Expansion Joint

An expansion joint solves a different problem than a control joint. A control joint manages shrinkage cracking within one continuous wall or slab, while an expansion joint separates two different sections, like a patio meeting a house foundation, or a long brick wall butting against a rigid structure, that need to move independently. Without one, the two sections push against each other as they expand in heat and contract in cold, which can crack or spall the material right at the seam.

With the wide temperature swings the Blue Ridge foothills go through, summer heat to hard winter freezes, expansion joints matter more here than they would in a milder climate. They keep patios, walkways, and long masonry runs from buckling or cracking where they meet a fixed structure like a foundation or driveway, and a joint packed with debris or paved straight over defeats the whole purpose.