By Drew Parks
The creation of drawings and specifications for any construction project is a complicated business. First, the general conditions must be outlined, all appropriate references identified, and contractual obligations listed. Then, each section must clearly inform the bidder of the scope of work and its specifications. If a specifier wants to retain sanity in this process, every resource that can add credibility and accuracy to their document must be accessed and mined.
The content in many sections of bid documents is already benefiting from collaborations with the affiliated trade—structural, electrical, mechanical, and door hardware professionals all provide much needed input and follow up inspections to ensure the quality of the bid documents and the finished product. The architect and specifier cannot be expected to be experts on every aspect of building construction. Their job should be to create the vision, identify the detailing requirements, and corral the trade expertise needed to put their vision on paper for bidding and fabrication.
One area of the building finishes, for which available resources have not been fully tapped by the specifier, is the interior product collectively known as ‘millwork.’ Such materials are identified in the architectural woodwork, laminates, panelling, wood doors, and laboratory cabinet sections of MasterFormat—respectively, 06 41 00, 06 42 00, 06 46 00, 08 14 00, and 12 35 53. The items governed by these sections are often the first things seen when entering a lobby, boardroom, store, suite, or office. They are one of the principal elements that contribute to ‘first impressions’ and quality assessments.
Unfortunately, the writing of these sections is often a source of frustration for the specifier. Accurate material and construction details are difficult to nail down, and clear identification of these elements in the bid drawings and specifications is a time-consuming process. Inconsistencies in the final specifications and drawings can plague the architectural firm, general contractor, and millwork firm throughout the bid and building process.
This article examines how resources from the Architectural Woodwork Manufacturers of Canada (AWMAC) can help design/construction professionals in this regard. The goals are:
- less work for the specification writer and for the plans draftsperson;
- more concise and accurate bid specifications as well as drawings;
- fewer questions and addenda before bid closing;
- bid proposals on a relatively level playing field and based on the production of a good-quality product;
- extended life expectancy for properly installed products; and
- securement of a two-year guarantee on the millwork components of your project.
Understanding millwork’s evolution
Millwork production and installation has changed dramatically over the last generation. Once the domain of the finish carpenter, the trade now comprises a team of specialists:
- shop drawing technicians;
- computer numerically controlled (CNC) equipment programmers;
- machine operators;
- shop finish applicators;
- site installation crews; and
- project managers.
The manufacturing facility has evolved from the backyard shed or garage to larger industrial spaces filled with CNC machinery. The capability of the local manufacturing process has also evolved. It was not that long ago that low-tech manufacturing methods restricted the buyer to simple design and materials. Unique elements resulted in extra costs generated by labour-intense processes and limited access to ‘special’ materials. For years, complicated features such as carved elements, large interconnected pieces, multiple colour patterns, and inlay designs were only available with a large price tag. Today, the availability of new and reimagined materials and the detail and speed of computerized machinery has opened the door to ‘sky-is-the-limit’ design.
For the specifier, the downside of this new design opportunity and industry change becomes the complications of getting the vision details recorded in words and drawings for the bid process and, ultimately, in the translation of those specifications into the final installed product. The architect and specifier are expected to control all aspects of the building design, from foundations to finishes. The idea the architect, designer, and specifier can also be trade experts who understand all the intricacies inherent to each discipline is simply unrealistic.
Each qualified tradesperson has tens of thousands of hours of training and work experience; each trade’s business place usually relies on specialists within its own ranks. To adapt to this reality, the specifier community has developed links with the individual trades—consultants, inspectors, and engineers—to ensure the myriad details are looked after and a good product is controlled and produced for the owner.
By Jeff Halashewski, Dipl Arch Tech
Over the past year, this author has witnessed an increase in the design community’s awareness of the seismic requirements set out for Canadian jurisdictions. However, for both new buildings and existing construction, the destructive effects of earthquakes can be of significant concern. Damage to inadequately restrained key systems within buildings can be extensive. When a major component, such as a generator, is knocked off its supporting structure, the fall can threaten both life and property. (The author drew on information provided in product literature from USG and Bailey Metal Products Limited in developing this article. It also relies on information from CSA Group’s Technical Committee on Seismic Risk Reduction of Operational and Functional Components [OFCs] in Buildings, S832-14, along with the Ontario Association of Architects (OAA) Practice Tips 35.)
The cost of properly restraining such equipment is insignificant compared to the associated costs of replacing or repairing the components, along with the expense of system downtime due to damage to the building services and businesses. When thinking of it from this angle, whose responsibility is it to restrain a generator—the building owner or tenant?
This author’s previous article for Construction Canada explored why proper restraining of nonstructural components can reduce the threat to life and minimize long-term costs due to damage and associated loss of service. (In the November 2016 issue of Construction Canada, this author discussed the basic concepts that feed into larger discussions regarding ‘domestic’ earthquakes, nonstructural components, and methods of selecting seismic restraints. Click here.) It stressed the importance of minimizing risks at the design stages, which should include a well-written specification that can be taken to the delegated design engineer or person producing the shop drawings for the given component.
