| Author | Message | ||
     Sarah |
I recently bought a house with a 97 year old graduated slate roof which has had neanderthal care over the past 30 years. The front porch receives a lot of water from the main roof and dosn't have much of a pitch. There is a persistant leak out of the wooden beam underneath on side of the porch roof which the roofer thinks is caused by rain angling in sideways, between the slates and the fascia. It used to have cement under the slates at the edge which had hardened away from the slate. My roofer took out that cement, replaced part of the rotted fascia with new wood and says that there is some special expandable, breathable foam from England that he is ordering to block that rain. Has anyone heard of this product or have any knowledge to share about leaks at the drip edge. Thanks for any advice. Sarah | ||
| Walter Musson |
It might be more appropriate to remove several courses of slates at the eaves and replace the underlayment ,then re-slate this area.You might even consider a copper drip edge to help matters. | ||
| admin |
Expandable foam to stop leaks on a slate roof is an unknown technique and unlikely to work. If you think about it, why wouldn't the drip edge be leaking all along the entire length of it if the problem is related to design or installation? If it has persistently leaked at one spot, perhaps there is a flaw at that spot - a broken slate, an exposed nail head, a crack, a hole. This is what I have found in my experience. Leaks are caused by specific problems in slate roofs such as mentioned above. The problem has to be identified, located, and then repaired. Sometimes, for example, a repair slate is installed that is too short (e.g. an 18" long slate is used where a 20" long slate should have been used). The short slate robs the roof of headlap and a leak occurs there at that spot. This is invisible from outside the roof until the offending slate is pulled out and its actual length can be seen. It takes experience with slate roof repair and restoration to successfully find leaks of this sort if the leak has been persistent or chronic. | ||
| Walter Musson |
When large amounts of water from a roof above are dumped onto a lower porch roof that has a shallower pitch any problems as Joe talks about are exacerbated by the extra amount of water. My suggestion was similar to Joe's in that by removing several courses of slates you would discover the problem and correct it during the re-laying process. If the roof is old it can't hurt to refresh the underlayment in the area you might re-lay. | ||
| Ted Wetzel |
This comment comes from an amateur but hey, it's a free country. Even with the porch roof fixed it would make sense to me to put a gutter on the upper roof? Obviously if the lower roof is done properly it's not an issue, it just seems like something I would do to minimize the damage from any future leaks. | ||
| Sarah |
Thank you all for your suggestions - At the drip line there is quite an elaborate crown molding which comes pretty close to the edge of the roof- is it possible that this could be directing water in when rain comes at an angle - and why was that space in the drip edge all around the house filled with cement? The roofer has been looking and looking for the problem - there are lots of slates that look like the problem but so far none of them has led to the solution. We are getting a new gutter - the old one was dumping water on the roof. Sarah |
