How to Use a Water Level to Level a New Deck

A water level is an easy and inexpensive way to level a deck.


A water level is a valuable tool you can make at home. When you are building a new deck, a water level can help ensure you have a level surface, no matter how large you build your deck. A deck that isn't level can lead to structural issues and water damage, both of which present a safety risk.

Make or Buy a Water Level

To make your own water level, you need a long clear tube and some water. When the tube is filled with water, the water at both ends of the tube naturally settles at the same level. You can add food coloring to dye the water and make it easier to see where the level settles. Electronic water levels sold in home improvement stores work in the same manner, but the machine beeps when the level is reached. This can be useful if you are working alone and are at a distance from your starting point.

Determine the Deck Height

Before you can level your deck, you have to determine at what height you want it to be positioned. Even if you want to build the deck right on the ground, the height would be the width of the wood you intend to use for the frame. Using a level helps you make adjustments based on the fluctuations in the ground. The height you choose should depend on the layout of your yard, the intended purpose for the deck, and whether you want to attach it to your house or a pool.

Mark the Level Points

Begin constructing the deck by a marker, such as your back door or the edge of your pool. Use this as the starting point to determine the height for the frame as you go along. Make a mark on the frame at the height you wish it to be, then attach one end of the water level so the edge of the water is even with the mark. Use the other end of the level to mark the same height at other points along the frame. Hold the other end of the level against the frame, and once the water stops moving, mark the place where it settles. This will be level with the starting point.


There are many things that could cause the water level to give an incorrect reading. Air bubbles in the line can cause the water to rise higher than the level. Adding water to the line can cause changes in water density because of the opposing temperatures, which can cause a raising or lowering of the water line. Double-check your work as you go along -- using a piece of board and a beam level -- and if you notice any inconsistencies, empty the water level and refill it with new water. Use it again to level the deck anew.

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