Cracked broken loose or missing slates should be replaced as soon as possible by a roofer experienced in slate work.
How often should a slate roof be replaced.
This is not the case.
Two major signs of imminent roofing replacement are powdering on the underside and major delamination or flaking.
Dont know if that helps any but im sure a roofer will be along shortly.
Installed properly slate roofs require relatively little maintenance and will last 60 to 125 years or longer depending on the type of slate employed roof configuration and the geographical location of the property.
Consequently you will end up spending at least double the amount and probably more than it would have cost you to initially install a metal roof.
There are a number of factors that will extend or limit the lifespan of a slate roof.
This means that you will be replacing this roof 2 4 times over the same 40 60 year period.
The suburban skyline roof.
By contrast when you put up asphalt shingles you can expect them to last 12 20 years at best.
However as with all building materials they will eventually begin to degrade.
A slate roof can generally last at least 80 to 100 years with many lasting much more than that.
Slate roofs like all roofs should be inspected annually.
The rule of thumb among slaters is to push for replacement once 20 30 of the slate has deteriorated beyond reasonable repair.
If more than 10 percent of the total surface of the roof is damaged a.
Replacement on the other hand needs to take place at some point in the life of all slate roofs particularly those on older historical houses.
For instance a typical asphalt shingle roof lasts 20 to 25 years while a roof installed over an existing layer of shingles should be replaced after 20 years.
Roofer i do some work with says as a guide usually 50 of the origional slate can be reused and the rest would need to be new.
You need to know what to look for to judge if the time is right for a roof replacement.
Some slates have been known to last over 200 years.
After 45 75 years slate roofing is rarely subject to an entire roof replacement.
The type of slate the quality of the slate roof pitch and weather conditions are some factors that can affect how long a slate roof will last.
Replacing a slate roof.
Because slate is often called a 100 year roof homeowners sometimes assume that it doesn t need maintenance for a century.
If damaged tiles are found all over the roof the tiles are probably too old to salvage and it s time to replace the roof.