Individual slate repair
A few broken or missing slates on an otherwise sound slope is the usual case. The broken pieces are replaced, neighboring slates are refixed, and the nails in that course are checked.
Serving Worcester County
Slate Roof Repair in Worcester: Keep the Stone, Fix the Nails and Flashing
Repair of broken slates, corroded fixings and failed flashing, with replacement reserved for slopes past the usual threshold.
- Repairs and full replacements
- Ice dams, snow load and nor’easter damage
- Slate, asphalt and flat-roof work
Get a fast quote
Fastest: call (833) 751-2102. Or send this and we call you back.
Slate Roofs
Slate Roof Repair and Replacement: what it covers
Quick answer
Slate roof repair replaces broken or missing slates and fixes the nails and flashing that hold the stone, keeping the roof where it is sound. The National Park Service recommends repair over replacement whenever possible, and a slope is replaced only when broken or sliding slates reach roughly one in five.
Slate lasts a very long time when its fixings are kept in order. The National Park Service's Preservation Brief 29 says slate should be repaired rather than replaced whenever possible, and gives 60 to 125 years for the late-1800s and early-1900s slate most often used. Most losses come from corroded nails, failed flashing and slates that slide when their nails rust through, not from the stone itself.
Worcester's older neighborhoods still carry slate that is worth repairing rather than replacing. A few broken slates are a repair, not a reason to replace a roof. The useful question is what is breaking and why, and a technician answers it by counting the slates on each slope and checking the nails and flashing.
Slate is brittle, so the first visit is usually a walk around the building and an attic check. Call (833) 751-2102 to describe what you can see from the ground.
- Service area
- Worcester & Worcester County
- Availability
- Call to reach a local roofer
- Phone
- (833) 751-2102
Warning signs
Signs you need slate roof repair and replacement
Do not walk a slate roof, even in dry weather. Slate breaks without warning, and a broken piece can slide onto someone below. Do not pick at old slates or hammer nails out from the roof. Do not spread mastic or roof cement over cracked slate, and do not pressure wash slate, which can strip the surface and loosen fixings. If a slope is sagging or slates are sliding, keep people clear of the eave and call a technician.
- Broken or split slates on a slope, sometimes with a clean crack across the stone
- A slate that has slid down and sits out of line with the courses around it
- Slate pieces on the ground beneath the eave after a wind or a heavy snow
- Rust stains running down the face of a slate from a nail head
- Nail heads rusted through, or cut nails visible from the attic
- Water staining on the ceiling below a chimney or a valley
- Chalky white powder or streaks where two different metals meet at a gutter or flashing
Options
Types and options for slate roof repair and replacement
Slope-level replacement
When roughly one slate in five on a slope has failed, the Park Service says replacing the slope is usually cheaper than individual repairs. The count and what each option leaves in place are explained before any decision.
Flashing and valley work
Chimneys, valleys and walls are where slate roofs most often leak. Flashing is rebuilt in one metal family, with heavier copper in valleys and gutters where that is the choice.
One call and it gets handled.
Most slate roof repair and replacement calls are scheduled the same day when a technician is free, and you approve the price before any work starts.
Does slate need replacing when a few slates break?
Usually not. Repairing broken or missing slates is the default, and the Park Service recommends repair over replacement whenever possible.
The threshold that matters is the count on each slope. If roughly 20 percent or more of the slates on a slope are broken, cracked, missing or sliding, the Park Service says replacing the slope is usually cheaper than individual repairs. Below that, the broken pieces are replaced and the fixings that hold the rest are checked.
Why do slates slide off?
Slates are held by nails, and when those corrode the slate can slide, crack or drop. Rusting cut nails are a common cause of slate loss.
Plain steel and galvanized nails corrode well before the slate does, and a slate hung on a rusted nail can slide down the slope or break at the nail hole. The recommended replacement is non-ferrous copper or stainless nails, set in the old positions. Roofing mastic and sealants are not a repair. They harden and make the next repair harder.
Is it safe to walk a slate roof?
No, not for a homeowner. Slate is brittle, a single step can crack a weak slate, and wet or icy slate is slippery.
Slate can look solid from the ground and crack under a boot, and a broken piece can slide and strike someone below. Ice and wet snow make it worse at the eaves and valleys, where the decking under the stone can rot slowly. Look from the ground and the attic for staining instead.
How are flashing and gutters handled on a slate roof?
One metal family is used for flashing and gutters to avoid galvanic corrosion. Copper, lead-coated copper and stainless are the usual choices.
Mixing metals at a joint lets one corrode the other, and the Park Service advises one metal type where possible, with heavier copper in gutters and valleys. Terne needs periodic painting, while terne-coated stainless does not. Failed flashing is one of the main causes of slate loss, so step flashing and counter-flashing are checked along with the slates.
What moves the price up or down here?
The number of slates to replace, whether a whole slope is involved, the condition of the nails and flashing, height and access, and any historic review. The price is explained and approved before work starts.
A few slates on a low, accessible slope is a small job, while a slope where about one slate in five has failed is a larger one. Matching stone of the same size and tone takes time to find. Replacing rusted nails across a slope takes more time than setting a few slates, and each item goes on the written scope before work starts.
