It was a gorgeous clear day while inspecting a Buckingham slate roof originally installed back in 1925 on a historic local church right here in Chesapeake. Natural slate is one of the most durable building materials ever crafted, and this hundred-year-old roof was still standing strong against our coastal Tidewater climate. But as Brian from The Roofing Company, Inc. team took a closer look during this Roofing for Reel inspection, he uncovered a classic hidden conflict. While the steep slate slopes were shedding water easily, an adjacent low-slope section with an internal box gutter was quietly holding standing water right against the brick chimney.

The Problem

High up on the steep roof sections, the Buckingham slate tiles were in remarkable condition, showing just how well historic slate handles our heavy coastal storms and humid air. The surprise came right along the brick masonry work, where tucked between the slate roof and the chimney was an internal box gutter lined with an EPDM rubber membrane. Instead of smoothly channeling rainwater toward the downspouts, water was pooling heavily inside the channel. Over time, standing water on a low-slope roof system can degrade synthetic rubber seams, rust copper flashings, and create subtle leaks that sneak inside interior walls long before you ever spot a stain on the ceiling during a midnight storm.

The Technical Why

To understand why this happens, it helps to look at how flat transitions and built-in gutters function together on a historic structure:

  • Internal Box Gutters: These are drainage channels built directly into the roof's framing structure rather than hanging off the exterior eaves, which keeps architectural lines clean on historic properties.
  • EPDM Rubber Membranes: A synthetic rubber roofing material used on flat or low-slope surfaces to form a seamless waterproof barrier.
  • The Pitch Requirement: Low-slope roofs aren't completely flat; they rely on a slight incline to guide water toward the drains. Decades of natural structural settling can eliminate that incline, causing "ponding water"—water that stays trapped on a roof surface instead of draining away.

In this case, the slate was doing its job, but the low-slope internal gutter had lost its proper pitch, holding water directly against the chimney's protective metal flashing (the thin sheet metal used to seal roof joints against leaks).

Professional Advice

If your property features a mix of steep slopes and flat transitions, or if you manage a local historic building with built-in gutter systems, a few proactive checks will give you complete peace of mind when coastal weather rolls in:

  • Check Low-Slope Transitions: Regularly inspect areas where steep roofs channel water down into flat sections or box gutters.
  • Keep Drains and Scuppers Clear: Leaves, pine needles, and coastal debris can easily clog small internal drains, turning a simple puddle into a major water backup.
  • Inspect the Flashing Seals: Ensure the flashings wrapped around brick chimneys remain tightly sealed, as standing water will aggressively test those seams over time.

Whenever you're ready to take a closer look at your roof's drainage, our local crew is here to help keep your property tucked away safe and dry. Give us a shout at 757-867-6600 or fill out the form on this page.