Click Business Name for More Information. Welcome to Keystone Foundation Repair, Inc. For over 20 years, we have served residential and commercial customers throughout Maryland and Pennsylvania with high quality foundation repair. Call the leader in the Mid Atlantic region for dependable service in Harrisburg, York, Carlisle, Hagerstown, West Chester PA, Lancaster and other PA cities and Baltimore, Frederick and surrounding areas of MD. We offer professional foundation repair in Pennsylvania and Maryland to address a range of problems, including structural damage, sunken foundations, leaning chimneys and cracks on the interior walls or exterior masonry. We utilize the best equipment and proven techniques to design a solution that will protect the integrity of your home and prevent further damage.