Our process
How our slate roof repair and replacement visit works
Tally the slates by slope
The technician counts broken, cracked, missing and sliding slates on each slope and marks them on a sketch. The count decides whether a slope is repaired or is a candidate for replacement, and it is recorded before any slate is lifted.
Check the fixings
Nails are checked by lifting the courses where slates have moved and by looking at the nail heads from the attic. Plain steel and galvanized nails are common sources of loss, and the nail found decides what replaces it.
Check the flashing and gutters
Step flashing, valley metal and counter-flashing are checked for corrosion and lifted edges. Failed flashing is one of the main causes of slate loss, so it is repaired in the same visit.
Replace slates and fixings
Broken slates are removed carefully and replaced with matching stone where possible. Each new slate is hung on copper or stainless nails in the old nail's position. Roofing mastic is not used as a fix.
Record and plan the next check
Each slate replaced and each fixing changed is recorded with photographs. Slopes close to the replacement threshold get a suggested point for the next look.
Worcester County
Why slate roof repair and replacement is different in Central Massachusetts
Worcester's older neighborhoods still carry slate, and the city's own description of its housing says slate is worth repairing. The Park Service's guidance points the same way: the usual losses are fixings and flashing, not the stone, so a roof from that era is often repaired at the nail rather than replaced.
Four local historic districts, Massachusetts Avenue, Montvale, Crown Hill and the Elm Park Neighborhood, require a Certificate of Appropriateness for work on any visible part of a property. A Certificate of Non-Applicability covers work that changes nothing in design or outward appearance. Ask the Commission which category a repair falls into before the crew is on the roof.
Winter pushes meltwater behind slate at the eaves, where it can reach the nails and the sheathing. Insulation, air sealing and ventilation help a slate roof as much as a shingle one. The slate guide covers the repair-or-replace decision in more depth.
Where we work
Slate Roof Repair and Replacement across Worcester County
- Slate Roofs in Worcester
- Slate Roofs in Cherry Valley
- Slate Roofs in Auburn
- Slate Roofs in Shrewsbury
- Slate Roofs in Millbury
- Slate Roofs in North Grafton
- Slate Roofs in Boylston
- Slate Roofs in Leicester
- Slate Roofs in West Boylston
- Slate Roofs in Paxton
- Slate Roofs in Holden
- Slate Roofs in Grafton
- Slate Roofs in Northborough
- Slate Roofs in Oxford
- Slate Roofs in Westborough
- Slate Roofs in Spencer
- Slate Roofs in Sutton
- Slate Roofs in Rutland
- Slate Roofs in Charlton
- Slate Roofs in Upton
- Slate Roofs in Berlin
- Slate Roofs in Sterling
- Slate Roofs in Northbridge
- Slate Roofs in Clinton
- Slate Roofs in Princeton
- Slate Roofs in Webster
Not sure if you're covered? Check your ZIP code.
Related
Related services
Roof Repair
Targeted repairs to a roof that still has life left, with the checks that decide whether repair is enough.
Chimney Flashing and Repair
Repair of the metal and mortar joint where a brick chimney passes through the roof, and of the crown above it.
Roof Flashing Repair
Repair and replacement of the metal at roof joins, walls and additions, where many roof leaks start.
Historic District Roof Work
Roof repair and replacement in Worcester's local historic districts, where visible work needs review by the Worcester Historical Commission first.
Guides
Read before you book
Slate roofs in Worcester: repair the fixings before replacing the stone
Slate on a late-1800s or early-1900s Worcester roof is usually worth repairing rather than replacing.
FAQ
Slate Roof Repair and Replacement FAQs
How long does a slate roof last?
The Park Service gives 60 to 125 years for the late-1800s and early-1900s slate most often used, and says slate can last as long as 150 years. Fixings usually fail first. A technician judges a particular roof from its nails, its flashing and the count of broken slates.
Should the whole roof be replaced if a few slates break?
No. The Park Service's threshold is roughly 20 percent or more of a slope that is broken, cracked, missing or sliding. Below that, individual replacement is the usual answer, and the crew can say which slopes are close to the threshold.
Can roofing mastic hold a cracked slate?
Not as a repair. Mastic and sealants harden, crack and make later repairs harder. Replace the slate or its nail with the right fixing, and have old sealant removed first.
Why do the nails matter so much on slate?
Plain steel and galvanized nails corrode well before slate does, and rusting cut nails are a common cause of loss. Copper or stainless nails are the recommended fixings, set where the old nails were.
Do I need a permit to repair slate?
A minor repair may not need one if the building official considers it ordinary, and a larger replacement is generally permit work. A Specialty Construction Supervisor License for roof covering excludes replacing more than 25 percent of sheathing or rafters. Ask the Department of Inspectional Services about a specific address.
Is it safe to walk a slate roof?
No, not for a homeowner. Slate breaks under foot and is slippery when wet or icy. Check from the ground and the attic, and if slates are sliding, keep people clear of the eave and call a technician.