Preserving a Historic Cade Allen Residence

Local landmark property gets a new metal roof and sets precedent for historic preservation

Cade Allen, an early 20^th-century developer and homebuilder, left a lasting mark on St. Petersburg, Florida, specifically the historic Allendale neighborhood, with his distinctive architectural style and commitment to quality workmanship. His works are typically characterized by meticulous exterior stonework (he started as a mason and carpenter) and Mediterranean and Spanish Revival-inspired design elements, like vaulted wood-beam ceilings and arch-top windows and doors.

One of his earliest projects, the Foster Grove House, is one of several Cade Allen residences in St. Pete that meet the strict local standards to be designated as a historic landmark. In fact, it was the very first home that Allen occupied with his own family. It came with the purchase of a sprawling 160-acre citrus grove, which Allen purchased from the Foster family in 1923. Allen and his sons would spend the next 30+ years building 40 houses on the citrus grove property and surrounding area to create what we now know as the Allendale neighborhood. Because of its historical significance, the Foster Grove House required careful preservation and oversight during a summer 2025 renovation project.

Further, this re-roofing project represents a turning point for how historic homes in hurricane-prone regions can be preserved. “As far as I know, this is the first designated historic home in Florida that has received approval to have asphalt shingles replaced with metal roofing,” said Jeremy Wood, General Manager at GMR Metal Roofs. GMR installed the house’s new metal roof, which was fabricated by Innovative Sheet Metals, a Drexel Metals Plus Member, using Drexel Metals’ coil. “It sets a precedent for future projects, showing that we can protect historic structures better with a metal roof without sacrificing their character.”

Breaking preservation barriers

Homes designated as historic landmarks typically require replacement building materials to be of “like kind and quality” to the original material used. So, for the re-roof on the Foster Grove House, St. Pete’s Urban Planning and Historic Preservation division expected the homeowners to use asphalt shingles, the roofing material that was in place when the home received its historic designation. However, what met preservation guidelines fell short of meeting the homeowners’ real-world needs.

After all, this home is located in St. Pete’s hurricane evacuation zone. Homeowners Greg Tappan and Keith Weiler needed a roofing material capable of withstanding Florida’s extremely tough coastal weather, including hurricane-level winds and wind-driven rain. Asphalt shingles, with their limited durability and short service life, would not provide the protection or longevity they were looking for. “Mr. Tappan did not want their roof blowing off in the next hurricane,” explained Wood. “They want to protect their home with the best roofing option, get it done once, and not have to worry about re-roofing again.”

With these needs in mind, Tappan approached GMR Metal Roofs about installing a standing seam metal roofing system. Together, Tappan and Wood put a re-roofing request in front of St. Pete’s Urban Planning and Historic Preservation division, but the commission initially rejected it, adhering to strict historical guidelines.

Undeterred, Tappan and Wood reappealed to St. Pete’s Community Planning and Preservation Commission, a group of non-compensated community members appointed by the mayor. This board holds the final authority on historic preservation decisions. After carefully reviewing the arguments laid out by Tappan and Wood, the board approved the use of metal roofing for the project by majority vote – a landmark decision.

The argument against asphalt shingles

In their presentation to the board, Tappan and GMR Metal Roofs largely emphasized two critical factors: long-term performance of the roofing material and financial sustainability. In a state where hurricanes are a constant threat, these factors are inseparable.

Case in point, Hurricane Ian, the costliest storm in Florida’s history, caused an estimated $112 billion in damage. Data collected by the Insurance Institute for Business and Home Safety (IBHS) underscores the vulnerability of traditional roofing materials: one out of every two asphalt shingle roofs inspected had visible damage. A similar Federal Emergency Management Agency (FEMA) analysis found that 90 percent of asphalt shingle roofs older than seven years sustained visible damage, compared to just 21 percent of metal panel roofs.

For homeowners like Tappan living in hurricane-prone St. Pete, the choice of roofing material makes a significant difference. “Asphalt shingles have no real wind resistance and that made it nearly impossible for the homeowner to secure insurance coverage on his historic home,” Wood explained. In general, asphalt roofs are only insurable for 10 to 12 years. Even if coverage were obtained, Tappan would have faced the burden of replacing his roof every decade. He told the board that this costly and unsustainable cycle would force him to sell his home.

