When you have an addition put on your home, you need to add a foundation even if the addition is going to be small. The foundation not only keeps the addition stable, but it also keeps it meeting local code and prevents some really unnecessary damage. It may be tempting to skip the foundation or put a very cheap, fast one in, but don't skimp on the foundation at all.
Frost Heave and Unstable Soil Can Wreak Havoc Without a Foundation
You may think setting a small home addition on the surface soil without a foundation is going to be okay; after all, it's just a small percentage of the home's total square footage. But the point of a foundation is to ensure the structure on top of the foundation stays in good shape, stays level, and stays attached to the main house. Without that foundation, frost heave in the soil, or soil erosion due to rain, your home addition can be unlivable. Frost heave is when the soil heaves up after the moisture in the soil has turned to ice. The ice expands, pushing the soil on top up and out. Erosion due to rain can quickly make things worse, too, by washing away soil that's under the edges of the addition.
Whichever You Choose, It Has to Go Below the Frost Line
No matter what type of foundation you choose, though, it (or its supports and posts) have to sit below the frost line. They have to rest on soil that is not in danger of freezing. When the foundation rests on soil that is not going to freeze, then the foundation will not rise or fall. You won't have to deal with cracks between the addition and the home. Each type of foundation has to sit at a certain depth, and if you have home remodelers doing the work, you can rest assured the foundation will be installed correctly.
Soil Preparation Is Essential
All the digging below the frost line won't do any good if the soil that will be under the foundation isn't compacted properly. That too can cause a home addition's foundation to move as the soil settles, and as a result, the addition could actually start to break away from the rest of the house. The settling lets the foundation drop down, and the rest of the addition will go with it. All soil has to be compacted very well before the foundation is installed, no matter what style of foundation you plan to use.
Adding a home addition can be a fantastic step toward improving your home, but the foundation has to be built correctly. Whether you're going for a full basement or just a slab, you must ensure frost heave and soil problems aren't going to make the home addition separate into its own standalone structure. For more information on home additions, contact a company near you.