Home improvement projects are on the rise in the U.S., which has created a huge demand for lumber. The increased demand for lumber has skyrocketed the cost of lumber by 30%—from $313 per 1,000 board feet to $400 by the end of 2014. With how much you're paying for lumber, it simply makes no sense to leave any spare materials lying around your property during the construction or renovation period. Instead, you should store unused lumber in climate-controlled self-storage units. Here are 4 crucial tips to follow.

Control the Relative Humidity Inside the Storage Unit

One of the main concerns of storing lumber is whether the storage unit is capable of maintaining a constant relative humidity. Even kiln-dried lumber is prone to absorbing excess moisture in the environment, so the relative humidity inside the storage unit will influence the moisture content of the wood. For example, with a relative humidity of 30%, the wood will reach 6% moisture content. If the relative humidity is increased to 50%, the moisture content increases to 9%.

Since the moisture content of the wood affects its stability and structure, you will need both a storage unit with climate-control features and an electronic relative humidity sensor. The sensor will monitor the room conditions and collect necessary data to confirm whether the wood is still in ideal condition for the construction work.

Seal the Ends of the Board with Wax

If the relative humidity in the storage unit is not always constant and fluctuates a tad bit every day, you can prevent the fluctuation from having an effect on the structural integrity of the wood by sealing the ends of the board with wax. If you do not like the waxed finish, you can always sand it off later on before you use in the construction project.

There are many different types of wax products you can choose from. Regardless of which one you use, you should air dry the lumber with a fan after the wax has been applied. This will ensure the wax dries properly.

Cover the Lumber Up

Even if you do believe that the self-storage units are clean, dry and properly ventilated, it doesn't hurt to take extra precautions by covering the lumber up with a plastic or cloth cover. You want to choose something that is breathable, so that air can circulate properly. This will prevent excess moisture from accumulating.

Covering the lumber up also reduces the risk of exposure to insects, pests and even microbes. Make sure the covers are able to adequately protect the lumber from the effects of sunlight and ultraviolet radiation.

Sticker Lumber Stacks to Prevent Moisture Accumulation

You don't want any lumber to be touching the ground, as this makes the lumber vulnerable to mold, mildew and a whole range of other problems. Use scrap lumber of medium-density fiberboards as stickers. Place the stickers underneath the lumber to prevent moisture from transmitting from the floor to the wood. Although stickers can cause discoloration, planing or sanding the wood later can easily remove the discoloration.

Use the same size stickers between each row of lumber to prevent bowing. In addition, you should always rotate the location of the lumber and the position of each board to alleviate the amount of pressure placed on the lumber at the very bottom layer.

Don't waste good materials and don't risk getting them stolen. Rent out a local climate-controlled self-storage unit, and you'll be set. In the proper environment and with proper conditions, lumber can be stored for long periods of time without warping or without having their structural integrity compromised.