modern composite deck with glass rails

How Much Weight Can a Deck Hold?

Published On: February 8th, 2024

If you are moving forward with the construction of a new deck, you might consider what is beneath the surface of your deck in addition to what kind of decking you will use.

How Much Weight Will Your New Deck Hold?

There is no “single” answer to the question of how much weight your deck can hold. There are many things to consider when making this calculation, and each of these things plays an important role in determining the amount of weight your deck can hold.

The weight a deck can hold depends on various factors, such as the materials used, the design of the deck, and the size and spacing of the supporting joists, beams, and footings. It’s important to consult with a structural engineer or a professional builder to determine the specific weight capacity of your deck based on these factors. A Municipal permit will go a long way in ensuring your deck will be built according to your local building code.


Whether your deck is constructed using wood or steel, the load that it will need to bear is called a live load. This will include the weight of people, furniture, and other movable items. The International Residential Code (IRC) recommends a minimum live load of 40 lbs per square foot for residential decks. Both wood and steel will be able to provide this when the substructure is built with this in mind. If wood is being used, the amount of weight it will hold can also depend on what type of wood is being used.

deck substructure


To meet the IRC code, spacing and spans are important. Local code will help in determining how many footings will be needed and how large your structure will need to be. For example, will a 2×8”, 2×10” or 2×12” substructure be used? For some projects, consulting with a structural engineer or a qualified professional is highly recommended. They can evaluate the specific conditions, loads, and requirements of the structure to determine the appropriate size and spacing of the substructure.


What you plan to use your deck for and what you plan to have on your deck is important to know. Typically, putting a large party of people on your deck will not be an issue. Hot tubs and outdoor kitchens may need to be considered. If you are using this deck for commercial purposes, how much weight your deck will hold may be in question.

deck bird eye view


The overall design of your deck and, indeed, its size will greatly affect the amount of weight your deck will hold. Keep this in mind when designing your deck. It is crucial to follow engineering and construction guidelines to ensure safety and structural integrity.

To determine the load-bearing capacity, it’s essential to consider both live loads, temporary or movable loads, like furniture and people, and dead loads, such as permanent or stationary loads, like the weight of the structure itself. Again, seeking professional advice for your specific situation is crucial to ensure the safety and stability of the sub-structure.

How much weight your deck will hold is not a guessing game but one of mathematics. Consult the professionals if there is any doubt.