Common Questions Engineers Ask about Chimney Specifications

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Common Questions Engineers Ask about Chimney Specifications

As every engineer knows, they are ultimately responsible for reviewing the specs and scope of a new project they are given, no matter how complex and vast. For example, for new construction, a mechanical engineer might be responsible for detailing all the information needed for the boilers, pumps, water heaters, cooling towers and much more, creating specifications for each. At Schebler, we have assisted numerous engineers in creating accurate and reliable chimney specifications. The below questions are a sample of those we hear most often.

Is There a Specific Tool or Resource I Should Use?

Many engineers heavily rely on MasterFormat, developed and produced by the Construction Specifications Institute, to develop their engineering specs. Updated roughly every two years, MasterFormat is “the construction industry’s leading standard for organizing building lifecycle data across phases of development.” Engineering firms will often have their own customized versions of these specifications, developed over time—adding helpful notes and personal recommendations for every aspect of the system, including chimney specifications.

MasterFormat may appear daunting due to its size and all the details it provides. To make it more searchable and usable for engineers and other construction professionals, MasterFormat contains several “Divisions,” which are then broken into more specific “Sections.” When MasterFormat was first released in 1973, it included only sixteen Divisions. Today there are fifty. Division 23 contains all HVAC specs, and Section 23 51 00 pertains specifically to Breechings, Chimneys and Stacks.

Can I Do This Myself, or Should I Work with an Experienced Specialist to Develop My Chimney Specifications?

You can always create chimney specifications yourself, and seasoned experts sometimes do, but with fifty divisions, each with numerous subsections, finding the right MasterFormat information can be challenging. Dozens, if not hundreds, of sections could apply to an engineer’s scope on a project. Each requires detailed knowledge of those systems to create project-appropriate specs.

Working with a trusted partner with a niche specialization helps ensure the most current information is being used and the specs are accurate. This specialized expertise can save engineers significant time, eliminating the need for frustrating and ponderous searches and cumbersome investigations. Working with a specialist also means bringing deeper expertise into your chimney specifications and, ultimately, more certainty to the project. Simply put, engineers can’t know everything, but the good news is that they don’t have to.

An experienced engineering and manufacturing partner can help you make sure the correct details are included.

For example, generator exhaust systems have a lot of specific key components that impact safety and performance because of the need to deal with very high temperatures and gas expansion. Field-fabricated systems have been the go-to solution for generator exhaust for decades—but prefabricated systems have become the established replacement, saving time and improving safety. If your generator exhaust spec only includes field-welded products and doesn’t allow for prefabricated options, you may be making a costly mistake.

Are Chimney Specifications “One Size Fits All”?

As every engineer knows, every project is unique, and your chimney specifications are no different. One thing we see at Schebler, now more than ever, is that specs have become vaguer. To a degree, this is understandable—engineers want the vendors quoting their projects to have some flexibility in choices pertaining to manufacturers and products. But it also introduces the potential for risk.

Not customizing the specs to include important product details that pertain to safety, efficiency and performance often pave the way for inferior products to be used. These items may technically fulfill the spec, but they won’t provide the best or safest results. Understanding what customizations need to be made isn’t always easy or intuitive, and it may be impossible for an engineer to know unless they have recent, in-depth experience with particular systems.

How Do I Ensure I Have the Most Up-to-date Information?

The MasterFormat is updated every two years, but it’s common for engineers to work with their internally customized versions of the specs, many of which have not been updated for a long time. At Schebler, we often see specs that are out-of-date in various ways, such as the following:

Naming a manufacturer that no longer exists or a material that’s no longer sold.
Specifying a material that may have once been standard but now has newer, improved options that may also be more cost-effective.

Before submitting chimney specifications, it’s always a good idea to have an expert review them. This can help ensure that the most up-to-date products and solutions are included.

How Can I Maximize Safety and Minimize Risk?

Most specifications will adhere to code requirements—and sometimes, that’s enough. But more often than not, minimum compliance with the code may not guarantee safety in a real-life situation. To avoid this scenario, you should make a habit of calling out specific product features and requirements in the chimney specifications that can make a difference in safety and performance. You should also make sure you insist on the use of high-quality products, as in the following examples:

UL testing/listing. UL listed products are available for a wide variety of applications. Always include appropriate UL listings in the specs when it’s an option.
RapidLock^® Connection System. A Schebler-exclusive system, this is a unique one-piece band for joining chimney sections. It eliminates the need for added nuts and bolts, reducing installation time and expense.
UL listed gasket. Another Schebler exclusive, our grease duct products now come standard with a first-of-its-kind UL listed gasket that eliminates the need for sealant—speeding up installation time and reducing the possibility of improper sealant use that could result in leaks.
Insulation thickness. If the inches of insulation required for a system aren’t specified clearly, one vendor may quote a product with 1” of insulation, and another might quote a product with 4”. Of course, the 4” product will be more expensive, but it may also be the safest and correct choice for the system. While a bid with the 1” product may win because of its lower price, it could heighten fire risk. In situations where the building owner may have policies dictating that the lowest bid must be accepted, these details are critical for ensuring safety.

Unfortunately, mistakes in the specification stage can lead to costly issues down the road. It’s a reality that getting a spec wrong can open you up to not just system performance or compliance issues but customer dissatisfaction, financial liabilities and even litigation.

Always overestimate the requirements, so you aren’t taking needless risks. For example, let’s say the code requires a flow rate of 500 CFM for grease duct systems. In this case, we recommend that you specify between 1,500 and 1,800 CFM because it will help get grease through the system faster and prevent it from solidifying as quickly. This reduces fire risk because that grease build-up is ultimately the fuel for a fire.

The Importance of Accurate Chimney Specifications

Every engineer wants to ensure they’re guaranteeing life safety—not allowing exhaust back into a room, for example. Designing a system that fulfills project requirements while also building the engineer’s reputation and credibility ultimately helps grow their business—and that starts with proper specifications, including chimney specifications. Good specs tend to lead to good installations, demonstrating the ability to design highly efficient, safe and cost-effective systems.

At Schebler, we’re here for you as an engineer—our team is standing by to answer your questions and help you ensure your chimney specifications are complete, accurate and best suited for project success.

Schebler has Section 23 51 00 specifications for all of our products:

You can download editable Word documents of these for free, and it’s a great place to start. But be sure to contact us for more detailed and dedicated assistance.