A
Anonymous
Guest
That's okay David; it is nice to be of some help with the ‘moss on roofs’ query.
It is easy to look on these small, seemingly insignificant things, like moss on a roof, as of no particular need for concern - that is until people start to look a lot closer at things.
It is quite safe to say that common lichens and mosses will do no particular harm to a mineral roof, if for instance a stone roof is delaminating then frost and ice will do a lot more harm than say moss. Whereas root and leaf growing plant life can be utterly destructive. In fact in most cases, a ‘weathered’ roof can look much more in keeping with the environment than a sparkling clean one (anyway, it adds to the insulation!).
But sure, pluck out anything with roots and stalks and leaves as they could wreck a good roof.
On the other hand! Traditionally built roofs are not ‘patios’ or ‘concrete driveways’! They are constructed entirely differently, with a varying range of different materials, in an entirely different manner. Acidic, type weed killers and perhaps other types of cleaning agent could well adversely affect some parts of a roof in the longer term, i.e., leadwork, fixings, underfelt, woodwork, surface finishes, etc. However, much more importantly, inexperienced ‘pressure washing’ is far more likely to do an awful lot more damage in the short term! (I am sure a commercial outfit would justify any costly damage as: “a fault waiting to happen” and “aren’t you fortunate we have found it”!)
As an experienced Slater & Tiler I would not normally even consider, ‘pressure washing’ a roof, period – only under ‘extreme’ circumstances and then selectively under low-pressure, and with a great deal of caution and know-how.
Thanks for inspiring this further thought on the subject David, it could hopefully put someone off of pocking their heads over the parapet and pressure hosing their roofs off.
Bryan
It is easy to look on these small, seemingly insignificant things, like moss on a roof, as of no particular need for concern - that is until people start to look a lot closer at things.
It is quite safe to say that common lichens and mosses will do no particular harm to a mineral roof, if for instance a stone roof is delaminating then frost and ice will do a lot more harm than say moss. Whereas root and leaf growing plant life can be utterly destructive. In fact in most cases, a ‘weathered’ roof can look much more in keeping with the environment than a sparkling clean one (anyway, it adds to the insulation!).
But sure, pluck out anything with roots and stalks and leaves as they could wreck a good roof.
On the other hand! Traditionally built roofs are not ‘patios’ or ‘concrete driveways’! They are constructed entirely differently, with a varying range of different materials, in an entirely different manner. Acidic, type weed killers and perhaps other types of cleaning agent could well adversely affect some parts of a roof in the longer term, i.e., leadwork, fixings, underfelt, woodwork, surface finishes, etc. However, much more importantly, inexperienced ‘pressure washing’ is far more likely to do an awful lot more damage in the short term! (I am sure a commercial outfit would justify any costly damage as: “a fault waiting to happen” and “aren’t you fortunate we have found it”!)
As an experienced Slater & Tiler I would not normally even consider, ‘pressure washing’ a roof, period – only under ‘extreme’ circumstances and then selectively under low-pressure, and with a great deal of caution and know-how.
Thanks for inspiring this further thought on the subject David, it could hopefully put someone off of pocking their heads over the parapet and pressure hosing their roofs off.
Bryan