Our thoughts, publications, white papers, research and current events.

Window and Door Design and Installation Guide

Thomas K. Butt, FAIA
Nystrom Elementary School

Nystrom Elementary School CC-ND

This post explores basic information on the design, specifying and installing doors and windows. Techniques for installation of “punched” windows and doors have been evolving continually over the last two decades. For many years, the accepted standard involved four strips of flexible flashing integrated with a nailing fin and the water resistive barrier (WRB) at the window perimeter. This concept was easy to understand and implement because the window fins, the flashings and the WRB were typically all in the same plane. It is amazing, however, that so many designers and builders were still able to get it wrong. Read More

Plaza Deck Design Primer

Thomas K. Butt, FAIA
Plaza Design, Frank Hagel Federal Building

Plaza Design, Frank Hagel Federal Building CC BY-ND

This primer points out key issues for designing and constructing a successful plaza deck system. A plaza deck is a walking surface, which sometimes can accommodate vehicles, typically waterproofed to protect the underlying structure and/or occupied spaces below. Common surface treatments include concrete, ceramic tile, stone or other paving material, usually with a bi-level drain used to accept both surface run-off and water at the waterproofing membrane level. Structural substrates are commonly wood or concrete. Read More

Westcon Tribune

Thomas K. Butt, FAIA
Avoid litigation and achieve better design and construction

Avoid litigation and achieve better design and construction, photo credit Joe Gratz. CC-ND

Architects and engineers become defendants in construction defect litigation because of allegations that they breached the standard of care – that is, they practiced in a negligent manner that caused or contributed to a construction defect that resulted in damage to someone. Tom Butt's presentation at the Westcon symposium included remarks about construction litigation in general, the design professional’s standard of care, using standards to avoid litigation and achieve better design and construction, and tips to avoid waterproofing failures. Read More

Water Resistance and Vapor Permeance of Weather Resistive Barriers

Thomas K. Butt, FAIA
ASTM International is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services

ASTM International. CC-ND

This paper, which is limited to the properties of water resistance and water vapor permeance, provides information that may be helpful in understanding, selecting, and using weather resistive barriers. Weather-resistive barriers (WRBs) are typically used in exterior walls of low rise frame buildings under claddings such as stucco (cement plaster), wood and wood derived products, vinyl (PVC), and masonry veneer. WRBs are primarily intended to provide resistance to water that may penetrate the outer cladding. WRBs also provide resistance to passage of air to varying extents but generally are moderately permeable to water vapor. Traditional WRB materials were limited to asphalt saturated felts and papers, but polymeric sheets have taken a growing share of the market in recent years.
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The Enduring Mystery of Weather Resistive Barriers and the Need for Standards

Thomas K. Butt, FAIA

Santa Ana Federal Building Water Intrusion Investigation & Repair Design, Santa Ana, CA, Attribution-NoDerivs CC BY-ND

This PowerPoint Presentation by Tom Butt was delivered at the Westcon ASTM E 2266 Seminar. "The Enduring Mystery of Weather Resistive Barriers and the Need for Standards" covers drainage walls, weather resistive barriers, common use and misuse of terminology, the California Building Code, and much more. Read More

Soffit/Weep Screeds in Cement Plaster (Stucco) Construction

Thomas K. Butt, FAIA

Stucco remains one of the most popular cladding materials in the west and southwest United States. Photo credit Dante Alighieri CC-ND

Conventional stucco, also called cement plaster, is a mixture of Portland cement, sand and water, to which plasticizers, traditionally lime, are often added to increase workability. In wood frame construction, stucco is usually applied in three coats over metal reinforcement (lath), with or without solid backing. Properly used, stucco is a desirable cladding material that is hard, strong, fire-resistant, rot and fungus resistant and durable. It adapts to any shape, is low in first cost and
has minimal requirements for maintenance. It remains one of the most popular cladding materials in the west and southwest United States. In spite of its many advantages, stucco has, when misused or abused, distinct undesirable characteristics that can cause or contribute to serious problems or construction failures. The undesirable result most often seen is water intrusion resulting in damage to structure or building contents. Read More

Weather Resistive Barriers and Flexible Flashings

Thomas K. Butt, FAIA
Presentation delivered at the American Architectural Manufacturers Association (AAMA) Western Region Meeting. Read More

Hardboard and OSB Siding

Sharon M. Waterman, AIA
Many manufacturers of hardboard and oriented strand board (OSB) siding have been hit with class-action lawsuits across the country. Read More

Performance of Asphalt Fiberglass Shingles

Sharon Waterman, AIA
Asphalt Fiberglass Shingles

Asphalt Fiberglass Shingles CC-ND

Roofing specification writers should be cautious and be aware that not all asphalt fiberglass shingles are created equal and that stated warranties should not be regarded as insurance policies. Horizontal or vertical splitting or cracking of fiberglass shingles has been a concern in the roofing industry over recent years. Following complaints from roofing contractors, studies done by the Western States Roofing Contractors Association in 1992 and 1995 showed that asphalt fiberglass shingles, particularly the 20-year guaranteed shingles, were failing prematurely, some as early as six months, with average failures occurring at about five years. Read More

Limiting Construction Failure Losses – A Challenge for the Insurance Industry

Thomas K. Butt, FAIA and John E. Clinton, SE, AIA
A primer on construction failures. Why do they occur? How is the insurance industry affected? Building failure litigation - who is responsible? Read More