broken slate tiles from tree falling on roof
broken slate tiles from tree falling on roof
Tree fell on this slate roof causing serious damage

Slate Roofing Inspection Guidelines

Periodic Inspection of Slate Roofs

Many slate roofs are already 100+ years old. Some of these roofs will eventually have to be replaced but others can continue to protect the home if maintained properly. In most cases, and especially on historic roofs, it is best to repair instead of replace whenever possible. A periodic inspection is the best way to determine how well you're roof is holding up. CD Kaller can identify issues such as broken, cracked, missing or weakened slates and repair these small issues before they become problems.

Listed below are guidelines on how best to inspect a slate roof.

CD Kaller is a slate roofing contractor with real appreciation for older and historic buildings and our slaters are specialists in preserving that character on your slate roof whether its a small slate repair, a complete slate roof replacement or a new installation. We can help with annual inspections and our highly skilled slaters can repair your slate roof so it retains its character and continues to protect your home for a very long time.

We are charter members of the Slate Roofing Contractors Association

Slate Inspection/Maintenance Guidelines

The National Park Service created a checklist on inspection and maintenance of your slate roof (below) and another to assist in the repair/replace decision making process.

  • Inspect the roof's overall condition annually and after severe storms.
  • For safety reasons, it is recommended that building owners and maintenance personnel carry out roof surveys from the ground using binoculars or from a cherry picker.
  • Cracked, broken, misaligned, and missing slates and the degree to which delamination has occurred should be noted, along with failed flashings (pin holes, open seams, loose and misaligned elements, etc.) and broken or clogged downspouts.
  • A roof plan or sketch and a camera can aid in recording problems and discussing them with contractors. In the attic, wood rafters and sheathing should be checked for water stains and rot. Critical areas are typically near the roof plate and at the intersection of roof planes, such as at valleys and hips.
  • Regular maintenance should include cleaning gutters at least twice during the fall and once in early spring, and replacing damaged slates promptly.
  • Every five to seven years inspections should be conducted by professionals experienced in working with slate and steep slopes. Good record keeping, in the form of a log book and the systematic filing of all bills and samples, can help in piecing together a roof's repair history and is an important part of maintenance.
  • As part of regular maintenance, an attempt should be made to keep foot traffic off the roof. If maintenance personnel, chimney sweeps, painters, or others must walk on the roof, it is recommended that ladders be hooked over the ridge and that the workmen walk on the ladders to better distribute their weight. If slates are to be walked on, it is best to wear soft soled shoes and to step on the lower middle of the exposed portion of the slate unit.

from The Repair, Replacement and Maintenance of Historic Slate Roofs - National Park Service

If you have questions about your existing slate roof or are interested in installing a new one we hope you will contact CD Kaller Inc. And please see our article on Why you should choose CD Kaller.