20-30 Minute Assessment

Slate Roof

A well-maintained slate roof can last centuries. Slate resists water and fire, and it does well in any climate. Heavier than most roofing materials, it needs a strong frame.

While slate is durable, it can grow brittle (delaminate) over time. If fasteners fail, the slates can shift and leave you open to water damage.


Annually and after storms

Repair and replacement costs

Typical Costs

  • Repair: $700 – $2,500
  • Replace: $10,000 – $30,000

Life span


100+ years

Steps to Assessing Your Slate Roof


Step 1: Look for any cracked, displaced, or missing slates. Pay attention to the valleys where different planes of your roof meet. Slates in these areas often move, and gaps could allow water into your home.


Step 2: Some discoloration is normal, but chalky or white patches may indicate water damage and aging. If you see these issues, get a professional inspection.


Step 3: Inspect the flashing. You’ll see it where the roof meets things like chimneys, vents, and skylights. Look for corrosion, holes, cracks, missing sealant, and gaps. These issues should be addressed immediately.


Step 4: Bad repairs to slate roofs are common. If your roof looks good, but you’re still experiencing leaking, it may have been repaired improperly.


Step 5: Remove anything growing on your roof. Moss, lichen, mold, and vines can damage it.


Step 6: Inside your home, check for cracked drywall, windows or doors that don’t open or close smoothly, and cracked, bent, or bowed rafters in your attic. These issues could suggest a structural problem connected to the weight of your roof. Bring in a professional to take a look.