It is difficult to beat concrete as a versatile, durable foundation construction material. It should then come as no surprise that it is often chosen for the foundations of residential storage and garden shed projects. Concrete work is not overly complicated and well within the capabilities of most do-it-yourself types.
Concrete slab foundations are a popular choice for home building projects but sometime concrete pier foundations can be a better option. These foundations are sturdy but require less concrete and less time spent on excavation. Concrete pier foundations also eliminate the finishing work required by a broad expanse of poured concrete.
Savings in both time and money are the primary advantages of this type of foundation. However, they can also be useful when the selected site of an outbuilding happens to be near a tree where excavation for a slab would be complicated by the presence of tree roots and where real damage might be done to a valued tree.
Concrete Pier Foundation Construction Preparation
Laying out a squared foundation using batter boards and Mason’s string is the first step in concrete pier foundation building. Guide to Foundation Construction: Tips for Laying Out Squared Building Foundations is a ready resource for those unfamiliar with foundation building or those who just need a refresher.
Once the foundation outline has been verified as square, the footings for the concrete piers can be marked. The corner pier footings can be dug with a post hole digger or power auger with the holes centered on the corner stakes. For rectangular foundations large enough to require intermediate concrete piers along the long sides, the footings can be sighted along the Mason’s string outline using a plumb bob to mark them.
Footing holes need to be slightly larger in diameter than the size of the tubular cardboard pier forms that will be used which come in several different sizes. Holes should be dug below the frost line and in accordance with any local building code requirements. The footings should be finished by adding about 4 inches of compacted gravel to the bottom in the interest of good drainage.
Setting the Foundation Piers Forms
Given that construction sites are rarely perfectly level, it is difficult to simply cut all the pier forms to the same length. The easiest method is to cut them to an approximate length where they will extend to the bottom of the prepared holes with enough extending above the surface to achieve the desired foundation height. Once set, the lengths of the tubular forms can be adjusted to the correct heights to assure a level foundation.
Set the forms in the prepared holes and rake excavated soil around them. Once the tubes have been properly leveled, tamp the soil firmly around the forms to hold them securely. After all pier forms are in place the heights can then be adjusted using a water or laser level to produce a level foundation.
Pouring the Concrete
Since concrete pier foundation construction is not nearly as labor intensive as slab foundations, the concrete can be mixed on site rather than ordering it from a ready-mix concrete company. A plastic or metal pail facilitates pouring the prepared concrete into the tubular forms. The concrete can be worked with a stick or rod to eliminate any entrained air pockets. The final step is the installation of a leveled J-bolt in the center of each pier for use as foundation attachments points. Once the concrete has set, foundation construction can then proceed.
Reference:
- Schmidt, Phillip. The Complete Guide to Contemporary Sheds. Minneapolis: Creative Publishing, 2008. Print.
Larry Darter - Larry Darter is a freelance writer and published author with three books to his credit. He is a graduate of the Univ. of Central ...
