Can an old slate roof be repaired, or must it be replaced?
Often it can be repaired. Slate itself can last a very long time. What usually fails first is the fasteners, the flashing and the underlayment. If the slates are sound, a roofer can replace the failed parts and keep the roof, and that is typically the better option on a historic house.
The test is the stone. A slate that rings when tapped and does not flake is still good. Slate that is soft, delaminating or crumbling is near the end.
Ask the roofer to explain what they found, with photographs, and to price a repair and a replacement separately.
Why do cedar roofs wear faster under trees?
Cedar needs to dry between rains. Shade, leaf litter and moisture keep it damp, which encourages moss and rot, and repeated freezing splits the wood. A cedar roof under heavy tree cover shows wear on the shaded slopes long before the sunny ones.
Keeping the roof clear of debris and the gutters flowing helps. Trimming limbs where safe lets sun in.
Moss should be addressed by a roofer, since scrubbing or pressure washing can damage shakes.
Why choose a specialist for slate and cedar?
Because the work is unlike shingle roofing. Slates can crack under a boot, nails must be the right type and metals must be compatible. A roofer without experience can break more than they fix. Ask how many slate or cedar roofs the roofer works on, and ask for photographs of earlier work.
You can also ask what tools are used for lifting slates and what fasteners are specified. A confident answer is a good sign.
The line connects you with an independent roofer who serves your town. Say at the start that the roof is slate or cedar.
Do historic homes have special rules?
Some do. If the house is in a local historic district or has a recorded designation, the town may have a say in materials. The rules vary and this site does not state them, so ask the town building office or historic commission before changing the roof's appearance.
Repairs that keep the same material are usually simpler than a change of material. The roofer should confirm what the town requires before work begins.
How do snow and ice affect slate and cedar roofs?
Snow sliding off slate can break pieces below and tear gutters, and ice at the eaves can lift slate or split cedar. Snow guards hold snow in place on slate, and good attic insulation and ventilation reduce ice. Both roofs need clear gutters and valleys, so meltwater leaves the roof.
Heavy snow loads sit on old rafters, so sound framing matters as much as the covering. A roofer who knows these roofs looks at the attic as well as the slope.
Snow guards on slate are placed to break the fall into small pieces, and they are chosen to suit the roof. On cedar, the main risk is moisture, so ventilation under the shakes matters.
