Slate and tile are so durable that they often outlast the underlayment and fasteners.
Ribons on slate roofs.
A above the nail holes b between the nail holes and c beneath the nail holes fig.
Many of the softer black pa slate roofs are now reaching the end of the line and must be replaced they cannot be restored.
Anything above a 8 12 is preferred and slopes in the 12 12 to 18 12 range are probably ideal.
This led to the roofing contractor sorting the slate on site and installing the longest and widest slates at the.
Ribbons typically weather more and were most common in pennsylvania slate quarries.
Ribbons are visible as bands on the cleavage face of slate and represent geologic periods during which greater amounts of carbonaceous matter calcite or coarse quartz particles were present in the sediment from which the slate was formed.
So when repairing or replacing these roofs prolong the life of the installation by using heavy underlayment 30 lb.
Not only will slate shingles last longer on these steeper slopes but they will be more visible from grade and show off their natural beauty.
Ribbons of color in ribbon slates on roofs may be in the entire shingle or in some applications may be in the upper or covered portion of the slates.
The ribbon may appear in one of three places.
A good penn black slate roof may have a life expectancy of eighty years given the right roof pitch and weather exposure but the ribbons are more likely to disintegrate well in advance.
A slate roof will easily last over 100 years which is at least double of what other roofing materials can offer.
Often the ribbons are diagonal depending on how the slate was quarried.
Generally the steeper the roof the better with regard to service life of slate.
Graduated length slate roofs the practice of installing slates of varying lengths and widths on a roof came from the days when some quarries produced slate on an as available basis rather than in specified lengths and widths.
References about slate roof durability at least among home inspectors and some slate books claim that ribbon slates were inferior and likely to have a shorter life due to their mineral inclusions.
In the photo at left a mix of ribbon slates have diagonal colored stripes of mineral inclusion but they do not show the characteristic delamination and wear we see on classic ribbon slates.
Ribbon slate roofs once they start to fall apart are hopeless.
For people who do not plan to ever sell their home the incredible longevity of slate is a highly desirable benefit.
Many slate tile manufacturers offer up to 100 year warranty on their products.
A ribbon slate roof is not necessarily a bad thing as the quality of some ribbon slates is better than others.
Ribbon slate is roofing slate with linear colors running in stripes through the slate material.
Building paper or self adhering bituminous membrane copper attachers and copper flashing.
