What Are Deck Flutes And What Do They Do?

Deck flutes are simply the gaps in steel roof decks. Other names for these features could include ridges, channels, or troughs. During the construction of a roof or roof retrofit, it could be important to know the flute-span capability of the steel deck panels. This measurement can help determine the type of material that can be placed over the steel decks or used to fill the deck flutes. Only an experienced roofer can make these crucial calculations that can significantly impact the success of the roofing project.

Types of Deck Flutes

Not all deck flutes are the same. There are different types of deck flutes that create unique profiles for steel roof decks. Different deck flutes not only have different spacing widths, but also different rib depths. Common types may include:

• Narrow-rib deck flutes (Type A)
• Wide-rib deck flutes (Type B)
• Intermediate-rib deck flutes (Type F)
• Deep-rib deck flutes (Type N)

These variations may serve different purposes and have different flute-span capabilities. It is essential to understand the various types of deck flutes, as they can impact specific attributes of the roofing project, such as the material to use for cover boards and the location of fastener attachment..

What Is the Purpose of Deck Flutes?

The answer will vary across different projects. Deck flutes can serve multiple roles in the roofing industry, depending on the type of deck and roofing project. The primary purpose of deck flutes is to maintain structural stability and prevent water from accumulating on the metal roof.

Stability

One of the primary purposes of deck flutes in roofing is to provide stability. The size and capability of deck flutes contribute to the strength and stability of the roof. Depending on the specific deck profiles, deck flutes can make roofs sturdy enough to walk on for the purposes of installing insulation, for example.

Flute-Span Capability

Deck flutes are crucial to structural integrity. Their span capability affects how heavy a load the material installed above the steel deck can withstand. Flute-span capacity must be carefully considered during the construction of a roof. Not only does the roof need to remain stable across its lifespan, but it must also be able to safely support the weight of both roofers and their equipment during the roof construction.

Drainage

Drainage may be another consideration when using deck flutes. In some cases, flute fillers are used as a draining system to direct water away from the roof. You can imagine them as very small gutters that work together for efficient drainage.

For composite decks, deck flutes can be useful in deterring water build-up between the steel and poured concrete, which could cause additional problems down the line. Drainage can be a significant concern for buildings, as water damage, including mold and mildew, can be a costly problem.

Flute Fillers and Retrofit Roofs

Flute decks may also play an important role in roof retrofitting. When used for this purpose, flute span capability is a key consideration. For many metal roof owners, deck flutes might not be considered at all until it’s time to retrofit the roof.

Retrofitting is often preferred over replacing the entire roof system. Not only is it less expensive, but it can also eliminate the need to close a business or temporarily relocate due to repairs. In some cases, not every roof can be retrofitted. A roofing contractor will assess the roof’s suitability and provide recommendations for retrofitting or re-roofing.

What Role do Deck Flutes Play in Retrofitting Roofs?

During a roof retrofit, the deck flutes must be properly filled with an approved filler. Filling the flutes of the structural steel decks with high-quality filler essentially converts the existing roof into the decking or substrate for the new roof, making a flat bottom for the roof’s foundation. This filler is usually made of extruded polystyrene. Once the flutes are filled, your roofing contractors can then begin adding the insulation, coverboard, and waterproof membrane for your new roofing system.

Preparing for the Roof Retrofit

Filling the flutes must be a key consideration during the planning phase of a roof retrofit. Not all foam fillers are alike. Ordering foam filler customized to the size of the deck flutes is a crucial part of the roof retrofitting process and must be done prior to constructing the new roof. It could take two months or more to obtain the custom filler necessary for the retrofit, so plan accordingly.

The Role of Deck Flutes in Acoustical Steel Decks

Acoustical steel decks are unique and therefore require unique materials. Deck flutes may play a specialized role in the construction of acoustical steel decks. These deck types differ from traditional steel decks, as their flutes are dotted with perforated holes. A special type of foam is then used to fill the deck flutes, dampening noise and reducing reverberation.

Why Choose an Acoustical Deck?

Acoustical decks are primarily used for soundproofing a building. Individual consumers and homeowners don’t typically opt for acoustic decks, as they serve a very specific purpose and can be expensive. Acoustical steel decks are often used during the construction of gymnasiums, theaters, and other buildings where sound reduction is a key priority.

Types of Acoustical Decks

There are two types of acoustical steel decks: cellular and non-cellular acoustic decks. Non-cellular decks are the standard option. Cellular acoustical decks feature an additional perforated plate on the underside of the deck for enhanced insulation and improved sound dampening. These types of acoustical decks may be more effective in reducing sound, but they are often more expensive due to the additional material required for their construction.

Dovetail Decks

Another unique type of fluted deck is the dovetail deck. Dovetail decks represent a special case where deck flutes actually play an aesthetic, rather than a solely functional role. Dovetail decks are relatively rare and may be used on historic buildings or those with a distinctive design. Log structures in the Appalachian mountains commonly use a style of dovetail deck known as Appalachian Dovetail. [1]

In this type of deck, flutes are arranged in a pattern of V-shapes to create a corrugated look. Their use isn’t solely cosmetic. This type of deck also provides a robust platform for enhanced stability and capability.

More Information on Deck Flutes

Deck flutes come in various forms and play different roles for different roofing projects. For such a simple feature, specifications for deck flutes can be quite complex. For additional information about deck flutes, it may be best to contact a professional roofer. Many roofing contractors have years of experience working with various deck types and can recommend the deck products or services you need for your metal roof.