| Author | Message | ||
     Eric Braymer Junior Member Username: Braymer Post Number: 19 Registered: 09-2008 |
Thanks very much, these are things I hadn't thought of. The examples I talked about did have ALOT of tree cover (Maples mostly)and I have been told of certain trees adding to degradation. Also the quality of the original slates on the last few jobs was not very good in the first place, all thin semi weathering green-grey (sea green) with about 100yrs on them. One repair on a north facing side also had dormers above the main roof that dropped more water on the spots that I had to work on, now that I think of it. Maybe Richard Pryor will load up some photos of his black/green roof. | ||
| Walter Musson Senior Member Username: Walter_musson Post Number: 104 Registered: 07-2006 |
My experiences in Maine are this - our native stone is known for its hardness. I can't usually tell after I've removed for salvage 100 year old slate -- from which side it's been removed. Slate quality is similar , but the iron nails used back then are always in worse condition on the North side. The reasons Eric gave earlier lead to deterioration of the nails so more slates start to "weep" | ||
| Kurtis Hord Senior Member Username: Kwhord Post Number: 110 Registered: 10-2006 |
Same issue here, restoring the south side of a roof right now with peach bottom stone that is in bad shape compared to the stuff on the north side. I've never seen hard peach bottom stone deteriorating like it is on this roof. It is behaving more like PA black but it is definitely Peach. | ||
| Joe Jenkins Senior Member Username: Joe Post Number: 333 Registered: 07-2006 |
Eric - that's exactly opposite my own experience. The slates on the north side of the roofs are typically in better condition than those on the south sides and may have 20 more years left in them when the south side is shot. We always prefer to have the slates from the north side when we salvage them. Trees, leaf fall, moss, etc. have their own effects, but it seems that the heat of the sun causes the stone to chemically degrade faster. | ||
| Eric Braymer Junior Member Username: Braymer Post Number: 18 Registered: 09-2008 |
I hate to deviate from the original text string, but had a point / question about north-facing surfaces or roof sections that are usually shaded. I had seen many times that the side that gets less sun is more deteriorated from (my guess) moisture that stays on the slates. This I have seen on north facing fields and also on sections that get no sun such as shady areas under tree canopy or parts that are generally shaded from other buildings, etc. These areas seem to have more moss, lichens, and other signs of moisture that has kept the slates wet longer than the sunny side. The last 3 repair jobs I did were like this. One house had both sides somewhat shade covered with tree canopy, but the side that faced east was way more beaten than the side that faced west which got more sun and weather blown at it. The east facing side which was shielded from weather and sun had extensive flaking and deterioration compared to the other. Also on my own house, the side that is shaded had to have 3 times more slates replaced than the other side. When moss and lichens grow and moisture sits on the slate, it seems to wear it down faster. Anyway, please correct me if this seems wrong to you. Maybe the proximity to tress and their leaves causes more delamintaion from the oils in the trees. But my barn has one side of the roof facing north with no trees around it and those slates are weak and flaky and coverd in moss while the south side looks much cleaner and in better condition. -eb | ||
| Joe Jenkins Senior Member Username: Joe Post Number: 331 Registered: 07-2006 |
Actually the north side will last longer than the south (in northern hemisphere), so if the black slates are on the north side, that may be why they still have some life in them. Otherwise, you're right, you may have to replace one side. You can use salvaged VT slates to do that. | ||
| Eric Braymer Junior Member Username: Braymer Post Number: 17 Registered: 09-2008 |
Photos of the black side would help people judge the useful life of the slates. Your guy sounds like he is at least trying to save you money. Even with delaminating, slates can last quite a while , the differing colors on each side is not uncommon. Sides that face north or are covered with trees, etc and get less sun can deteriorate faster that the other side sometimes. Comments from others should follow, but some pictures will help, especially of the side with those black slates. | ||
| Richard Pryor New member Username: Pixlaw Post Number: 1 Registered: 10-2008 |
Just bought a big Victorian (1865) house in Ohio, with a very odd roof, at least some if not most of which seems to be original to the house. The southern exposure roof is all black slate (PA black?), with some serious delaminating going on. The northern exposure has green slate, most of which seems to be in good shape. The previous owner beat the roof up pretty bad (walking on it, letting flashings/caps rust out,etc.). So some real work is needed. My roofing guy, who seems at least semi-qualified (no walking on roof, uses hook ladders, seems to use appropriate attachment techniques) claims that the delaminating slates will last a while longer and that replacement of lost/broken slates will keep the roof in good shape for the time being. Comments? And what should I do about the two different sides of the roof? If I'm reading correctly, the green will seriously outlast the black. Do I need to replace one half of my roof? Thanks for your thoughts. |
