Tree Root Damage

The insured’s backyard tree had potentially damaged the claimant’s property. GEI was assigned to inspect and photograph the claimant’s site, and determine the predominant cause and approximate age of the damage.

Our expert visited the claimant’s residence with our client, the claimant, and his attorney. The claimant explained that a large tree had been removed from the insured’s property. The next photo was taken over the rear fence of the neighbor’s tree before it was removed. It was indeed a large tree.


The claimant felt that it was the roots of that former tree (as shown below) that appeared to him, to be the source of some significant cracking and lifting on the floor of his garage.


His property was a single-family, timber-framed building, aligned principally facing the north south street to the west, with an integral garage to the south.

The actual tree removal date was not known. The “sucker” root growth in the claimant’s yard and associated stem growth above ground was that of Robinia pseudoacacia, or Black locust, a known spreading-root tree unsuitable for confined growth areas, according to Dirr’s “Hardy Trees and Shrubs”. Cracks had formed within the last twelve months in the claimant’s garage and rear yard unreinforced concrete slabs.


The garage doorjamb to the south of the garage had rot at its base (caused by failure to remove water), which resulted in lowering of the doorjamb over time.
The lowering of the jamb, and the sub-tending support post, had resulted in opening of some gapping to the header support over the south end of the garage door, unassociated with the root growth. The claimant also brought to the expert’s attention some areas of baseboard and door trim affected by moisture (rot) within the residence, immediately adjacent to the garage personnel door.

That moisture was not caused by the root growth, but was caused by moisture wicking up through the residence foundation slab. The garage floor slab was separate from the residence foundation slab and the two areas of influence did not have the same causal relationship.

Based on the foregoing, it was the expert’s opinion that the predominant cause of the damage seen, comprised of cracking of the concrete slabs to the rear yard and garage floor, and cracking of the concrete slab to the garage entry, was root intrusion under the slab from the insured’s tree. In addition, the roots had re-established fresh growth on the claimant’s yard by “sucker” roots.

The garage doorjamb rot and the baseboard trim damage within the residence were not related to the tree roots.