Designing for Durability
Design: Toward a Durable Wood Building Envelope
Although wood structural systems are capable of meeting service life objectives, there are potential threats to longevity that must be considered, as there are with any material. Moisture is one of the most challenging, and no material is immune. Good design ensures that wood materials can last and weather well in various climates, including those with high humidity, frequent sun, and heavy rain. With proper detailing to prevent bulk water intrusion and moisture entrapment – i.e, to avoid excessive wetting and promote drying – these issues can be avoided.
For wood, an additional consideration is protection against insects. In some parts of the country where termites pose a significant problem, building codes require the use of preservative-treated wood or wood species that are naturally insect resistant.
Regardless of material, long-term durability starts with good design—including proper detailing, product selection, and quality control.
BUTLER BROTHERS BUILDING: 1906 Timber Building Stands the Test of Time
Building exterior: Butler Square
Building interior: Preservation Alliance of Minnesota
In 1900, T. B. Walker (who eventually founded the Walker Art Center) bought the 1.4-acre “baseball block” in Minneapolis, Minnesota, and with partner Levi Butler, decided to use the site for a nine-story warehouse building.
In 1906, construction began on the Butler Brothers Building, a 500,000-square-foot warehouse for the Butler Brothers Company, a mail order retailing firm. It was designed by architect Harry W. Jones at a time when American architecture was shifting toward more structural simplicity. Its thick masonry bearing walls, cut by vertical recessed windows and topped by corbelled parapets, gave it a fortress-like appearance. Heavy timber post and beam construction provided for the warehouse’s 300-pound-per-square-foot loading requirement. The Douglas fir timbers were sawn at Walker’s own lumber mill in Aitken, Minnesota, precut and put together on a module measuring approximately 14 feet by 16 feet. The columns receive the beams with cast iron brackets, and gradually diminish in size from 24 inches square on the ground floor to 9 inches on the ninth floor.
In 1974, the successful rebirth of Butler Square as a mixed-use retail/office building served as a catalyst for the surrounding area and was responsible for much of the restoration that has taken place in the city’s Warehouse District. The heavy timber framing served as a focal point of the building’s new atrium—created to bring natural light into the interior (where there weren’t any windows) and considered key to the building’s marketability.
