Ask the Builder

The Basics for a Wooden Shed That Will Last

Framing lumber is sufficient for the walls of a shed, but treated lumber is best for the floor to resist rot from leaks.
Framing lumber is sufficient for the walls of a shed, but treated lumber is best for the floor to resist rot from leaks. (Photo By Tim Carter -- Tribune Media Services)

By Tim Carter
Saturday, November 3, 2007

Q: DEAR TIM: As I looked for leaf-raking tools in the debris field formally known as my garage, I realized that I need a storage shed. I looked at outdoor storage sheds at dealers and home centers, but I want to build my own. Are wood sheds the way to go? -- Brian F., Lancaster, Pa.

A: DEAR BRIAN: Building a shed involves hundreds of steps, but some of the most important are in simply planning it. For example, you may want to build a combination storage shed and garden shed. I did this two years ago, and it has turned out to be a huge success with my wife.

One of the first steps in your shed project should be a visit to local government officials. You need to know how zoning laws deal with sheds, as well as to familiarize yourself with local building codes. For example, where I live, the building department is not concerned with sheds that are less than a certain square footage. You may discover that you do not need a building permit.

After you have learned what you need to do to build the shed in compliance with the law, decide whether the shed will have a wood floor or a concrete slab. I have built sheds both ways, and I think one with a wood floor works well if you use the right materials. If you want your storage shed to be problem-free for years, make sure it has a great foundation that will not move. I prefer working with wood because it is affordable and easy to cut, move and erect.

Structures built in climates where the ground freezes must be protected from frost heave. When soil freezes, the water in the soil expands. This can lift the soil dramatically.

There are different ways to build a frost-protected foundation, including full-length poured-concrete footers that extend below the frost depth and round concrete pads that support treated-lumber posts. I like using the wood-post method, as it resembles a traditional wood deck. For a simple outdoor shed, you may only have to dig four 16-inch-diameter holes for the entire foundation.

The wood-floor system should be made with treated lumber that resists rot and wood-destroying insects. I also use treated-lumber plywood for the floor of my storage sheds. In this way, any water that drips from tractors, tools or other things will not damage the flooring structure.

When you frame your shed walls, use ordinary framing lumber but always use a treated-lumber bottom plate. In case water does get into the shed, the treated-lumber bottom wall plate helps resist wood rot. Be sure to use plywood or oriented strand board at all of the corners of the shed. This makes the walls strong enough to resist racking forces caused by roof load and wind.

You can buy prefabricated roof trusses, but cutting simple rafters is not that hard. If your budget is tight, you will probably discover that framing the roof without trusses is the better alternative. You will have to learn how to cut simple rafters.

Cover the exterior walls and roof with overlapping asphalt felt paper before you apply siding or shingles. The felt paper will prevent any wood rot in case a leak develops over time.

After you decide on doors to get into and out of your storage shed, consider smaller overhead garage doors. Everyone who sees the six-foot-wide metal overhead garage door in my garden shed marvels at it. It provides ample room to get my garden tractor in and out, is lightweight and easy to open and close, and is attractive. It only took me 90 minutes to install this gorgeous overhead shed door.

Tim Carter can be contacted via his Web site,

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