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What Is Q Decking? [Definition, Types, & Alternates]
Robert Rubio

By: Robert Rubio on November 6th, 2020

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What Is Q Decking? [Definition, Types, & Alternates]

Metal Deck

Q decking is a term we continue to hear from customers year after year, which comes as a surprise since Q deck hasn’t been manufactured in over 20 years. So why then do we keep getting requests for Q deck if it no longer exists?

One of the reasons we continue to hear the term Q deck is most likely the very same reason you happened to find this article. Contractors and builders continue to use the term Q deck to simply mean metal decking.

This stems from the popularity of Q decking back when it was still being manufactured. It was a popular series of composite metal floor decking that was often specified on jobs. So when a contractor or builder wanted to use composite metal floor decking on their building, they normally wanted Q deck.

So what does all of this mean for you?

Well the most important thing that you need to understand about Q deck is that Q deck is no longer manufactured by any existing company. Q deck has not been manufactured since the 1990’s.

Western Metal Deck has been stocking and supplying all kinds of metal decking for over 20 years. As a metal decking supplier, we find that we continuously get requests for Q deck or Robertson’s decking from customers who aren’t aware that this product no longer exists.

If you do happen to be bidding or have a job where you have a request for Q deck then we want to make sure you understand what Q deck was and help you find some current alternatives.

In order to help you with your metal decking job we will go over the following:

  • Who Made Q Deck?
  • What Is Q Deck?
  • Types Of Q Deck?
  • Alternates For Types 3”-QL99 & 2”-QL99?

Who Made Q Deck?

Q decking was manufactured by HH Robertson Company. HH Robertson was a company that manufactured metal roof and floor decking. Back in the 1960’s they invented a composite metal floor decking by adding an embossment pattern to the metal decking during the roll forming process. They named this type of metal decking Quick Lock or the abbreviated name QL.

What Is Q Deck?

Quik Lock or Q deck was a type of composite metal floor decking that came in different profiles and gauges. It was created by HH Robertson Company. The QL abbreviation stood for Quick Lock, which is what they used to refer to the embossed metal floor decking.

Prior to the invention of Q deck, metal decking was smooth, with no embossment pattern. It served as a pan decking or form decking when concrete was poured on top.

When HH Robertson manufactured metal decking with embossments on the ribs of the metal decking, it allowed for a composite reaction to take place between the cured concrete and the embossed metal floor decking.

Once the structural concrete, which was poured over the Q deck, cured, it bonded to the embossment patterns rolled into the Q deck. This bonding between the Q deck and the concrete created a composite action. “What do you mean by composite action”, you might be asking yourself? Well, when two materials bond together in a composite action, the composite strength of the items that are bonded together is greater than the sum of their individual strengths.

Q deck was the first metal decking to create a composite reaction. Nowadays composite metal floor decking is manufactured by all major metal decking manufacturers.

Read about composite metal decking


Types Of Q Decking

When Q deck was available there were two main types that were specified on construction projects. Types 3”-QL99 and 2”-QL99 were the most common types of composite metal floor decking.

Type 3”-QL99


Type 3”-QL99 was a 3” deep non-cellular composite metal floor decking. The panel was 2 feet or 3 feet wide and the sidelaps had to be stitch welded together.



Type 2”-QL99


Type 2”-QL99 was a 2” deep non-cellular composite metal floor decking. The panel was 2 feet or 3 feet wide and the sidelaps had to be stitch welded together.



Alternates For Types 3”-QL99 & 2”-QL99

While an exact match to Q deck no longer exists, there are modern day types that are similar and available. Type W deck is the type of composite metal decking panel which most closely resembles both types of QL deck. W decking comes in a 2” deep and 3” deep panel.

W3-36 FormLok

w3-36-formlok-dimA modern style of type 3”-QL99 composite floor decking is called type W3-36 FormLok composite decking. This panel is 3” deep, 36” wide, the sidelaps have a male leg and female leg. The sidelaps can be connected with a button punch tool, punchlok tool, stitch screw, or seam weld.


W2-36 FormLok

w2-36-formlok-dimA modern style of Type 2”-QL99 composite metal floor deck is called type W2-36 FormLok composite decking. The panel is 2” deep, 36” wide and has a male female side lap. The sidelaps are connected by either: button punch tool, punchlok tool, stitch screw, or seam weld.



What To Do If Your Job Specifies Q Deck

If you have a job specifying Q deck, your first step would be to notify the general contractor, engineer, and or the architect that this product no longer exists. If you are trying to find an alternative option to present, then we suggest contacting a sales rep. Our sales reps have years of experience with metal decking and can assist you on your next metal decking job. 

In very few cases you may get resistance while trying to get a modern metal floor deck panel approved. If this happens you must explain to your customer that it is impossible to get Q deck anymore and that their job must be converted to a modern type of decking and will not be able to proceed until that happens. You may want to refer them to this blog and hopefully things will then be able to move forward. 


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About Robert Rubio

Robert Rubio is the President of Western Deck & Steel Erection. He has been in the steel construction industry since 1970 and is a Journeyman Local 433 Iron Worker.