There are several types of foundations used in residential construction but all have one important requirement, the foundation and connections to the walls and floors must be strong enough not only to support the weight of the house and its contents but to prevent the home from being blown away by high winds.
Common Foundation Types
The two most common types of foundations are monolithic slab-on-grade and stemwall foundations.
A slab on grade foundation is a single, continuous layer of concrete that sits directly on the ground. The concrete slab is the floor system. A slab-on-grade foundation should be reinforced with welded wire fabric and have longitudinal reinforcement in the footing or turndown.
Construction Techniques
There are many construction techniques for anchoring the exterior walls to the foundation.
For wood-framed construction, the bottom plate of the wall should be anchored into the slab with anchor bolts and washers.
The bottom plate should be securely connected to the wall studs above by using approved metal clips or straps.
For concrete masonry construction, vertical reinforcement in a continuously grouted cell should extend from the wall above and be embedded in the concrete footing below with a standard hook.
Stemwalls
A stemwall is a concrete block or brick wall used on top of the footer for off grade houses where the ground slopes from one side to the other.
Stemwalls can support both concrete slabs and wood-framed floors.
Stemwalls should have vertical reinforcement in a continuously grouted cell extending from the concrete masonry wall and embedded in the concrete footing with a standard hook.
The concrete footing should also have longitudinal reinforcement.
Anchorage for an exterior wall to a stemwall foundation is similar to anchoring to a slab-on-grade.
Metal connectors and anchor bolts must be used to securely connect the walls to the foundation and give your home the required resistance to the forces created by extreme winds.