Composite Decking Substructure

Composite Decking Substructure


Whether you are building a wooden deck or a composite one from Deckorum, your deck must have a substructure. The materials you use to build your composite deck substructure are crucial.

For starters, your deck needs to have a solid and long-term foundation. You will then need a frame for your deck which will then become the deck’s substructure.

Though you will probably hire an expert to help you with the substructure it helps to know as much as you can about the various framing options.

The following are the common materials for framing a composite deck substructure:


Wooden joists to be specific, pressure-treated softwood joists, are prevalently used in decking substructures. They are cheaper than steel and composite materials.

When laid properly, timber framing will give you between fifteen and twenty years of great service. In some cases, the foundation may last longer.

The durability of a timber frame in a deck substructure will depend on other factors such as the deck’s location and the environmental conditions. Wood absorbs water so if you are building your deck somewhere that regularly gets wet, it will make a very difficult job for the builders.

Mistakes will start to happen during construction that will have serious repercussions later. An example of such mistakes is the joists not being parallel which weaken as time passes.

Timber joists are prone to twisting and rotting if they are constantly wet. The vast majority of timber substructures can withstand the elements well if constructed properly but some conditions make them more susceptible to deterioration such as a garden or a yard that drains water to the deck.


Steel is one of the hardest materials known to man. With a steel frame for your composite deck, you can be assured that it will never rot or sag in any way.

Steel framing also has other benefits one of them being a higher fire safety rating. The greater the distances between steel joists and bearers, the longer the lifespan of your deck.

Steel substructures also have their faults. One of them is the initial cost which makes it the most expensive deck substructure material.

Steel is heavy and transportation is quite cumbersome and it takes a long time to install as well. You also need to apply treatment to ensure it doesn’t rust.

Composite Materials

Composite materials are typically made of wood and plastic and offer the best of both products. One of the advantages of using composite material for a substructure is that it is easy to work with which means a shorter installation time than with the two materials above.

Read more; Tips To Know If The Wood Furniture Is Worth Refinishing

Moreover, composite materials will not warp, rust or rot. The combination of wood plastic means that composite materials are essentially waterproof.

Another advantage of using composite materials for framing the deck substructure is that it is quite affordable. It may be slightly more expensive than wood but it is nowhere near steel.

The major downside is that composite materials are not as strong as timber of steel which you will have to account for during construction of the substructure.

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