I have a 10 year old conservatory. A leak has developed from under the glass where the glass sits on a seal. From what I understand the glass sits on rafters that has a rubber gasket. the weight of glass plus the compression of the outer cover is supposed to seal it and the cover on top is supposed to also have a gasket preventing water ingress. I need to go up on the roof to check, but wanted to know could be the possible causes? and are there any fixes if the seal is leaking?