WINDOWS

New fixed fiberglass exterior window glazing systems offer the design flexibility of fixed aluminum glazing systems while providing greater energy efficiency at a lower cost. The result is lower energy bills, better U-factors, greater resistance to condensation and superior thermal comfort. Fiberglass frames provide thermal expansion at the same rate as the window glazing, assuring a weather-tight seal between the frame and the glass. Glazing gaskets required with aluminum systems are not needed, thus reducing maintenance. Fiberglass is inherently a good insulator, and unlike aluminum, a fixed fiberglass frame will not need to have a thermal break. The frames can also be filled with foam insulation to provide some of the highest frame insulation values possible.

Improving Indoor Air Quality

Poor air quality and high levels of indoor and outdoor air pollutants have been linked to the increase in asthma cases in school-age children over the past 30 years.³ To reduce indoor air pollution, the EPA recommends controlling the sources of pollution, providing adequate ventilation and clean indoor air. Windows with ordinary room side blinds accumulate 200 times more of certain airborne allergens. Windows with integral between-the-glass blinds control the source of pollution by reducing the exposed surfaces for dust collection. They are easier to maintain and also provide sun controls to prevent glare and increase usable daylight in the classroom.

Speedy Construction and Preservation Tax Credits
In order to reduce energy loss, a major part of the Hotel Andaluz renovation in Albuquerque, New Mexico included replacement of the building’s 192 historic wood windows with low-maintenance aluminum-clad wood double-hung windows—with a finely detailed sash profile, simulated divided lights and authentic spoon hardware. To save installation time as well as to allow for historic tax credits, the manufacturer devised an installation procedure using a T-subframe and brickmould that allowed for the installation of the new windows without removing the existing wood frame. Although the existing sash was removed, the existing frames were left in place and covered by the new subframe with brickmould.
This detail shows how the T-subframe and brickmould were used to cover the existing wood frame. Images courtesy of Pella Commercial	Historic Hotel Andaluz replaced 192 historic windows with aluminum-clad wood double-hung windows. The architect is pursuing preservation and sustainable building tax credits for this project as well as LEED® certification.

WATERPROOFING

A unique waterproofing membrane composite with a 60-ml-thick thermoplastic membrane reinforced with a weft polyester knit fabric and a hydrophilic polymer layer that will activate and swell at any breach in the thermoplastic membrane to stop water ingress. Image courtesy of CETCO

The advantages of a new thermoplastic waterproofing membrane are that they reduce substrate preparation work and disposal, can be installed over damp concrete and that they provide superior moisture proofing. This unique thermoplastic waterproofing membrane incorporates a hydrophilic composite layer engineered to swell when exposed to water ingress through a breach in the thick thermoplastic membrane. This waterproofing membrane is installed with heat-welded seams and is reinforced with 5.0-ounce weft polyester knit fabric. This dual-composite membrane is puncture resistant, dimensionally stable and has tested for both good tensile and tear strengths. This product is engineered to resist ground water contaminants typical of below-grade conditions and is chemically resistant to oils, chemicals, salt and other contaminants. The membrane has an extremely low water vapor transmission that qualifies it as a Class “A” Vapor Retarder per ASTM E1745 and can be used as a methane barrier.

This waterproofing system provides both active and passive moisture protection. Each membrane overlap seam utilizes both a conventional weld and an overlap assembly of the membrane system with hydrophilic properties to assure water-tightness eliminating reliance on seam integrity based on adhesives or installation labor.

Roof Replacements and Waste Reduction

This high-performance waterproofing can be used both for new building construction and remedial work such as plaza and podium deck renovations, as well as roof replacements. In the online portion of this article, you will find a case study describing a roof replacement for the City of Los Angeles Police Department Heliport that met stringent code requirements. New construction applications include property line construction, backfilled walls, under slabs, tunnels and greenroofs. For remedial projects, an advantage of this system is that it can be applied directly on top of the existing membrane. This can greatly reduce the time and money spent removing the existing waterproofing membrane to the structural deck as preparation for a new membrane. Specifications for remedial projects should include proper removal of old, loose waterproofing, and any flashing materials around penetrations, drains and perimeters. For this application, the waterproofing consultant should provide a field assessment of the remaining membrane and upon review and verification.

Workers installing thermoplastic membrane waterproofing system over the existing failed rubberized asphalt membrane on the split-slab deck of this hospital. Photo courtesy of CETCO