How to Choose the Right Floor Framing System

How to Choose the Right Floor Framing System - A Comparison Guide to North American’s most popular floor joist options - iSPAN Systems - banner

A Comparison Guide to North American’s most popular floor joist options

The construction industry is constantly improving itself, finding new ways to work smarter, faster and better than ever before. To be innovative, every construction component needs to focus on constant innovation. Even floor joists! They are key structural components that must be practical for engineers, contractors and end users, and as such choosing which joist material is best for your project is a crucial consideration.

In this comparison article, we will briefly discuss the common flooring joists to see which comes out ahead.

First, let’s clarify something. What is a joist? It’s the long structural element, often made of wood or steel, that holds up a floor. Joists carry their loads to beams or walls.

And while we have your attention, a frequent question regarding joists is, “How far apart are ceiling joists?” In normal circumstances, floor and ceiling joists are spaced 16” apart from the centre of one joist to the centre of the net.

Now, let’s delve into your joist options to see which comes out ahead.

Dimensional Lumber Joist

Dimensional lumber’s lightweight size and material, as well as its familiarity among everyone in the industry, makes it attractive for a wide variety of projects that require joists: residential, multi-storey and commercial developments. Even skyscrapers can be constructed using dimensional lumber.

Unfortunately, rarely do things go perfectly when you choose dimensional lumber as your structure’s joist. Since lumber comes from plants, no two pieces are alike, which as you know can result in imperfections that slow down construction. Each piece must be cut to size onsite, which also requires a large amount of space, garbage and wasted time. The result is a product that can deteriorate with water leaks, be infested with rodents/insects and make floors that irritatingly squeak.

Prefabricated Wood I-Joist

The “I” shape of this option helps to create a strong and relatively inexpensive joist solution that can span up to 20 m (66 ft.).

It is made of wood, which as we know is imperfect, but the plywood vertical section glued with the solid dimensional lumber gives strength far superior to dimensional lumber on its own. The mighty I-joist also gives construction crews the ability to cut holes through the plywood where access is required for heating, plumbing and electrical.

Open-Web Wood Truss

This equally strong support option can be used for roofs or floors, built with large gaps to allow the easy insertion of plumbing, heating and electrical lines. It is lightweight, which can be safer and easier for construction crews, although design must take place prior to delivery to your job site.

Made of wood, open-web wood trusses can still shrink and expand, and be negatively affected by water, rodents and insects. Considering recent lumber shortages and price inflations, wood trusses can often have prices similar to steel.

Cold-Formed Steel Joist

Joists made of cold-formed steel are lighter than their wooden counterparts, and very strong. Since it is made of steel – a non-compostable material – the joist will not break down when invasive elements come in contact with it. Like open-web wood trusses, cold-formed-steel joists help to reduce and even eliminate bulkheads, saving space for any type of structure.

Each cold-formed-steel joist is designed prior to installation, to ensure a proper fit, with options available to allow for small adjustments onsite if needed. Since each component is designed and cut prior to arriving onsite, construction speed is often accelerated compared to some wood options.

Which Flooring System Joist is Best for My Structure?

We believe that the planning part of any project is the most important, as it makes for a seamless construction experience. For that reason, as well as the long-term viability of steel, we believe that cold-formed-steel joists can make for a superior designing/construction/usability experience that’s unmatched by any type of wood joist option. Be sure to ask your cold-formed-steel joist supplier if they use Building Information Modelling, which significantly reduces site issues.

To learn more about iSPAN System’s proprietary cold-formed-steel TotalJoist, and the single-source supplier’s many benefits for developers, architects, general contractors and tenants, contact iSPAN director of sales Dwayne Schaus at dwaynes@ispansystems.com or call 1-855-804-7726.


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For projects in the United States, reach out to one of our Authorized Dealers.