Slate and Cedar Roofs on Older Montgomery County Homes: Repair, Match, or Replace

Drive through some of the older sections of Abington, Jenkintown, or Ardsley and you'll still see slate roofs that have been up there since before most of the houses around them were built. Cedar shows up almost as often, especially on homes from an era where it was the standard choice rather than an upgrade. Both materials age in their own way, and neither one behaves like the asphalt shingle roofs most people are used to.

Why slate lasts, and what actually fails on it

A real slate roof, individual stone tiles, can genuinely outlast the house it's on. What fails first usually isn't the slate itself, it's the fasteners holding it down or the flashing around chimneys and valleys. Slate nails corrode over decades, and once a nail fails a tile can slip or slide even though the stone itself is perfectly sound. That's why a slate roof with a handful of slipped or missing tiles is very often a repair, not a full replacement, as long as someone experienced with slate is doing the work. Walking a slate roof incorrectly, or using the wrong fastener on a repair, can do more damage than the original problem.

Copper flashing was common on homes built when slate and cedar were standard, and copper ages differently than the aluminum or galvanized steel flashing used on most roofs today. A slate roof with original copper flashing that's finally failing after decades is a different repair than one where the flashing was already replaced with a shorter lived material at some point. Knowing which one you have changes what the repair actually needs to include.

What ages a cedar roof

Cedar shingles and shakes age differently depending on how much sun and moisture a given slope gets. A south facing slope can wear faster than a shaded north slope on the same house, which is why cedar roofs often need attention in sections rather than all at once. Moss and algae growth, curling shingles, and shingles that have gone thin and brittle are the signs to watch for. Cedar that's simply weathered to grey is not automatically a problem, that's the material aging normally. Cedar that's cracked, cupped, or soft when you press on it is a different story.

Matching an old roof without making it worse

The hardest part of repairing an older slate or cedar roof usually isn't the labor, it's finding material that actually matches what's already up there. Slate comes in different thicknesses, textures, and colors depending on the quarry it came from, and a mismatched patch stands out for decades on a roof that otherwise looks original. Cedar has the same issue in a smaller way, new cedar is a different color than thirty year old weathered cedar until it ages in. On both materials, sourcing salvaged or closely matched stock, and knowing where on the roof a slightly off match will be least visible, is most of the skill in a good repair.

On a cedar roof, the type of cedar used matters too, shakes are thicker and rougher split than shingles, and mixing the two on the same roof, even to save money on a repair, changes both how the roof looks and how it sheds water. A good repair matches not just the color but the cut.

When it's time to talk about replacement

• Fastener failure across a wide area rather than a handful of isolated tiles or shingles
• A roof deck underneath that's showing soft spots once a few tiles or shingles are pulled back
• Damage concentrated at valleys and flashing points across multiple areas of the roof
• Material so far past matching that patch repairs would look worse than a full re-roof
• Ongoing leaks that keep returning to the same area despite repeated repairs

None of this is a decision to make from the ground with binoculars. The only real way to know which category a given roof falls into is to get up there and look at the tiles or shingles, the fasteners, and the deck underneath directly.

Get someone who works on these roofs regularly

Slate and cedar aren't asphalt, and a repair that's routine on one is a specialty job on the other. We've been working on roofs across Montgomery and Bucks County for more than thirty years, including the older slate and cedar homes in Abington, Jenkintown, Ardsley, and Cheltenham. We do free inspections, so you can find out what you're actually looking at before deciding between a repair and a replacement. Call (267) 688-3163.