Slate Roofing, Tile and Cedar Shake in Southfield, MI

Natural slate is split stone, nailed through pre-punched holes and lapped so each slate covers the joint below it. InterNACHI gives slate 60 to 150 years. HomeGuide splits it further, with soft slate at 50 to 125 years and hard slate at 75 to 200. The stone usually outlives what holds it: steel nails rust, and old flashing wears through, so on most slate roofs the nails and metal go before the stone does. A roofer who knows slate checks the nails and flashing first before writing the whole roof off.

Synthetic slate is molded from rubber or plastic composites, with color and edges varied so it doesn't look stamped. It's far lighter than stone and cuts with ordinary tools. Lifespan estimates disagree: InterNACHI lists simulated slate at 10 to 35 years, while HomeGuide gives synthetic slate 30 to 50. Ask the contractor which product it is and what the manufacturer's own documents say. HomeGuide prices it at $9 to $12 per square foot installed.

Cedar shakes are split wood, thicker and rougher than sawn cedar shingles. They weather from tan to silver gray. InterNACHI estimates about 25 years for wood roofs. Shade, leaves and a damp north slope shorten that, because wood that stays wet grows moss and cups. Shakes need to dry out between rains. HomeGuide puts real shake at $25 to $30 per square foot installed.

Synthetic shake copies the split-wood look in composite. It doesn't rot or grow moss the way cedar does, and it doesn't need treatment. HomeGuide lists it at $12 to $20 per square foot installed. Ask to see a sample in daylight next to a real shake, because some products read as plastic up close and others are hard to tell apart at roof distance.

Clay and concrete tile can last 100 years or more, according to InterNACHI. In Southfield, clay is the riskier of the two. HomeGuide notes that clay tile suits warm climates, because cold and freeze-thaw cycles crack it, and January lows at the Detroit weather station average about 19°F. Concrete tile is cheaper ($7 to $19 per square foot installed against clay's $8 to $25, per HomeGuide) but more porous. Either one is heavy, so the rafters get checked before tile goes on a house that never had it.

A broken slate comes out with a slate ripper that cuts the old nails. The new slate slides up and hangs on a copper or stainless slate hook, or it gets nailed through the joint above with a metal bib over the nail. Matching matters more than the method. Salvaged slate of the same quarry color blends; a new slate in the wrong gray stands out for decades. Broken tiles are handled the same way, and HomeGuide lists replacing individual roof tiles at $60 to $125 per tile. Walking on slate or tile cracks it, so repair crews work from ladders, hook ladders or roof jacks.