Changing pressure: specifying with an assembly mentality.

Specifying with an assembly mentality

With projects now being specified under UBC 97, architects need door assemblies and products that satisfy the new positive pressure and S-label requirements, while manufacturers are still scrambling to provide listed products. Responsibility for filling the information gap during this period of transition belongs to the AHCs and CDCs who serve as door and hardware specifying consultants. To specify acceptable UBC 97 solutions, specifiers will need to think in terms of the assembly. That means all sections of the specification that affect the opening must be considered and coordinated. Metal and wood frames, metal and wood doors, hardware and listed gasketing are all influenced by the positive pressure fire door test.

For AHCs and CDCs who previously provided only hardware sets - which was practical and expeditious under the bid-mill modes of negative pressure projects - this represents an expanded function in their interaction with the architect. Many consultants share the viewpoint that this "expanded" role is appropriate to their training and should have always been standard practice.

Why is the assembly mentality necessary for positive pressure specifying? In the mature negative pressure environment, years of testing have made simplified door functions available, along with the full range of labeled components familiar to us all. However, many of these functions and components have not yet been tested, or tested successfully, under positive pressure, especially for pairs of doors, and may not be available during the current development period. One example is a pair of rated doors without an overlapping astragal or channel, or exit devices less bottom rod.

All specifiers will have to be aware of these limitations, and every component will have to be verified. The requirement is to assure that all specified or approved equal products in the assembly are in compliance with the new positive pressure fire door standards, UBC 7-2 1997 and UL 10C. Assuring that the assembly itself is in compliance also requires confirming that the components are compatible and are listed with the door and frame type. To accomplish this, AHCs and CDCs will have to consider and ensure the coordination of specified products in Section 08100 (Hollow Metal), Section 08200 (Wood and Plastic), Section 06460 (Wood Frames) and, possibly, Division 01600 if electrified hardware is to be specified - in addition to Section 08710.

Section 08710 - the door hardware area of the architect construction documents - is where door hardware consultants have traditionally earned their stripes. Although architects requested consultant services in this section, they typically provided their own specification for the frame, door and other accessories. Hardware has always influenced these sections, but unless the consultant asks questions, the coordination is often overlooked. Even with routine negative-pressure specifications, this has caused problems. For example, the hardware consultant specifies top rod only fire exit hardware, and the door supplier furnishes a labeled door with overlapping astragals. That kind of error often is not detected until late in the job, after the overlapping astragal has been installed. We all know this can happen even though the door manufacturer was listed in the specification. In this case, failure to provide a thorough, professional service may result in a costly change order.

Conscientious consultants specifying under positive pressure should be on notice today that oversights of this nature are not acceptable. Positive pressure always affects other sections, and specifiers who want to do a professional job of consulting must take that into account. The necessary actions begin with advising the architect of compatibility issues and should include actively influencing - and preferably writing - the specifications for Sections 08100, 08200 and 08340 (Specialty Doors) and possibly 01600, in addition to 08710.

All accessories must also be in compliance, so the specification of glass under Section 08810 (Fire-Rated Glazing) will also need to be coordinated with other door components. Glass size cannot be just a note on the architect's door schedule. Elevations need to be verified, along with compliance of the lite kit manufacturer and requirements for the variety of lite kit designs with wire and other glass and glazing material listed for positive pressure. For example, some 20-minute combustible-core doors may have a requirement for intumescence in the lite kit to block superheated gases from penetrating to ignite the unexposed face of the door.

When architects request door hardware specifications from AHCs and CDCs, the expectation is that the consultant's specialized training and expertise will ensure a door that works properly and satisfies code. When code requirements change, the burden of reeducation also falls on the specialist. Architects will expect AHCs and CDCs to be aware of the current changes, differences in positive pressure products, and how these factors influence the assembly. If the assemblies for which hardware is specified fail to work as required or meet code, responsibility and, almost certainly, liability - will rest directly on the shoulders of the specifying consultant.

Enforcement of the new code changes, now underway, is influencing the construction documents for projects being specified. Positive pressure is being adopted today in 14 ICBO states, and code officials will be looking for positive pressure labels on doors, frames, hardware and gasketing systems. Until product availability matures, and the laboratories have enough test data to support engineering analysis of comparable products, there will be considerable scrutiny from code officials to make sure that all components are in compliance.

In fact, ITS/Warnock Hersey now requires that the installation instructions for the total assembly, including all components, be attached to the door for review and approval by the Authority Having Jurisdiction. That requirement needs to be specified in the construction documents for every door component section. Consultants will need to advise architects accordingly - and add installation instructions to the Quality Assurance paragraph.

So, what is the imperative to the door hardware consultant? AHCs and CDCs are expected to make themselves completely knowledgeable about test standards UBC 7-2 1997 and UL 10C as well as the new combined model code IBC-2000, which contains a positive pressure fire door standard. Furthermore, in order to advise the architect, they will have to become knowledgeable about door and frame products that meet hardware functional requirements. In the future, they will have to make sure the door selected has hardware application and functionality that meet specification and listed requirements as well as overall architect/project needs.

This task can be greatly simplified when manufacturers also adopt an assembly mentality. Some products have been developed as components in engineered systems, which are then tested as assemblies. The benefit of this approach is that a detailed listing of compatible hardware, doors, frames, gasketing and lite kits becomes available, along with prepared installation instructions. However, it is still incumbent upon the consultant to verify specific approved products and ensure that specification sections are adequately coordinated.

One example of this concept is a tested assembly developed by an intumescent gasketing manufacturer in accordance with the UBC 7-2 1997 fire test standard for 20-Minute Smoke and Draft Control doors - the most commonly specified fire doors in commercial buildings. Hardware, doors, frames and gasketing have all been considered and tested to meet the fire and air leakage requirements of the standard. Yet the consultant must still verify frame compatibility for either the kerf or dado intumescent gasketing system.

For proper coordination of assembly components, the specification for the gasketing system in the door hardware Section 08710 would need cross-referencing with a Section 08200 requirement for the wood door to meet the WDMA S-9 standard required for the system - and with Section 06460 to specify maximum door sizes for use with a wood frame. If kerf or standard metal frames are to be used, Section 08100 must be cross-referenced as well. Selection of additional hardware from the tested options available would be indicated in Section 08710. Coordinating the construction documents in this manner allows the consultant to ensure that tested functionality is preserved and that the assembly listing for this engineered solution is maintained.

While the change to positive pressure may force comfortable routines to change as well, professional door consultants should welcome the opportunity to perform the job for which they are trained. Professionals with AHC and CDC credentials should certainly be equipped to learn how to prepare specifications to positive pressure - and by doing so will continue to enhance the value of their services to architects. Who knows...there may even be a positive effect on projects built under old fire test standards.