A strong foundation is advised for any life endeavor, and steel buildings are no exception. In fact, in addition to providing strength and stability, the foundation also will also help to protect your metal building components from moisture and water damage.
While pouring a foundation can be a do-it-yourself (DIY) project, we recommend working with a licensed concrete subcontractor or an experienced building professional the first time to make sure you follow industry best-practices. Any errors in surveying, land preparation or curing of the poured slab can lead to undesirable and costly consequences down the road.
7 Steps For Preparing Your Steel Building Foundation
If you want to build a foundation that lasts, we recommend following the steps below.
Get a building permit. Failing to build a permitted building that complies with federal, state and local building codes is a huge mistake. Not only can it lead to citations and fines, you can be required to tear down or rip out all or portions of your building to accommodate inspectors and permit the building after the fact. This can be extremely expensive. Also, failure to legally permit a building on your property can affect your ability to sell the property down the road since lenders can use that as grounds for refusing loans to prospective buyers.
The foundation permit is typically one of the first permits you'll pull and the first inspections you'll schedule. If you are new to the permitting process, schedule a meeting with your local building department official to ensure you go by the book from start to finish.
Site selection. Have you selected the best site on your property for your future metal building? It may be worth it to hire a professional to evaluate your property and help youselect the best location based on lot orientation, soil composition, water drainage and so on.
Site preparation. Once you've selected the best site location and have pulled the appropriate permits, it's time to prepare the ground for your foundation. The first step is to have surveyors visit the site and stake it accordingly. Depending on the type of soil on your property, you concrete subcontractor may recommend or even require that your soil be amended to accommodate site drainage and to provide adequate stability for your foundation. Soft soil or soil that does not drain properly can create issues later on.
Once the land has been surveyed, ground preparation will begin. This includes the removal of any trees, shrubs and large rocks. When the surface is clean, the ground will be leveled. While leveling work can be done by hand, we recommend having it leveled and graded by a professional, especially if your building is on the larger side. Most steel buildings require a deep base, between 2-inches and 3-inches deep. Larger or more complex steel buildings may require a more significant base. Do keep some of the excavated soil on site so it can be used later to level the ground and fill any remaining holes or depressions after foundation work is complete.
Decided on the type of foundation you will be laying. There are typically two types of foundations - ground mount or concrete slab. In most cases, we recommend using a poured concrete slab foundation for longevity's sake. However, homeowners who buildan additional metal garage, storage or workshop on their property may opt for a ground mount foundation for ease of installation. If you are going to use a concrete foundation, you, skip to Number 6.
Ground mount foundations.Even though you are bypassing the concrete slab, your building still needs to be anchored firmly to the ground. In most cases, this will require you to dig post holes that are at least 10-inches wide and 30-inches deep, every four to five feet along the perimeter, depending on your building plans. Deeper holes may be required in colder climates to accommodate the frost line. You will use a 2500 psi concrete mixture in the holes and this mixture should be allowed to cure for at least seven days before construction continues.
Concrete slab foundations. If you're using a concrete slab, your concrete mixture should meet a minimum 2500 psi requirement and should be used in conjunction with steel mesh reinforcement. The slab should be poured to the exact width of your building and 2-inches longer than the building's length. You will also include four perimeter footings that are 12-inches wide and 12-inches deep (deeper if you need to accommodate for the frost line). Sand, gravel and a vapor barrier will be used first, then the concrete will be poured.
Cure your slab correctly. Failure to adhere to proper curing instructions can cause your slab to lose 50% of its strength and cohesiveness over time. Optimal curing conditions are between 50° and 90° F.