When to Replace Slate Roof Tiles

Slate roof tiles are an attractive and very durable roofing option, known as the “100 year roofs.” In actuality, these roofs have been know to last 85 to 100 years. If your home is younger than 100 years and your slate roof has been well-maintained, it is unlikely it needs to be replaced. There are certain keys related to slate tile roofing that can help you determine whether or not you should replace your slate roof. Refer to the information below.

Missing Slate Tiles

If 20 to 30 percent of the slates tiles on your roof are missing, it is time to replace those that are left.

Delaminating Tiles

Examine your tiles for flaking or delaminating. If many of them are in this state, you should consider installing a new roof.


An appearance of powdering on the underside of your tiles is another indication that it is time to re-roof.

Sounds From Tapping

Tap on your slate tile. If you hear a dull sound—rather than a clear, solid resonance—the life of your slate roof is nearing an end.


Aged slates will become very porous like sidewalk chalk that’s been left in the rain. Then it’s time to retire your slate roof.