Opinions about the percentage will vary by roof size type and type of slates installed but for north american slate roofs using american or canadian slates if more than about 25 of the slates on an existing roof need replacement because of the labor cost of working carefully to remove and replace individual areas of bad slate at that percentage it becomes more economical to replace the entire roof with new slate.
Slate roof lifespan.
60 to 90 years.
These life expectancies are general experience with the material and do not consider installation or environmental factors which vary from one building to the next.
For people who do not plan to ever sell their home the incredible longevity of slate is a highly desirable benefit.
As such slate will outlast multiple generations of occupants at a given address.
S1 rated roofing slate is warrantied to last 100 years but it s expected to last even longer.
Typical life for pennsylvania slate roofs is 40 50 years.
Bur roofs typically last from 20 to 30 years.
In most environments slate shingles will last at least 125 years and sometimes as long as 200 years.
100 to 200 years.
Slate from different mines has different average slate roof life expectancies with proper installation and regular maintenance.
Other factors in roof longevity.
125 to 175 years.
Installation costs and lifetime value built up roofing average about 4 per square foot installed.
175 years or more.
Pennsylvania or ribbon slates.
A slate tile roof can last a century or longer.
Natural slate roofing that meets the s1 grade through direct independent testing by the national slate association is the highest grade slate possible and will have the longest lifespan of nearly any roofing material available.
Life expectancy of ribbon slates.
Clay tile typically lasts 40 to 60 years while slate and concrete tiles have a lifespan of 50 to 100 years.
A slate roof will easily last over 100 years which is at least double of what other roofing materials can offer.
For fibre cement roof slates the life expectancy is a little shorter at around 50 60 years.
Maximizing the lifespan of a built up roof is accomplished by regular inspection and repair and by keeping debris off the roof to prevent degradation of the surface.
Many slate tile manufacturers offer up to 100 year warranty on their products.
Siga 24 slate roof.
This can vary depending on the manufacturer.
Durability and low maintenance.
Slate is one of the few roofing options that doesn t need to be replaced within the span of a lifetime.
Slate a natural metamorphic stone with a fine grain appearance is perfect for being cut into uniform roofing tiles.