Foundation Issues - Question about Elevation Survey
Our house was built in 1988. We've seen some symptoms (doors that won't close, cracked door frame, minor cracks in ceiling, and now in the last month, a diagonal crack about 8" long, 1/16" wide along another wall). We recieved an estimate from a foundation company to put in 12 piers along the blue points of the elevation survey. I feel like the work is legit but would like to get a better understanding of how much difference is enough to warrant the repair. We have two points that are an inch or more below the base line of the house. I know next to nothing about this type of thing. Thoughts?