Floor Joists vs. Floor Trusses

If you think of the words “well-built”, what words do you think of?  I think of the words “stable”, “strong”, and “high-quality.”  These are words you definately want to hear when you are discussing the floor of your home. No one wants a floor that sags or bounces. To avoid that, there are a couple of common ways a contractor builds a floor.

The first way is with floor joists.  Joists are a series of horizontal timbers, spanning a space from wall to wall.  The floor in my home was constructed with floor joists.  Here is a picture:

My husband and I chose this system because we believed it to be the most cost-effective way to build our floor.  However, after building many homes, Dave has found out that floor trusses come out to be very close in price.  In some cases, they can even end up costing the homeowner less than floor joists.

What is a floor truss? It is a timber with a geometric design, engineered specifically for your home.  It is fastened with metal connector plates to form a structure that supports a given load (dead load: cabinets, tile, etc., and live load: everyone that walks on it).  Here is a picture of floor trusses in a home my husband is building right now:

Initially, floor trusses cost more, if you are comparing material costs alone.  But floor trusses catch up in cost or even surpass savings on joists in these areas:

1)  You avoid many labor costs.  Floor joists only have a certain distance they span before they require a heftier joist (which gets expensive really fast), or they require a load-bearing beam or wall to be built.  This requires more time, and we all know what that means: more money.  Floor trusses are designed every time to span whatever distance you want by an engineer.  This can be a great advantage when you specifically want a wide-open floor plan.

2)  Sub contractors can install floor trusses much faster, again, requiring less labor costs.  Walls can be eliminated, and there is a greater nailing area for them to hit.  Joists have only a 1 1/2 inch area to hit, and trusses have an area of 3 1/2 inches.

3)  Floor joists have to be drilled through and worked around when it is time to install plumbing, electricity, and heating and cooling systems.  Code requires that joists can only be drilled in in specific spots, or it will compromise the integrity of the floor.  Duct work and plumbing might have to take longer routes and be more complicated than they otherwise could have been.  With floor trusses, the spacing is already there.  These things are installed with ease, and a builder doesn’t have to worry about weakening the floor by drilling.  And as a decorator, I must say that duct work coming down below the ceiling level in the basement isn’t the best…nothing can be done about the look, and placing lighting where you need it becomes a problem.

Both systems are effective, but next time you have the chance to do a new floor or fix an old one, floor trusses might be an excellent option.

If you have any questions about your home, send them to us via the contact page.  We’re here to help!



  1. says

    Hi, Tawna,
    I stumbled by this post today & think it’s great! My husband is also a carpenter / contractor. I love to see people sharing useful & informative information.
    My husband uses engineered floor trusses all the time, to span greater distance without supporting walls or beams. In fact, we’re just adding onto our house right now, and installed some a couple of days ago. ? I was blogging about that project this evening.

  2. george says

    I would like to know you think would be the better to span 35′ and why. I am thinking of building a different style home and I have a lot of questions, so if you could answer this question for me that would be great and a price range also. I will thank you now.

    thanks george

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