Metal roofing delivers tested performance and insurability

A standing seam metal roof offered Tappan a smarter path forward for homeownership. “With metal roofing, you can get insurance coverage for 25 to 30 years, reduce premiums and actually protect the historical home long-term,” Wood said.

Capitalizing on this advantage, GMR Metal Roofs installed a DMC 450SL profile in a Drexlume finish, delivering a roof that preserved the home’s historic integrity while ensuring it is equipped to face any future storms. Most notably, the standing seam system is engineered to resist winds up to 120 miles per hour. The presentation to the board also highlighted that with added adhesion of a polymer sealant, the metal roof can achieve higher wind speed resistance.

Additionally, the system is certified to wind-resistance testing standards such as: UL 580 Wind Uplift, TAS 125 Wind Uplift, UL 1897 Extended Phase Wind Uplift, ASTM E1592 Uniform Static Pressure Uplift, and ASTM E1680 Air Infiltration. It is also certified to the highest impact resistance class, according to UL 2218 impact rating standards, offering unmatched protection against any windborne debris.

Unlike asphalt shingles, panelized metal roofing systems extend from eave to ridge and interlock with adjacent panels to minimize the points where gusts of wind can lift and damage the roof. Metal panels also have a substantial strength-to-weight ratio. This means individual panels can withstand direct wind without increasing the overall weight of a roof. 

The financial advantage of a metal roof is also compelling. “Before a metal roof, the homeowners’ insurance policy was $10,000 a year. Now, it has dropped to around $7,000. That’s $3,000 in annual savings,” Wood noted. “So basically, the metal roofing will pay for itself in a few years.”

Warranty coverage that actually protects

Warranty was another issue the homeowner and GMR Metal Roofs highlighted in their presentation to the board. Even if Tappan managed to secure insurance for an asphalt shingle roof and absorb the cost of re-roofing every decade, the warranties attached to the system offer little meaningful protection. “Shingle warranties are prorated. Most of them only cover material cost,” Wood explained. In other words, the longer the roof has been in service, the less coverage the homeowner actually receives. By the time damage occurs, the warranty’s value may be largely depleted.

The limitations don’t stop there. Wood flagged that nearly all asphalt shingle warranties contain an “Act of God” clause, which excludes coverage for storm- or fire-related damage. “So, if your roof blows off in a storm, you’re on your own,” Wood said. For homeowners in hurricane evacuation zones like St. Pete, that exclusion undermines the very protection they need most.

Metal roofing systems, on the other hand, come with warranties that reflect the durability of the product itself. Drexel Metals backs its standing seam systems with a 25-year non-prorated warranty, meaning the coverage does not diminish over time. More importantly, there are no exclusion clauses. “That’s why I use Drexel Metals,” said Wood. “The panels are American-made, the warranty is clear, and they actually honor it.”

Built for longevity and durability

In addition to wind events, St. Pete homes are also vulnerable to flooding and heavy rainfall. But metal roofing’s resilience is supported through extensive testing. The standing seam metal roof installed over the Foster Grove House is certified to ASTM E1646 Water Infiltration standards and can achieve the TAS 100 Wind-Driven Rain designation. This testing standard establishes resistance to wind-driven rain by spraying water on the metal roof panels at a rate of 8.8 in/hr. while a machine generates wind speeds up to 110 mph. Metal roof panels that pass this test will not exhibit any water infiltration through the deck sheathing. Further, a metal roof’s weathertight performance can be enhanced with a proper underlayment and an advanced coating or paint finish. “Longevity-wise, a metal roof means less maintenance and fewer associated costs,” Wood noted. “We can preserve these historic homes a lot better with metal than we ever could with asphalt.”

Preserving history, protecting the future

The re-roof of the Foster Grove House sets a precedent for historic preservations. By securing approval to use metal roofing (versus asphalt shingles) on a structure designated as a historic landmark, Tappan and GMR Metal Roofs opened doors for others to follow.

For Wood, it was the culmination of decades of advocacy. “I’ve been in this industry 24 years and finally convinced a historic preservation committee to let me protect a historic home with a superior product,” he reflected. “Installing the roof was the easy part, we do that every day. The real victory was proving that metal roofing is not only compatible with historic preservation, but the best way to ensure these homes endure for the next century.”

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