Selecting a historically appropriate roofing material is often restrictive as a simple matter of economy. Not everyone can afford a new slate roof. But individually landmarked structures and those in local historic districts are often monitored by historic district commissions (HDCs) that typically require property owners to replace in-kind or with an otherwise historically appropriate material.
Although the preference is replacement in-kind, an intelligent argument for an alternative can often be made. The HDC can consider other materials that were available at the time of construction, as well as what buildings of similar style in the community have on their roofs. A Queen Anne may have started with a polychromatic Vermont slate roof, but the commission can consider that nearby Queen Annes have monochromatic Monson slate or even cedar shingles. A Greek Revival may have a silver-coated tin roof, but few would argue with a homeowner willing to replace it with standing-seam copper. Let’s look at several American building styles and the materials used to roof them.
Colonial Styles, 1620 to 1780
From the New England Salt Box to the Dutch-vernacular homes of upstate New York, the earliest structures in the American colonies were roofed with wood shingles. It is a myth they were covered with hand-split shakes because these sometimes do not hold up well. Wood shingles were easily made by planing down the shakes to a uniform thickness for ease of installation.
In the Northeast, Eastern white cedar was the typical material used while cypress was often used in the South. Western red cedar was not used much in the eastern U.S. until after the 1850s and should not be considered appropriate on a circa-1820, Federal-style structure in Connecticut. Eastern white cedar, however, rarely lasts longer than 10 years in a roofing application. Instead, preservation architects now specify Alaskan yellow cedar. Predominantly distributed from British Columbia, this dense wood is favored because of its longevity and because it develops a silvery patina, like Eastern white cedar, within one year.
Federal and Neoclassical Styles, 1780 to 1820
Many of these buildings have low-slope roofs and are often obstructed by a balustrade that runs across the top of the eaves. In congested, urban environments, the roof may not even be visible from the street. This raises the obvious question: What needs to be done when an element of the exterior is not within the street view? Most HDCs use that standard question to limit their purview over a proposed alteration. If your roof falls into this category, then you should pick the most enduring and sustainable material you can afford.
These structures were not often originally covered in slate, though many are today. Original roofs were wooden shingles—less than ideal on a roof with a shallow pitch. In limited instances, standing-seam or flat-lock-seamed roofs are seen on these building styles. To find out what’s appropriate, check out roofs on structures of the same style in your neighborhood and neighboring communities.
Greek Revival, 1820-50
This style also features a low-slope roof, typically 4:12. Although the original roof material may have been wooden shingles, many of these roofs in the Northeast were replaced by a more sustainable material long ago. Flat-lock tin or terne-coated steel were typical from the late 1800s on. Because many of these structures also have box gutters at the eaves, keep in mind that relining these systems is costly and will need to tie in to the new roof material. (See “Traditional Gutter Systems in North America”, March/April issue, page 56, or bit.ly/1Mw7Qek.) It is not uncommon for an affordable membrane, like EPDM or TPO, to be used on the majority of the roof while a costlier appropriate material, like copper, covers the visible, projecting “porch” roof.
PHOTOS: Ward Hamilton
The National Roofing Contractors Association (NRCA) has released its 2014-15 market survey providing information about overall sales volume trends in the roofing industry, roofing experiences, material usage and regional breakdowns. It is an important tool to measure the scope of the U.S. roofing industry, and the data provides a glimpse into which roof systems are trending in the low- and steep-slope roofing markets.
This year’s survey reports sales volumes for 2014 and 2015 projections averaged between $7 million and just more than $8 million, respectively, and revealed a near-steady ratio of low- to steep-slope sales of 72 percent to 28 percent.
For low-slope roofs, TPO remains the market leader with a 31 percent share of the new construction market and 26 percent of the reroofing market for 2014. Asphalt shingles continue to dominate the steep-slope roofing market with a 44 percent market share for new construction and a 58 percent share for reroofing.
Polyisocyanurate insulation continues to lead its sector of the market with 75 percent of new construction and 70 percent of reroofing work.
In addition, roof cover board installation for 2014 was reported as 24 percent in new construction, 46 percent in reroofing tear-offs and 30 percent in re-cover projects.
NRCA’s market survey enables roofing contractors to compare their material usage with contractors in other regions, and provides manufacturers and distributors with data to analyze, which can affect future business decisions.
The Roof Coatings Manufacturers Association (RCMA) has launched its Speakers Bureau program to offer an educational presentation on reflective roof coatings. RCMA’s Speakers Bureau consists of several RCMA members with expertise on the topic who have volunteered to deliver presentations throughout the country.
This presentation, titled “Reflective Roof Coatings: Cool Stories,” is approximately one hour in length, and discusses the key benefits and the environmental importance of reflective roof coatings used on low-slope roof systems. The science behind reflective roof coatings is presented in an easy-to-understand format and real-world case studies are presented to illustrate the information presented. The presentation content is intended to enable attendees to:
- Understand the benefits that reflective roof coatings impart on low-slope roof systems.
- Recognize why reflective roofs are environmentally important and comprehend the science behind how reflective roofs save energy.
- Determine best practices for preparing a roof membrane and application methods for reflective roof coatings on low-slope roof systems.
- Identify payback, energy savings, and other non-quantifiable benefits by evaluating several real-world roof-reflectivity case studies.
RCMA is an approved continuing education provider with the American Institute of Architects (AIA) and RCI Inc. By attending the course, attendees qualify to earn 1 AIA General Learning Unit Hour (1 LU Hour) as part of AIA’s Continuing Education System or 1 RCI Continuing Education Hour (CEH).
Groups interested in offering this presentation at an upcoming meeting or event should contact RCMA Staff Associate Cecily Alfonsi to participate.
Building products distributor ABC Supply Co. Inc. has opened additional branches on opposite sides of the country—one in Cumberland, Md. and the other in Sacramento, Calif.
The Cumberland location serves contractors in the western Maryland and south central Pennsylvania markets where ABC Supply has not previously had a presence. The branch in Sacramento is the second in the area and provides contractors working on the south side of the city a convenient alternative to the company’s store in Roseville, north of the city. Both stores carry steep- and low-slope roofing materials, accessories and related roofing supplies, along with other exterior building products appropriate to each market.
Three branches of building products distributor ABC Supply Co. Inc. have moved into facilities that will enable them to better serve local contractors and builders.
The Bloomington, Ind. store moved to 1600 N. Curry Pike. The East Peoria, Ill. branch relocated to 399 Truck Haven Road. The Oklahoma City facility is now at 1500 W. Reno Avenue. All three locations carry steep-slope and low-slope roofing products and systems, siding, windows and doors, and related supplies. Other product offerings are determined by local market conditions.
ABC Supply is a wholesale distributor of roofing, siding, windows and other exterior building products. Since its founding by Ken and Diane Hendricks in 1982, ABC Supply’s focus has been serving professional contractors and offering the products, services and support they need to build their businesses.