How much weight can a wood floor support?

 In Floor joists

The weight that can be supported by a wood floor is an important factor to consider before undertaking various types of renovation work in a house, especially when installing new flooring or a heavy element (a freestanding bathtub, for example). In fact, depending on the load-bearing capacity of the wood floor, it may be necessary to reinforce it before having the work done.

Naturally, many things can influence the load bearing capacity of a floor built with wood joists. In this article, find out how to determine how much weight a wood floor can support based on its characteristics.

Calculate the load bearing capacity of a floor using joist tables

When building a floor, the joist tables are used to determine the dimensions of the center distances (space between each joist) as well as the span of the wood beams (total span of the joists) to choose according to the operating load of the rooms.

Joist tables can also be useful in determining the maximum load a floor can support.

Here is an example of a joist table:


However, you should know that there are a large number of different joist charts available, so make sure you use the one that best suits the floor configuration you are considering. This is because the numbers in an abacus will change depending on the permanent and temporary loads and the type of floor joists.

Characteristics that can influence the allowable load of a wood floor

As mentioned above, it is crucial to use a joist chart that is perfectly suited to the existing floor in order to have a precise idea of the load it can support.

For this purpose, it is helpful to know:

  • The type of floor joist used (2×8, I-joists, prefabricated floor joists, open-web truss systems, etc.).
  • How the joists are fastened (with web stiffeners, with reinforcements, etc.).
  • Wood species of the joists (softwood, hardwood, use of glulam, etc.).
  • The span of the part (the distance between two supports, i.e. the length of the joist)
  • Joist spacing (the distance between each joist)
  • Dead loads (loads that do not vary over time, such as the weight per unit area of the floor covering or ceiling under the floor)
  • Operating expenses: expenses that vary over time.

In short, the more details about the floor construction you have, the more accurate the results will be. Conversely, determining the weight that a floor’s wood frame can support will be very difficult if you don’t know anything about its design.

UsiHome helps you to build solid floors and more

In conclusion, the first step to knowing how much weight a wood floor can support is knowing how it is designed. Once all the important information is available, the load-bearing capacity of the floor in question can be determined.

One thing that is certain is that expert advice should always be sought before undertaking any renovation work to ensure that the building structure and floors are strong enough.

That said, if you’re looking for high-performance floor joists or floor joists that make it easy to install building mechanical components, you can rely on UsiHome structural wood products. They are designed in Quebec, comply with the National Building Code and can be delivered to your site when you need them.

Usihome has extensive expertise in prefabricated wood structures. You can count on us for all your roof trusses, prefabricated walls and floor joists. Contact one of our representatives to find out more about our services and to discuss your project.

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