Great point, I don't know the law, but what if my neighbor came to my house one day, the house that bought few years back and assuming it's 40 year old house, well maintained, assuming the roof was done 20 years ago, my neighbor and I are having a coffee at mid day and roof falls on us and fractures his spine, can he sue me or the contractor that built the roof 20 years ago, or if the roof wasn't done, should he sue me or the builder that built the house 40 years ago assuming they are still around?