Regular maintenance will help preserve a slate roof’s durability and its weather resistance. The first step is an annual inspection by a qualified slate roofing professional. The inspection should include a thorough check of the drip edges, valleys, ridges, flashing, vents, and chimneys for damage, wear, and instability, and should note any broken, damaged, or missing slates. Flashing, nails, and other components do wear out and will require replacement, but generally, a slate roof does not need to be replaced if the slates are in good condition.
Slate and snow—a slippery slope
Unlike shingle roofs, the surface of a slate roof is fairly smooth. Large sheets of snow may slide off the roof as the surface below heats up, which can be either a minor nuisance or a potentially dangerous situation, depending on where the snow falls. The solution is to install snowguards that are designed to hold the snow on the roof, where it can melt and drip safely.
A few more facts about slate
Natural cleavage allows slate to be split in one direction, with the length running in the direction of the grain. Depending on the rock from which it was quarried, some slate splits to a smooth, fairly even surface texture, while other slate is rough and uneven.Chemical and mineral composition determines slate’s color. Slate whose color changes minimally from exposure to weather is known as permanent or unfading slate. Slate that shows a more noticeable color change is known as weathering slate.