After the massive storm we had here in Plymouth last night, I spent some time holding buckets under the light fitting in the toilet as all the water drained through it out of the roof.
As far as I can tell, the problem is to do with the way the lead valley runnig from the tenement feeds into the main tenement gutter. Essentially, the tenement roof is square, with a drop on all 4 sides, of which one side abutts the main house and is therefore drained by a lead valley, rather than a gutter. The problem arises invery heavy rain when the valley empties too much water into the end of the gutter, which then overflows on both sides - into the yard and also into the roof
. The lead currently overlaps directly into the gutter, so I imagine that what happens is that when the flow is excessive and completely fills the gutter, water gets under the lead and siphons into the roof behind. However, I can't see how to get around this - if the lead doesn't lap into the gutter, the water would just pour over the edge and the guttering needs to be fairly tight under the eaves at that point as it is the highest bit, with the downpipe on the other end.
I may be making it more difficult than it is, but everything we have tried so far hasn't worked - and the only way to tell is to wait for the next big storm sadly!
Any suggestions?
As far as I can tell, the problem is to do with the way the lead valley runnig from the tenement feeds into the main tenement gutter. Essentially, the tenement roof is square, with a drop on all 4 sides, of which one side abutts the main house and is therefore drained by a lead valley, rather than a gutter. The problem arises invery heavy rain when the valley empties too much water into the end of the gutter, which then overflows on both sides - into the yard and also into the roof
. The lead currently overlaps directly into the gutter, so I imagine that what happens is that when the flow is excessive and completely fills the gutter, water gets under the lead and siphons into the roof behind. However, I can't see how to get around this - if the lead doesn't lap into the gutter, the water would just pour over the edge and the guttering needs to be fairly tight under the eaves at that point as it is the highest bit, with the downpipe on the other end.I may be making it more difficult than it is, but everything we have tried so far hasn't worked - and the only way to tell is to wait for the next big storm sadly!
Any suggestions?