In this follow-up article, the author explores how this information can actually be implemented, working through the processes of setting up the performance requirements through to submittals, fabrication, inspections, and quality assurance/control (QA/QC). The goal is to be able to easily understand what is required as part of the specification for any given building.
What is a seismic restraint?
By definition, a restraint is a method to mechanically control movement, whether via dampers, bracing, containment, immobilization, or suppression. Seismic forces relate to vibrations produced by an explosion or even by the natural environment—for example, a building on the banks of a fast-moving river will experience vibrations within. With respect to ‘seismic restraints,’ then, design professionals have no control over the first word, and therefore must focus on the second—controlling the parts of the building that will move.
Seismic restraints can fit into many categories, but the most common are:
- fully restrained;
- partially restrained; and
Each type of these assemblies has its pros and cons, but it all comes down to the intent and the seismic force potential on the component requiring restraint, either being surface-mounted, suspended, or supported off another nonstructural component. The materials used can vary, ranging from those like concrete, steel section, springs, cables, rods, and premanufactured solutions.
By Michael Russo
The advantages of a built-up roofing (BUR) assembly include long life, a variety of maintenance options, and outstanding puncture resistance. This durability means property owners will spend less time worrying about fixing leaking roofs and the associated hassles—lost productivity, disruption in operations, slips and falls, repair bills, and other liabilities.
Recommending clients install a roof system that gives them the best chance of eliminating unproductive distractions is a good business decision for design/construction professionals. A more durable roof will enable property owners to focus on making profits instead of dealing with the aftermath of a roof leak.
“I have no problem with endorsing built-up roofing,” says Luther Mock, RRC, FRCI and founder of building envelope consultants, Foursquare Solutions Inc. “The redundancy created by multiple plies of roofing felt is really what sets BUR apart.”
One can argue BUR’s closest cousin—which is the modified bitumen (mod-bit) assembly—is actually a built-up roof made on a manufacturing line. The reality is the plies of a BUR create a redundancy that can exceed any potential oversights in rooftop workmanship.
“I’ve replaced BURs for clients I worked with 30 years ago,” says Mock. “We recently replaced [a BUR] specified in the early 1980s. And the only reason was because some of the tectum deck panels had fallen out of the assembly. Meanwhile, the roof was still performing well after 30 years.”
According to the Quality Commercial Asphalt Roofing Council of the Asphalt Roofing Manufacturers Association (ARMA), one of the main drivers of the demand for BUR systems is the desire of building owners for long life cycles for their roofs.
“A solid core of building owners and roofing professionals in North America continue to advocate hot-applied asphalt systems because of their long lives,” says Reed Hitchcock, the group’s executive director.
Benefits with BUR
Over the years, BUR assemblies have earned a reputation for reliability with building owners, roofing consultants, architects, engineers, and commercial roofing contractors. The original price tag tends to be greater than other low-slope roofing options, but these assemblies offer competitive life-cycle costs. BUR enjoys a track record spanning more than 150 years; it provides a thick, durable roofcovering and can be used in a broad range of building waterproofing applications.
Available as part of fire-, wind-, and/or hail-rated systems, BUR assemblies offer waterproofing, high tensile strength, long-term warranties, and a wide choice of top surfacing (including ‘cool’ options). Their components include the deck, vapour retarder, insulation, membrane, flashings, and surfacing material. The roofing membrane is made up of two components—felts and bitumen. The former strengthens and stabilizes the latter, which serves as the waterproofing agent and adhesive for the system.
The roofing membrane is protected from the elements by a surfacing layer—either a cap sheet, gravel embedded in bitumen, or a coating material. Surfacings can also enhance the roofing system’s fire performance rating.
Another potential surfacing option is gravel, commonly used in Canadian applications where the additional weight on the roof system would not be a problem. There are also several smooth-surface coating options, the most popular of which are aluminum or clay emulsion products offering greater reflectivity than a smooth, black, non-gravel-surfaced roof. These reflective roof coating options are typically used in warmer regions of Canada when required by code.
By Douglas Bennion
Successful independent field-testing and code compliance analysis in British Columbia has resulted in the compilation of the first comprehensive set of residential construction details for insulating concrete forms (ICFs) in North America. (An earlier version of this article appeared in the September 2016 issue of ICF Builder.) From footings to trusses, the ICF details presented in the provincial Homeowner Protection Office’s (HPO’s) upcoming release, “Building Envelope Guide for Houses,” offer a concise and cost-effective path to best practices and B.C. code compliance. Ongoing efforts indicate a strong potential for expanded adoption of these details in jurisdictions across Canada.
