What Is Metal Deck? Definition, Types, And Uses Of Metal Decking
Have you ever heard the term “metal decking” or “steel decking”, and wondered what it actually means? Maybe you have a set of plans with metal decking specified and you need to learn more about it. We will cover all of the basics in this article.
At Western Metal Deck we’ve been supplying metal decking for thirty plus years. Our goal is to answer all of our customers questions from the simple ones to the complex ones. So, let’s start at the beginning with a definition of metal decking.
In this article we will cover:
- What Is Metal Decking?
- Additional Terms For Metal Decking
- Uses Of Metal Deck
- Types Of Metal Deck
What Is Metal Decking?
Metal decking is corrugated metal sheeting that’s used as a structural roof deck or composite floor deck. It will be supported by steel beams or joists. The purpose of metal deck is to support the insulating membrane of a roof or to support and bond with the concrete to create a composite metal floor deck.
Metal decking has a high strength-to-weight ratio which decreases erection and material handling cost. It’s an ideal product for multi-story buildings. It’s the perfect platform for a roof or a concrete floor.
Other Terms For Metal Decking: Steel Decking, Pan Deck, And Q Deck
There are quite a few names for metal decking, but they all mean the same thing. So, just in case you hear any of these terms you will know what they mean.
What Is Steel Decking?
Steel decking is just another term for metal decking. If you are on the West Coast, then it's more likely to be called metal decking. Conversely, if you are located on the East Coast then it’s more likely to be referred to as steel decking.
There is an alternative definition that would not apply to steel erection. There is a different product known as Steeldeck that can be used as a portable and economical portable staging system.
What Is Q Decking?
Q Decking is the original metal decking invented by the HH Robertson company in the 1960s. It was a composite floor deck called Q-Lock Floor and was available in 2” and 3” depths. Q decking is not available nowadays and when people ask for Q Deck, it’s typically just a generic term for metal decking.
What Is Pan Decking?
Pan Decking is a stay in place metal form that was used from the 1940s through the 1960s. When people ask for pan decking, they are usually just inquiring about metal decking.
Uses Of Metal Decking
Metal decking has two primary uses: structural metal roof deck and composite floor deck. It’s perfect for both applications because it has a high strength-to-weight ratio that’s both inexpensive and easy to install.
Metal Roof Decking
Metal roof decking is a corrugated metal panel that’s used for a roofing application. It’s installed over steel joists or steel beams and provides a durable platform for the installation of roofing materials, insulation, the waterproof membrane of a roof, and lightweight concrete. Metal deck is attached by welding, mechanically fastening, or screwing the metal sheets to the steel.
Roof decking has a smooth surface without embossments and isn't designed to have structural concrete poured on top of it. If you require structural concrete and a composite floor deck system then you will need a metal floor deck.
Uses For Metal Roof Decking
- Supports the roof system of a building
- Mezzanines, which are intermediate floors in a building and covered with plywood.
- Steel canopies, which are an overhead structure that provides shade and shelter.
- Trash gate enclosures and roofs
Metal Floor Decking
Metal floor decking is a corrugated metal panel that’s used in a floor application. It’s installed over steel joists or steel beams and supports the wet concrete. There are embossments in the vertical ribs of the decking that bond with the concrete slab. When the concrete cures it becomes a composite floor deck, which will increase the strength of the floor without adding any additional weight.
Uses For Metal Floor Decking
- A working platform when building multi-story buildings
- To stabilizes the frame of a building
- Stay in place form for concrete
- Composite floor deck system that carries the design loads of the building
- Mezzanines, which are intermediate floors in a building and covered with concrete.
Types & Profiles Of Metal Roof Decking
The two more common types of metal roof decking profiles that are readily available are: B deck and N deck. There are also two other types of metal roof decking profiles: types A & F Deck. These two types are less commonly specified on construction projects and aren't as readily available.
This is the most common type of metal roof deck. The primary application is to support a built-up roof system. B deck is used when you have a span that is under ten feet.
It’s available as light as 22 gauge and as heavy as 16 gauge. B Deck is 1.5” deep and 36” wide
This type of metal roof deck is used when you have a long span condition that’s greater than ten feet. Type N roof deck is available as light as 22 gauge and as heavy as 16 gauge. It’s 3” deep and 24” wide
This is the newest type of metal roof deck. It’s very similar to N Deck, but there are two important differences. HSN3 is 32 inches wide, which requires less time to install. The ribs are also at more of an angle. This makes breaking the sheets from the bundles much easier.
Similar to N Deck, it’s also used when you have a long span condition that’s greater than ten feet. Type HSN3 roof deck is available as light as 22 gauge and as heavy as 16 gauge. It’s 3” deep and 32” wide.
If you would like to learn more about B Deck or N Deck we suggest that you read:
A DeckType A deck aka Narrow Rib is an older version of metal roof decking. This panel is 1 1/2" deep, 36" wide. The spacing between ribs is only 1", which is why it is also known as narrow rib. In comparison, the spacing between ribs on type B deck is 2 1/2". The narrow spacing between ribs makes Type A deck a weaker panel. This type of panel is mainly used in repair or patchwork when trying to match the existing metal decking on older buildings.
F DeckType F deck is 1 1/2" deep, 36" wide. It is an intermediate rib metal roof deck. The spacing between ribs is 1 7/8", which is narrower than B deck, but wider than A deck. The panel offers more strength than type A deck, however B deck is a stronger panel. Type F deck is mostly used on repair work where they are looking to match the existing decking on older buildings.
Types And Profiles Of Metal Floor Decking
There are three metal floor decking profiles that are readily available: 1.5”, 2”, and 3” deep. The key difference between the three is the strength of the panel. As the panel gets deeper it becomes stronger. For example, a 3 inch floor deck is stronger than a 1.5 inch floor deck.
B-36 formlok can accommodate a slab thickness as low as 3.5 inches in depth and up to 7.5 inches high. It’s used in short span conditions.
This floor deck is available as light as 22 gauge and as heavy as 16 gauge. B-36 Formlok is 1.5” deep and 36” wide.
W2-36 formlok can accommodate a slab thickness as low as 4 inches in depth and up to 8 inches high. W2-36 is stronger than B-36, but not as strong as W3-36.
It’s available as light as 22 gauge and as heavy as 16 gauge. W2-36 Formlok is 2” deep and 36” wide.
W3-36 Formlok can accommodate a slab thickness as low as 5 inches in depth and up to 9 inches high. W3-36 is the strongest metal floor deck.
It’s available as light as 22 gauge and as heavy as 16 gauge. W3-36 Formlok is 3” deep and 36” wide.
If you would like to learn more about composite floor deck we suggest that you read: What Is Composite Floor Decking & How Does It Work?
Learn More About Metal Decking
Metal decking is an excellent choice as a roof or floor decking because it’s inexpensive, lightweight, installs quickly, and it’s easy to install.
Now that you know the basics we would like to introduce you to our Metal Decking Learning Center. We have articles and blogs on everything that you need to know about metal decking.
About Paul Rubio
Paul Rubio is the Vice President and one of the owners of Western States Metal Roofing. He has been in the metal roofing industry for 25 years. WSMR is a manufacturer of metal roofing, wall panels, and metal siding. We have colors and finishes that nobody else has with nearly 100 different colors in stock. Our selection of color options and finishes is likely the largest in the industry.