Slate which is a type of stone is used for the roof tiles instead of shingles. It splits in thin sheets and is nailed to the roof the same as regular asphalt shingles.
Slate can last for a hundred years tiles less than half that.
too many variables here, mostly the size of the roof above it (steepness, weight of shingles, tile or slate? etc. You're best to overengineer it. A double thickness (3.5" X 12" or 16" wide) glulam will support a reasonably large roof above it, otherwise a simple double 2x12 would work for a 3/12 -6/12 pitch roof with light grade 30 year shingles.
a gable roof is double pitched with vertical ends
From AS 1684.4 Residential Timber Framing Code 2.6.4.1 Coupled roof Pitched roof construction with a roof slope not less than 10°, with ceiling joists and collar ties fixed to opposing common rafter pairs and a ridgeboard at the apex of the roof (see Figure 7.1). A coupled roof system may include some area where it is not possible to fix ceiling joists or collar ties to all rafters, e.g., hip ends or parts of T- or L-shaped house. 2.6.4.2 Non-coupled roof A pitched roof that is not a coupled roof and includes cathedral roofs and roofs constructed using ridge and intermediate beams.
The minimum covering of reinforcement for roof slab is 30mm
Yes
Maintaining a slate roof is very important to avoid your roof from getting damaged. To maintain the natural slate roofing can be beautiful, it can be extremely heavy and expensive. CertainTeed manufactures various roofing shingles to replicate the look of natural slate roofing.
Slate rock is normally used for roof tiles etc.
It would depend on the type of roof. Do you have a slate roof or a shingled roof? In the Pittsburgh area i would recommend Rick John Roofing. Not sure if they work on slate, but they do work on shingled roofs.
Slate can last for a hundred years tiles less than half that.
Lead flashing.
slate
No. Slate is used as a roofing tile.
slate on a roof is a compound. because slate all around is a compuond since it is only made up of two mixtures.
Yes, plenty of people use slate tiles as a roof. However, they are designated to be used for the roof and not anything else.
yes depending on how much you use
Generally, stainless steel or copper nails are used to fasten slate shingles to the roof sheathing.