Many different methods—and even more opinions—exist on weatherproofing ICF walls. Only recently has the industry had scientific evidence upon which to base best practices for installation of window and door openings in such walls. “ICF Field Testing Report,” a research report issued by HPO, provides a range of solutions compliant with building codes such as the B.C. Building Code, Part 9 (which is modelled after the 2015 National Building Code of Canada [NBC]). These solutions address the widest-possible range of building types, from single-family homes to high-rise commercial buildings.
To convey the report’s findings and make them easily applicable to individual projects, it is best to start at the core of the issue—how to permanently prevent air and water leakage at window and door openings in ICF walls. The answer begins with the following two basic code-compliant paths to water resistance in building shells.
Moisture protection plane
Mainly concerned with wood-framed walls, building codes typically call for a primary weather barrier (such as siding or stucco) with a secondary weather barrier (such as building paper or another synthetic membrane) behind it. This is because framed walls must be kept dry to protect against moisture damage to both framing members and the insulation within.
Both codes, however, contain exemptions from the secondary weather barrier requirement in the case of above-grade masonry or concrete walls, which are recognized as watertight planes and shed water adequately on their own. As a result of the research summarized later in this article, ICF walls are now characterized as a complete assembly under B.C. residential code, without the benefit of added building paper or air gap (i.e. rainscreen) behind exterior cladding. This means ICF walls will not be subject to the same requirements for added weather protection as wood-framed walls, but the same exemptions as other concrete and masonry walls, which are recognized as able to resist water penetration on their own, without added layers of protection.
The expanded polystyrene (EPS) used in the manufacture of ICFs will not permit the passage of water or water vapour, but the horizontal and vertical joints between ICF units can allow penetration of water driven either by wind or gravity. This is an apparent conflict with building codes, which typically require the exterior building shell to be able to shed water to the outermost plane of the wall, where it cannot harm wood framing. Unable to view concrete behind the ICF outer insulation, building officials often default to more familiar wood-framed construction requirements and expect a membrane between the building sheathing and the exterior cladding. This has not only proven to be unnecessary, but is also unpopular among ICF proponents who object to the added costs.
By Darja Majkoviˇc, PhD, Jure Šumi, and Cristina Senjug
Vegetated roofing has long been recognized as an effective stormwater management tool in urban centres to help store and attenuate runoff from impervious rooftops. New technological advancements are helping further increase stormwater retention capacity on rooftops while keeping weight low. One such significant advancement is the use of rock mineral wool (RMW)—which offers both advantages—in place of a greater depth of traditional growing medium.
There are several varieties of mineral wool on the market, produced for different applications. When it comes to stormwater retention and vegetated roof survivability, not all mineral wools are created equal. As the lifespan of vegetated roofs may be several decades, it is imperative to understand the differences in varieties of RMW, as well as their effectiveness and durability as stormwater management tools.
Mineral wool is a general term for a light, artificial wool made of an inorganic substance such as glass, stone, or slag. It was originally invented in the mid-19th century for thermal and acoustic insulation in the construction industry.
Almost 50 years ago, a modified form of RMW in the form of slabs, blocks, and bonded fibres started being used as a substrate in hydroponics in Denmark. (For more, read the 2002 article, “Substrates and their Analysis” by M. Raviv et al., published in D. Savvas and H. Passam’s Hydroponic Production of Vegetables and Ornamentals by Embryo Publications in Greece.) Today, it is present in virtually all advanced horticultural markets, and is used for growing hydroponic fruits, vegetables, herbs, and flowers.
RMW for vegetated roofing applications is manufactured by a fiberization process induced by heating a mixture of various rock components (usually diabase, dolomite, granite, basalt, etc.), which are melted together at high temperatures. (Further information on mineral wool production can be found in B. Širok et al.’s 2008 publication Mineral Wool Production and Properties from England’s Woodhead Publishing Limited.) The melt is spun into thin fibres on fast-rotating machines and is later bound for dimensional stability.
Generally, there are two major differences between methods of making the loose, melted rock fibres dimensionally stable and transforming them into slabs, blocks, or wool. They can be bound using a chemical-free needling process to physically interconnect loose fibres, or those loose mineral wool fibres can be glued with binders. Examples of the latter option include:
- sodium silicates;
- melamine urea formaldehyde;
- resin-based phenolic; or
- furane-based resins. (From Kowatsch’s article, “Mineral Wool Insulation Binders,” published in Phenolic Resins: A Century in Progress from 2010.)
Advancements have been made in the manufacture of mineral wool over the decades, offering environmental alternatives and products with superior performance.
One development has been the use of formaldehyde-free binders, which rely on renewable resources. This new generation of mineral wool is an environmentally responsible alternative to phenol-based products. It uses renewable resources for binding agents and has enhanced water absorption characteristics.
The most notable development is the production of the needled rock mineral wool, manufactured without additives or binders. It is important to understand how this engineered product supports long-term stability and stormwater retention performance in outdoor applications such as vegetated roofing.