from his experience, the cracks may continue to worsen with the possibility of structural damage. He recommends a structural engineer assess the dwelling.
50After a further inspection of the subfloor and area beyond on 12 June 2013, Mr Moxham checked the roots to determine whether they were dead or alive. The diagram records where the roots were seen on the surface beneath the floor; it is possible that they are sections of the same root/roots.
51Under bedroom 2, Mr Moxham noted four roots between 20 and 40mm in diameter. Only one 25mm diameter root (no. 6) was alive and no structural damage appeared to have been caused by any of the roots although Mr Moxham stated that a root had displaced a pier by about 30mm.
52Roots were observed under bedroom 3. Two of the roots were measured - one was 50mm and the other 70mm in diameter. None of the roots below bedroom 3 were alive. Mr Moxham's report includes photographs of cracks in the internal and external sections of the double brick outer wall beneath the window of bedroom 3. The wall has since been repaired.
53Photograph 16 shows a woody root outside bedroom 3, adjacent to a concrete slab in the applicants' garden. The concrete retaining "wall" is cracked in the vicinity of the root. This root was alive but severed near the wall. The root is consistent with being from a Eucalypt.
54We observed a woody root, consistent with being from a Eucalypt, growing under and lifting the concrete slab.
55Ms McKenzie considers that the roots Mr Moxham observed beneath the house and those she notes in her report are most likely from Tree 2 rather than from trees 3 or 4, given its location in relation to the dwelling and slab. In her opinion, cutting the exposed roots beyond the outer edge of the slab is unlikely to have any significant impact on the health or stability of the tree.
56Mr Hartley's report considers various aspects of root growth. He questions when the cracking of the building occurred and whether the damage occurred after the roots died. A considerable section of his report deals with root pressure calculations. While he agrees that roots could have lifted the concrete slab he questions the ability of the roots beneath the house to have caused any damage.