Roof Replacement in Blackstone, MA: Leaking Skylights, Competing Vents, and a Ridge That Was Never Opened

Overview

In June 2026, a homeowner contacted Master Roof about water appearing inside their house and asked us to price a roof replacement in Blackstone, MA. The home was built in 1986, which meant the roof had been working for roughly forty years — well past the point where an asphalt roof owes you anything. Our inspector spent the afternoon on the roof and in the attic and came away with nearly forty photos, because this roof had more than one thing going wrong at once.

The shingles were finished. But the leaks were not coming from the shingles alone — they were coming from aging skylights, and the attic underneath was quietly telling a second story about ventilation. Both had to be solved together, or the new roof would inherit the same problems.

What the Inspection Found

Shingles at the end of their service life

Across every elevation, the shingles were dry and brittle. Granules were washing off, edges were curling, and whole courses were lifting where the factory adhesive strip had given up. Once that seal releases, wind gets underneath the shingle and the roof stops working as a system. Roofs of this vintage were commonly built with three-tab shingles, which have a shorter service life than the architectural shingles used today.

Skylights that were leaking, not just old

Two skylights showed staining on the surrounding ceiling and drywall — the clearest confirmation of an active leak we found. Skylights have roughly the same service life as the roof around them, which is why we recommend skylight replacement at the same time as the roof. Re-flashing an old skylight means breaking factory seals that were never designed to be opened and closed again, and those seals are the part doing the waterproofing.

We took the same approach on a 1950 home in Uxbridge, where skylight replacement was folded into the roof project rather than deferred.

A ridge that was cut open but never vented

In the attic we found the ridge board opening cut, as though a ridge vent had been planned — but no ridge vent was ever installed above it. Instead, the house had picked up a collection of different ventilation systems across four decades: gable vents at both ends, soffit vents along the eaves, and a power vent over the garage.

That combination sounds like more airflow. It is actually less. When systems are mixed, air short-circuits — the exhaust pulls from the nearest opening instead of drawing across the whole attic, and large sections get no air movement at all. The fix for attic ventilation problems is to commit to one balanced system, not to add another vent.

Moisture the attic had already recorded

Sections of the roof decking showed dark staining — the signature of condensation forming against a cold deck in an under-ventilated attic. Left alone, that pattern leads to mold and eventually to soft decking. Insulation was also thin in several bays, which makes the condensation problem worse. We found a similar pattern on a proactive replacement in Milford, where hidden attic moisture was the real story.

The good news: the 1986 plywood decking was still dry and structurally sound in most areas, which meant the deck could be reused rather than replaced.

The Ventilation Standard We Design To

Attic ventilation follows the 1/300 rule: for every 300 square feet of attic floor, the roof needs at least 1 square foot of net free ventilation, split evenly between intake at the eaves and exhaust at the ridge. Exhaust should never exceed intake — an exhaust-heavy attic pulls conditioned air up out of the living space instead of pulling outside air through the attic.

Roughly 80% of older homes we inspect have a ventilation problem of some kind. It is the single most common thing a new roof gets installed over without being corrected. A Mendon project and a 1968 Holliston home both turned on the same issue.

The Work Performed

• Full tear-off of the existing shingles down to the deck, with the plywood inspected and confirmed sound before anything went back on.
• The ridge properly opened and a continuous ridge vent installed, paired with the existing soffit intake to create one balanced system.
• Both aging skylights replaced rather than re-flashed, preserving factory seals on new units.
• New leak barrier at the eaves, valleys, and all penetrations, followed by synthetic underlayment across the full deck.
• Pipe boots replaced with heavy-duty boots rated to last the life of the roof, rather than standard rubber boots that fail early.
• Chimney flashing rebuilt in three layers: ice and water membrane carried six inches up the brick, aluminum step flashing woven into every shingle course with lead at the corners, and new counter-flashing over the top.
• Gutters cleared and checked — the leaf guards were clogged in several runs, which pushes water behind the gutter and rots the fascia.
• GAF architectural shingles installed across the entire roof.

The Result

The home now has a complete roofing system rather than a collection of parts. New skylights sit in new flashing, the ridge finally exhausts the air the soffits bring in, and the chimney has three independent layers of protection where it meets the roof plane.

Just as importantly, the attic conditions that were staining the decking have been addressed. A roof that breathes properly stays dry underneath, and a dry deck is what makes a shingle warranty mean something.

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