If you’re doing anything significant with your flooring at any point, there’s a high chance that you’ll come across the term “floor trusses,” and it’s one that leaves a lot of people stumped. Joists are much more commonly mentioned and you probably feel comfortable with those – but what about trusses?
It’s important to know what trusses are if you’re dealing with a floor that bears a lot of weight, although they are often only used in commercial buildings. If you have trusses in your home, understanding how they work and what they are becomes critical.
What are floor trusses? Floor trusses are made up of vertical and diagonal braces, assembled together to form a strong, supportive structure that has a high load-bearing capacity and does not need intermittent support. By contrast, joists are horizontal structures that are installed between beams. They spread the load, but need intermittent support.
What is a Floor Truss?
A floor truss is a means of supporting a floor that needs to be able to bear a lot of weight. It is made up of triangles. Trusses are useful in certain situations, particularly in commercial buildings, where there’s a higher chance of the floor needing to bear a lot of weight. They prevent the floor from bouncing as much, and they can be run over very large spans.
They have quite a lot of advantages over joist systems. Firstly, there is no need to build interior supports if you use trusses, so it’s easier to alter the interior walls. They are cut very exactly, reducing the amount of waste associated with building,
They also require fewer resources, and they make it noticeably easier to run electrics and plumbing through the building, as well as HVAC.
These benefits make the overall building time faster, and cut back on costs in terms of both labor and materials. However, you do need specialist timber, which is treated in a controlled environment to ensure it is strong enough. Construction-grade wood must be used, and you need 2×3 or 2×4.
A further advantage of trusses is that they are less likely to warp and shrink over the years. This makes floors built on trusses last better, and may ensure that they stay level and don’t suffer from any sagging.
Are Floor Trusses Expensive?
One of the drawbacks of floor trusses is that they sometimes cost more to install upfront. This is because they require specifically treated lumber, not just any old wood – and they also offer better quality, which attracts people who are interested in longevity. However, because of the reduced labor and material costs, they may sometimes work out cheaper.
It’s important to get quotes for both trusses and joists from several different firms if you are thinking of installing trusses in a building. Some will cost more than others.
To give you a guideline for the price of trusses, a 28-foot-long truss might be around $8 per foot, although this will depend on other factors, and some range as high as $10 per foot. The price will vary according to the type of wood and its depth and width, as well as the supplier you choose.
It’s always a good idea to compare prices across several suppliers to make sure you are getting the best possible deal with your trusses. If you’re covering a large area, a few dollars per foot will make a massive difference to the price of your overall project.
Why Do Trusses Not Need Additional Support?
Trusses are self-supporting because they use a triangle system. The vertical pieces of wood support each other and the horizontal ones, and the overall system is very stable. However, floor trusses are heavier than joists because they have their support system built in across their length, whereas joists will only need occasional supports.
Are There Different Kinds of Trusses?
Although there are many variations, there are only two basic designs that are used for floor trusses. These are known as the Warren truss and the Pratt truss. The Warren truss takes the shape of a W, while the Pratt truss takes the shape of an N. Both are excellent for supporting the floor above.
In the Warren truss, the supports run diagonally up and down, while in the Pratt truss, one support stands vertical, while the next is diagonal. These are the main kinds of truss designs you will see.
How Do You Build a Truss?
In general, trusses need to be built in climate-controlled factories by skilled engineers and carpenters. They are not something that you will be building yourself at home, no matter how tempting this might seem. Trusses are complicated and incredibly sturdy, and they need to be built by experts.
Trusses require angle cutting for the components that make up the webbing, and it will be necessary to fasten the joints with steel in most cases. Other machinery needed for creating the trusses includes things like automated rollers, and you are therefore not going to be able to recreate this at home.
Although the basic design of the truss might look achievable to you, you should be aware that you cannot build these yourself. A truss must be very precisely engineered to fit the specific span it will cover, and the connector plates must be pressed into place with machinery.
If either of these requirements is not fulfilled, there’s a risk that your floor truss will not be strong enough to support the structure. The resulting damage could be extremely dangerous to people using the building, and may cost enormous amounts of money to fix. You should not try to build trusses yourself, even if you are a skilled carpenter.
Final Thoughts
Floor trusses are an alternative to floor joists, and they are a great option if you need to add very strong structural support to a building. They offer quite a few advantages, including more room for running plumbing, cables, and vents, but you’ll need to check their cost, as trusses aren’t something you can DIY.
