“Why don’t you guys sand decks?”

So here’s the thing about sanding a deck…..

In most cases, your decking boards are only 19mm thick.

When those deck boards are exposed to the weather, they will expand, contract, and warp out of shape. You may not see it, but your deck is not perfectly level like the timber floors inside your home. 

Now imagine running a huge deck sander along this surface, trying to sand these boards that are all out of shape. First you would have to sand them down enough so that they are all even. Then, once they have been evened out, then you need to run up and down the boards to ensure they are evenly sanded and ready for stain. That’s at least 3 to 4 passes of sanding. 

How many mm do you think will need to be sanded back to ensure this process is done correctly? 

2mm? 3mm? If that deck is in really poor condition maybe 6mm?

Let’s average out and say we need to sand back 3mm. So now (assuming your boards are 19mm to begin with) you are left with 16mm. 

So each board is now 3mm skinnier. A deck with 16mm boards is definitely not stronger than one with 19mm boards. So why would you sand the deck? Now imagine if in a few years time you sand the deck again. Compromising its strength once again. The boards could have only 13mm left. While some decks may boast thicker boards, up to 25mm, the potential reduction in thickness remains a concern, and frankly almost all decks we work with have 19mm boards.

While most agree that any type of sanding “promotes” stain/paint adhering to the surface, often times its the exact opposite. Often when a deck is sanded, the surface becomes to smooth for the stain to absorb into the timber. Frequently I hear of people that have “perfectly” sanded their deck before applying decking stain. They completed what they thought was the perfect prep work. Only to have the stain peeling away from the surface 3 months later. 

In conclusion, the decision to sand a deck comes down to the current condition of the deck. If the condition of the deck is bad enough and the only way to bring it back to life is by sanding it, we recommend another company that focuses on sanding. In most cases however, a professional clean + re stain is what the timber truly needs to be brought back to life. 

We provide customers with a maintenance plan, including periodic staining to minimise the need for extensive sanding.