Actually, roots do at least two quite nasty things (don't start yawning and you at the back please pay attention :-) The first is to displace whatever's in their way. If a root's under a drain it can grow to the point where it lifts the drain and causes it to burst (the drain that is not the root). Same thing happens to walls and foundations - they get lifted or pushed by the ever increasing size of the root until they crack. The second nasty thing about a root is that when it dies it rots away leaving a void. In other words, if the root under the drain hasn't grown to the point where it has lifted the drain it can still cause it to collapse into the void that the root once occupied. Same result - burst drain. If that isn't bad enough roots can move things around and possibly destroy important archaeological evidence.
By this point you've probably gathered that I don't much like roots. I don't much like mysteries either, and given the choice between a mystery and a fact I'll go for the fact. The Sutton Hoo Ship Burial may have been a mystery while it remained unexcavated but its excavation has provided us with a deeper understanding of early Anglo-Saxon culture, not to mention the preservation of some of the most stunning artefacts ever produce by humankind - artefacts that would otherwise have been lost forever.
