Can You Pour Concrete Over Wood Decking?

In short, yes you can, but would you want to, given the skills required to perform this type of work, the potential labour costs, notwithstanding the risk of structural failure to the area later up the line.

A concrete patio is one of the many options for outdoor flooring. Many prefer it over other choices due to its cheap cost and low upkeep. Despite being one of the most popular outdoor flooring options. Mainly due to its affordable price, most woods used to build decking are high-maintenance and costly over time. Because of this, many homeowners are looking to replace it with something else. If you have an existing wooden decking area, you may have considered pouring concrete over it. But the question is, can you do it? What are the things you should know before doing it? How should you do it?

Pouring Concrete Over Wood Decking?

Pouring concrete over your exiting indoor flooring may seem far-fetched. However, it’s a common construction practice. These common construction practises are mainly concrete overlays which is different to pouring concrete over wood. Overlaying concrete over existing concrete floors can hide damage and enhance its appearance. It also works on other surfaces, such as cracked concrete or other non-wood floorings. Because concrete is easier to maintain, customisable, and cheap, many homeowners choose concrete to replace their outdoor flooring with it.

While overlays are a common construction practice, there are a few things up for consideration if you plan to do a concrete overlay. For instance, there are several advantages and disadvantages of a concrete patio.

Things You Should Know Before Doing a Concrete Overlay

A concrete patio is significantly less demanding to maintain than most wooden decks. It doesn’t need yearly treatments, such as staining and painting. while not aesthetically pleasing at first, you can customise a concrete patio with various patterns, finishes, and styles. And during the summer days, it’s considerably cooler to touch than other flooring surfaces.

While there may be several advantages to concrete patios, you will need to be aware of their disadvantages. For instance, concrete is susceptible to staining, cracking, and freezing compared to decking, they also don’t add as much value to your property. While cheap, adding features, designs, and stamping on the concrete can be expensive.

Lastly, there may be instances where pouring concrete over flooring is not advisable. You will need to check the condition of the existing wood decking. if it’s too worn down, it won’t likely be able to support the concrete overlay. if that’s the case, you may save more time, money, and effort by removing the decking first and then pouring concrete.

How to Pour Concrete Over Wood Decking

The complexity of pouring concrete over wood decking depends on many factors. While concrete overlays are a common repair practice, they’re different to pouring concrete over a wooden deck. Concrete overlays, as mentioned are used to repair or enhance existing indoor concrete floors with a thin layer of concrete over the top. This is very different to pouring concrete over an existing wooden outdoor deck.

If you do decide to pour concrete over a wooden deck, in our opinion, this is definitely not recommended since there are many factors to take into consideration.

Firstly, you are using and applying two different materials together. Pouring concrete in with wood since both materials absorb moisture and expand at different rates and at different temperatures, therefore this is already a risky practice. The next step, if you still decide to proceed, is similar to a concrete overlay. The wood will need to be sealed including any gaps or divots in the wood. You will also need to treat, seal or remove other existing materials such as metal screws and fasteners that is holding the existing wooden deck in place.

Next stage is preparation, this is a key important aspect for pouring the concrete into the existing wooden decking area. Prepare and seal all gaps and the sides of any exposed area of the wooden decking area. Due diligence should be taken during the preparation stage to ensure the correct type of industry approved sealants are being used. This type of project requires the use of skilled tradesman with years of experience to carry out and perform this type of specialised work. If you don’t have the required skills we recommend hiring a professional to perform the work or remove the existing wooden decking area before proceeding. Many DIY’ers begin this type of work with the goal of saving on costs, however the materials maybe cheap but hiring a professional to complete the project won’t be cheap for their labour.

The main consideration, before deciding if the project is worth proceeding with, is the current condition of the existing wooden decking area. This is the most important reason not to pour concrete over wood. Concrete is extremely heavy, if the frame of your existing wooden decking is old and has potentially begun to rot. Even, if rot has not yet started, years of use will definitely have affected the structural integrity of your frame and base. Wood is known to weakening over time and on this basis we definitely recommend against pouring concrete over existing wooden decking, as it has a very high degree that the wooden structure and base will fail leading to further complications further up the line. 

Conclusion

Pouring concrete over an existing wooden decking may seem a cost effective solution to begin with, but the complexity to this for the average customer may create future issues, increased labour and possible remove of the the concrete and wood at a later stage if not do correctly. Furthermore, even done correctly this method still has complications, as the strength of an existing deck and frame will be greatly weaker when compared to a newly installed frame, meaning this will most likely be a short term fix, which is labour intensive.