Engineered Floor Joist vs. 2×10

In the past, architects, builders, and other people involved in building a house had limited options for floor framing, but now there are engineered floor-framing options such as floor trusses and floor joists. Before the invention of engineered floor joists, dimensional lumber such as 2×8, 2×10, and 2×12 were the go-to choices for floor-framing. One of the downsides of these dimensional lumbers (the 2×10, 2×12, etc.) is that they sometimes require bearing walls or supporting beams, and these could limit design and building possibilities.

Unlike dimensional lumber, engineered floor joists create accessible open spaces for builders and designers because they can span greater lengths. 2×10 joists are made of 2×10 wood boards that support whatever structure you are building (in this case, floors). Admittedly, engineered floor joists (also known as I-joists because they are made in the form of an “I”) have revolutionized certain aspects of building. They have added even more stability and strength to what dimensional lumber brought to the table.

If appropriately blocked, engineered floor joists cover more length between bearing points than dimensional 2×10 lumber. Because of their “I” shape, engineered floor joists weigh up to 60 percent less than dimensional lumber joists (such as 2×8, 2×10, and 2×12) and are easier to handle because of their relatively lightweight. Engineered floor joists are considered safer and better for the environment than 2×10 joists because they require 35 to 60 percent less wood and can be made from smaller, faster-growing trees.

Engineered Floor Joist vs 2×10

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 Engineered Floor Joists2×10 Joists
Weight LimitEngineered floor joists have a reasonable weight limit, i.e., a limit to how much weight they can bear without damage. Engineered floor joists can carry 20 pounds of dead load options per square foot, although the average building code requires and/or recommends a minimum dead load of 10 pounds per square foot. Engineered floor joists can bear live loads at a minimum of 40 pounds per square foot, but typical building codes require a minimum live load option of 50 pounds per square foot. But to successfully carry that much weight, the joists’ span should be limited to 11 feet and 11 inches to support heavier weight better.Like engineered floor joists, 2×10 joists can hold up to 40 pounds per square foot of live load and at least 10 pounds per square foot of dead load options. A 2×10 floor joist at 16”spacing can bear up to 53 pounds per lineal foot (PLF), and this translates to a 318-pound single point load at the center of the joist.
CostAlthough prices are not uniform across distributors and stores, engineered floor joists are often a lot cheaper than 2×10 joists. On average, engineered floor joists cost $2.50 per square foot. Because of its low price, residents and builders sometimes favor the use of engineered floor joists over 2×10 joists.Although they have saturated the market for decades, even before engineered floor joists were invented and introduced,the cost of 2×10 joists is several times more than that of engineered joists. The average price of 2×10 joists is $13 per square foot. Despite the price, and perhaps because it has been in the market for longer, many still use and trust 2×10 joists over engineered floor joists.

Differences Between Engineered Floor Joist and 2×10


Engineered floor joists are available in lengths of 16 feet to 48 feet (the lengths of engineered floor joists start fromm16 feet and increase in increments of 2 feet). You can find engineered floor joists at different lengths, but the longest you can find 2×10 joists at stores is 16 feet. There are 2×10 joists as long as 20 to 24 feet, but they are not available in most stores, so you will probably have to visit a local lumber yard and pay a lot of money if you want lengths more than 16 feet.

The widths of engineered floor joists depend on the size of lumber used for the flanges, but they may be 2 ½ or 3 ½ inches wide.Engineered floor joists’ depths often mimic dimensional lumbers used for joists; depths may range from 9 ½ to 16 inches in residential buildings, and depths of 48 inches are possible in commercial buildings or usage. The webs of engineered floor joists are often 3/8 inches thick, but they are occasionally 7/16 inches thick.

Fire Safety

2×10 joists and engineered floor joists are made of wood, so they are both susceptible to damage by fire, but engineered floor joists are more of a fire hazard due to lack of mass (in comparison to 2×10 joists). The webs of engineered floor joists are made of OSB (oriented strand board) and connect the top and bottom flanges into the “I” shape, and they could collapse if they catch fire.

This collapse poses a severe hazard to residentsandfirefighters who may enter the residence to extinguish a fire. The possibility of the collapse of engineered floor joists does not mean that they are more likely to catch fire, nor does it mean that 2×10 joists cannot collapse if there is a fire.

Similarities Between Engineered Floor Joist and 2×10


Engineered floor joists and 2×10 are adjustable on the building site. Builders can quickly make corrections to the length of the joists to fit the site engineer’s requirements. The adjustability of engineered floor joists and 2×10 is a great advantage when there are inconsistent distances between bearing points.


Engineered floor joists and 2×10 have advantages and disadvantages to consider in determining which is better. For example, a disadvantage of engineered floor joists is that water can damage them, so you may only use them indoors. Also, some builders, plumbers, electricians, and other contractors who may work in your home close to your engineered floor joists, do not have experience working with engineered floor joists. A disadvantage of 2×10 joists is that they are heavier than and not as stiff or sturdy as engineered floor joints. If you are choosing between engineered floor joints and 2×10 joists for your home, consider your budget and match it with the option that is within what your pocket can manage. You should also consider the scale of your project; is it a small-scale project or a medium to a large-scale project? If it is a small-scale project, there are few differences between 2×10 and engineered floor joists in terms of installation. If it is a larger project, engineered floor joists may be better because they reduce the time that goes into setup and installation.

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