Dead Valley Roof Repair and Replacement in Kensington, NH — GAF Timberline Weathered Wood

What Was Causing the Leaks on This Kensington Roof?

Not every leaking roof fails because the shingles are old. On this home off South Road in Kensington, New Hampshire, years of shortcuts and poorly executed roofing details had created serious water problems in some of the most vulnerable areas of the roof.

By the time Compass Exteriors became involved, the project required considerably more than tearing off the existing shingles and installing a new roof. Three distinct conditions had to be corrected first:

• A leaking dead valley — a low-slope area where water movement slowed and previous waterproofing had failed
• An improperly terminated shingle-to-EPDM dormer transition — where the shingled ridge met the EPDM-covered dormer without a reliable seal
• Incorrectly installed roof decking — sections of plywood that provided a compromised foundation for everything above

Our job was to take the roof apart far enough to understand what had gone wrong — and then rebuild those areas correctly before the new roofing system went on. See our roof replacement services for more on how we approach complex reroofs.

Rebuilding the Dead Valley With EPDM Membrane

Dead valleys require careful planning because they collect and redirect a significant amount of water. Unlike a conventional valley with a clear path toward the eave, a dead valley can create an area where water movement slows and multiple roof planes come together. If the waterproofing and transitions aren’t detailed correctly, it becomes one of the first places a roof develops chronic leaks.

That was the situation on this Kensington property. Previous roofing work had involved shortcuts, and the resulting details weren’t providing a reliable path for water. Over time, that led to substantial leaking and deterioration around the affected roof sections.

For the dead valley repair, Compass used EPDM rubber membrane roofing to create a durable waterproof surface through the low-slope area. EPDM is commonly used in low-slope and flat-roof applications because the membrane provides continuous waterproofing in areas where conventional asphalt shingles aren’t appropriate for the slope. The membrane itself, however, is only part of the solution — the transitions between the EPDM, shingles, roof deck, walls, and adjoining roof sections all have to be properly designed and terminated. A quality membrane with poor transition details can still leak.

Correcting the Shingle-to-EPDM Dormer Transition

The existing roof had an improperly terminated transition where the shingled ridge met the EPDM-covered dormer. This is a detail that can look minor from the ground but creates significant water intrusion when it isn’t handled correctly. Water doesn’t care whether the rest of a roof looks good — it finds the weakest flashing detail, seam, or termination point in the system.

Compass removed the failed configuration and rebuilt the transition so the shingle and membrane roofing systems worked together rather than creating a vulnerable termination point. This was one of the most important corrections on the project because simply replacing the surrounding shingles would not have solved the source of the leak. This type of hybrid roof work is notably different from the Williamsburg Gray reroof we completed on another Kensington property, which was a more straightforward shingle replacement with ventilation corrections.

Replacing the Incorrectly Installed Decking

Once the roof was opened, we also found areas where the plywood decking had previously been installed incorrectly. The roof deck is the foundation for everything above it — shingles, underlayment, flashing, and membrane roofing all depend on having a properly installed, structurally sound substrate. Where the decking wasn’t right, we corrected it before proceeding with the new roof.

It is work that disappears once the new roof goes on, but it matters enormously. Installing new roofing over poorly installed or compromised decking leaves one of the underlying problems in place — the roof may look correct from the outside while a vulnerability remains underneath.

GAF Timberline HDZ® Shingles in Weathered Wood

After the failed roof details were corrected, we completed the full roof replacement using GAF Timberline HDZ® shingles in Weathered Wood.

• Dead valley rebuilt — EPDM membrane installed across the low-slope area
• Shingle-to-EPDM transition rebuilt — properly terminated at the dormer junction
• Incorrectly installed decking corrected — plywood replaced where the substrate had been improperly installed
• Full tear-off and reroof — complete new GAF Timberline HDZ® system in Weathered Wood

Weathered Wood has a blended, dimensional appearance that works well with traditional New England homes and gave this Kensington property a natural-looking finished roof. From the driveway, the new shingles are the obvious transformation. But the more meaningful improvement is underneath them — a roof where the dead valley, EPDM membrane, roof decking, and shingle-to-membrane transitions were addressed as parts of one complete system rather than a collection of patches.

Why Do Persistent Roof Leaks Keep Coming Back?

This project is a good example of why repeated roof leaks shouldn’t automatically be treated with another tube of sealant or another layer of roofing material. The Kensington home had problems created by previous workmanship shortcuts. Compass corrected those conditions before installing the new GAF Timberline roof.

A roof can have brand-new shingles and still leak if the difficult areas underneath and around them aren’t properly constructed. For homeowners in Kensington and the surrounding Seacoast area dealing with a persistent leak near a valley, dormer, or low-slope section, the entry point is almost never where the water first appears inside the home.

Roof Replacement and Dead Valley Repair in Kensington, NH

If your Kensington home has a chronic leak that prior repairs haven’t resolved, call 603-219-1523 for a free inspection. Compass Exteriors handles roof replacement, dead valley repair, EPDM and low-slope roofing, flashing corrections, and decking replacement throughout Kensington and surrounding communities.

Complex details like dead valleys and hybrid shingle-to-EPDM transitions are what separate surface-level repairs from the kind of rebuild found across Kensington roofing projects when we take on a roof with a history of failed patches.