Charlestown, RI Commercial Roofing: Torch-Down Flat Roof on a Multi-Unit Mansard Building

Like most Pinnacle projects, the work was completed efficiently — minimizing disruption for the property owner.

Pinnacle makes every project affordable with monthly financing options, including 0% interest for 18 months.

A commercial property along Charlestown‘s South County Trail carried a large mansard-style building with multiple units under one roof, and the low-slope deck crowning it had reached the end of its service life. The owner needed a flat-roof system tough enough to shrug off standing water, freeze-thaw cycles, and the coastal weather that rolls in off South County — so Pinnacle installed a heat-welded modified-bitumen roof built to protect every tenant beneath it.

Scope of Work

The crew began by clearing the low-slope deck, removing the failed roofing down to a sound substrate and inspecting the drainage paths and perimeter details along the mansard transition. Any compromised areas were addressed before a self-adhered base layer was set to lock out moisture. From there the team torch-applied the modified-bitumen plies, heat-welding each seam and rolling the laps tight so the membrane fused into a single continuous surface. Flashings were rebuilt at the walls, curbs, and the window openings that tie into the mansard face, and the finished field was checked for positive drainage so water sheds cleanly instead of ponding. You can see the full range of low-slope work on our Commercial Roofing page.

What We Installed (And Why)

The heart of this project is a multi-ply modified-bitumen system installed with heat-welded seams. On a flat or low-slope commercial roof, the seams are where most failures start, so fusing the plies together with heat — rather than relying on adhesives alone — creates a monolithic membrane with no gaps for water to work its way under. That matters on a multi-unit building, where a single leak can travel through the deck and reach more than one tenant’s ceiling before anyone notices.

Just as important was the flashing detail where the flat roof meets the vertical mansard face and the window openings set into it. Those transitions are the second most common leak point on a building like this, so the crew wrapped and sealed each one into the membrane rather than caulking over it. The result is a roof that manages water as a system: the field sheds it toward the drainage paths, and the flashings keep the walls and openings sealed against wind-driven rain.

Project Photo Gallery

Finished low-slope commercial roof membrane

Clean seam and flashing detail on the flat roof

Completed commercial roof system with proper drainage

Good To Know: Why choose modified-bitumen for a flat commercial roof?

Modified-bitumen is a proven choice for low-slope buildings because it combines multiple reinforced plies into a thick, redundant membrane. The heat-welded seams give it excellent resistance to standing water and the constant expansion and contraction that flat roofs endure through New England winters and summers. For a multi-unit building, that durability translates directly into fewer disruptions for tenants and a roof that holds up for the long haul with routine maintenance.

Why This Approach Works

A flat roof lives or dies by two things: how well its seams are joined and how well water moves off the surface. By heat-welding every lap and rebuilding the perimeter and penetration flashings into the membrane, Pinnacle removed the weak points before they could become leaks. Pairing that watertight field with verified positive drainage means rainfall and snowmelt have a clear path off the deck instead of collecting in low spots where it can eventually find its way through. It is a system designed for the realities of a busy, occupied commercial building rather than a quick patch.

Why Pinnacle

Commercial low-slope work is a specialty, not a sideline. Pinnacle is a Mule-Hide & Gaco Licensed Applicator and Firestone Building Envelope Certified, which means the crews are trained and vetted on exactly the flat-roof systems commercial buildings depend on. Serving Rhode Island since 2012, Pinnacle holds a 5.0-star Google rating with 100+ five-star Google reviews and an A+ rating with the BBB, and carries RI Commercial License #261. From the first inspection to the final drainage check, property owners get a documented, code-conscious installation from a team that stands behind it.

Charlestown, RI

Charlestown is a quiet, coastal South County town defined by its salt ponds, wide beaches, and a mix of year-round residents and seasonal properties. Buildings here take a beating from salt air and Atlantic weather, which makes a properly sealed, well-drained roof a real investment rather than a luxury. Pinnacle is proud to serve property owners across Charlestown with roofing built for the local climate.