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What Gauge is Metal Decking? Common Metal Deck Thicknesses
Kathy Midence

By: Kathy Midence on May 8th, 2020

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What Gauge is Metal Decking? Common Metal Deck Thicknesses

Metal Deck | Composite Floor Deck | Form Deck | Gauge | Roof Deck

If you have ever purchased metal, then you’ve been asked to specify the thickness or what gauge needed. If you are purchasing metal deck, then be prepared to be asked this same question. This is because there is a wide range of steel thickness. In general, steel sheet metal can range from 7 gauge to 30 gauge. However, the range of gauges that metal deck is manufactured in is a smaller range.

Metal decking is a structural component in the construction of buildings engineered to be used in roof and floor systems. It is capable of spanning different distances depending on a number of conditions. One of the major conditions is the gauge (thickness) of the metal decking.

Depending on the type of metal deck that you need there will be a different availability of gauges. For example, metal roof decking is available in different gauges than metal floor and metal form deck.

At Western Metal Deck we know that each project is engineered differently; one gauge won't cover all jobs. To help keep your job running smoothly, we stock multiple gauges, types and lengths.

In order to assist you on your next metal deck order, we will go over the different types of gauges for the different types of metal deck. We will go over:




What Is A Metal Deck Gauge?


The metal deck gauge is a unit of measurement that refers to the thickness of the steel. The larger the gauge number, the thinner the steel is. For instance, 16 Gauge is thicker than 20 Gauge, and 22 Gauge is thinner than 18 Gauge.

Below is a chart of typical thicknesses in inches for each gauge commonly used in metal deck.

Gauge Thickness in Inches
26 .0179
24 .0239
22 .0299
20 .0359
18 .0478
16 .0598


A thicker gauge is a stronger panel and as a result can span further distances. However, a thicker gauge will also cost you more. A 16 Gauge panel can be nearly double the thickness and the cost of a 22 gauge panel.


How To Tell What Gauge You Have?


If you aren’t sure what gauge of metal decking you have, you may find it difficult to tell the thickness by using a ruler. A common device used on a jobsite for an inspector to verify the gauge of the metal deck being used is a sheet metal gage measuring tool.



Gage is on one side Decimal equivalent in inches on other side



What Are The Common Metal Roof Deck Gauges?

Metal roof deck is manufactured in different profiles. Each profile will dictate what gauges are available to you. The gauges can also vary depending on the manufacturer. However on the West Coast you will typically find that for 1.5” Type B and 3” Type N, your options are: 22 Gauge, 20 Gauge, 18 Gauge and 16 Gauge.

1.5” Type B is a short to medium span panel and you will find that it is available in 22, 20, 18 & 16 gauge.

For 3” Type N, which is a deeper panel that can span longer distances, 22 Gauge is not a common gauge. The more common gauges for 3” Type N metal deck are 20, 18 and 16 gauge. Type N is used when a stronger panel is needed, which is why the heavier gauges are normally specified.


What Are The Common Metal Floor Deck Gauges?

Composite metal floor deck is is available in a few different styles. Types B-36 Formlok, W2-36 Formlok, W3-36 Formlok, N-24 Formlok, N3-32 Formlok are manufactured in: 22 Gauge, 20 Gauge, 18 Gauge and 16 Gauge.


What Are The Common Metal Form Deck Gauges?

Metal form deck comes in a few different profiles, all which vary by manufacturer. On the West Coast, Verco Decking has two types of non-composite form decks. They are types 9/16” Deep Type Shallow Vercor and 1 5/16” Deep Type Deep Vercor. Both types are manufactured in 26, 24, 22 and 20 Gauge.

For Type Shallow Vercor the most common gauge is 22 Gauge. For type Deep Vercor the most common gauge is 20 Gauge.


What Gauge Is Right For Your Job?

The right gauge for your job will depend on the type and application. The engineer will specify the correct gauge needed to fulfill the requirements for your deck. If you are in the bidding process and want to get a quick quote, be sure to bid the correct gauge. Bidding an incorrect gauge, can end up losing you money or costing you the job.

If you already have the job and are not sure how to figure which gauge, type, finish and/or quantity you need we can offer you a quote for our shop drawing package. Our shop drawings packages help take off some of the stress, we do the shop drawings and provide the metal decking for your job.

At Western Metal Deck we stock roof, floor and form deck. We carry it in the most common types and gauges available for each type. We can provide you with a quote and availability for the different types and gauges.

About Kathy Midence

Kathy Midence has worked for Western Metal Deck since 2009. She has worked with each department to better understand all aspects of the metal decking, metal roofing and metal siding industry.