Slate roofing
Slate roof repair for older North Jersey homes
4.9 stars on Google60+ reviewsFamily-owned12 years of roofing experience
A good slate roof can outlive the people who installed it. Most slate roofs that “need replacing” really need a few dozen slates and new flashing. We repair slate the way it was meant to be repaired, so the fix lasts as long as the roof.
Why slate is different
Slate is a 100-year roof. Treat it like one.
Many of the 1900s to 1930s colonials, Tudors and Victorians in towns like Ridgewood and Glen Rock still wear their original slate. According to the National Park Service, hard slates from Vermont, New York and Virginia commonly last 125 years or more, while softer Pennsylvania slates last 60 years and up.
The stone is rarely what fails. What fails is everything around it:
- Flashing. Valleys, chimneys and walls were flashed in metal that has reached the end of its life long before the slate has.
- Nails. Old iron nails rust through and slates slide out. Roofers call it “nail sickness.”
- Foot traffic. Slate cracks when people walk on it. Painters, satellite installers and well-meaning handymen do a lot of damage.
- Bad repairs. Tar, caulk, exposed nails and metal straps all fail, and they make the next proper repair harder.
Our method
How we repair slate correctly
We follow the repair practices published by the slate roofing trade. That means:
- Matching the slate in size, thickness, color and source as closely as possible
- Removing broken slates with a slate ripper, which cuts the hidden nails without disturbing neighbors
- Fastening replacements with a copper or stainless slate hook, or a nail covered by a copper bib slipped under the course above
- No face nailing, no exposed straps, no tar or caulk on the face of the slate
- Copper flashing in valleys and around chimneys, because the metal should last as long as the stone
- Working from hook ladders and roof jacks so our weight stays off the slate
When a slate roof truly is at the end of its life, we tell you, and we go through the options with you, including synthetic slate products that give a similar look at a fraction of the weight.
Repair or replace
Can your slate roof be saved?
| What we find | What it usually means |
|---|---|
| A handful of broken, slipped or missing slates | Routine repair. Normal upkeep for any slate roof. |
| Leaks at valleys, chimneys or where roof meets wall | Flashing replacement. The slate is lifted, new copper goes in, the slate goes back. |
| Slates sliding out across many areas | Failing nails. Sections can be re-laid with new fasteners, often reusing the same slate. |
| Slate that is soft, flaking or powdery, and sounds dull when tapped | The stone itself is worn out. When around one in five slates is broken or delaminating, replacement usually makes more sense than repair. |
The one-in-five guideline comes from the National Park Service’s preservation guidance on slate roofs.
Questions
Slate roofing questions
How do I know what kind of slate I have?
Color and weathering tell most of the story. Gray-black slate that stays dark is often from Virginia or Vermont. Slate that fades to buff or brown may be a Pennsylvania type. Greens, purples and reds usually come from Vermont and New York. We identify it during the inspection so replacements match.
Can I walk on my slate roof?
No. Slate cracks under point loads, and the crack may not leak until the next freeze. Keep everyone off it, including other trades. We work from ladders hooked over the ridge.
Someone told me the whole roof has to go. Is that true?
Get a second opinion before you agree. Many roofers do not work with slate and recommend tearing it off because shingles are what they know. If the stone is still hard and rings when tapped, repairs and new flashing may give you decades more.
Do you install snow guards?
Yes. Slate is smooth, and snow lets go all at once. Snow guards hold it in place so it melts off gradually instead of landing on gutters, shrubs and walkways.
Related services
Have a slate roof? Get the right advice.
We will inspect it, photograph it and tell you what it needs.