Yesterday just before 1 p.m. there came a light rapping at the front door. “Be still my beating heart,” I told myself. The inspector is here!
His name is Mike and he is a licensed structural engineer who’s website described him as just the kind person you want inspecting your slab foundation: unbiased, independent, yet with years of experience in the concrete foundation business. Somehow he seemed taller in person.
Mike came in with his inspector gadgets: a carpenter’s level, clipboard, Stanley Compulevel, a laser “tape” measure, and a solid state voice recorder that he would mutter into now and then as though he was doing an autopsy on my house.
He went through the house and made a sketch of the floor plan, checked the doors and noted the cosmetic damage like buckled sheetrock tape and cracks. The room where I write this has a good sized crack where two sheets of wallboard join up, or used to, and the wall I’m facing has a 1/4 inch separation from the ceiling joint.
Outside, Inspector Mike looked for cracks or separations in the brick veneer and made note of the drainage and landscaping including an oak tree that is 12 feet from a back corner of the foundation.
Coming back inside, he fired up his trusty Compulevel. He set the main unit in the hall and unreeled enough tubing from it to reach the other rooms in the house. The tubing is charged with a gas that enables the instrument to measure minute changes in atmospheric pressure and thus variances in the rise or fall of a foundation.
Mike marched through the house with the head end which displays the readings. He wrote down the readings on the corresponding floor plan map he had sketched earlier.
By taking readings in every room, along walls and towards the center of each room, he developed a map of where the foundation varied in elevation from the high point, which turned out to be the kitchen near the garage door.
Inspector Mike’s report which was emailed later that evening showed my foundation about 5 inches low in the back of the house and lesser degrees of low elevation around the front and sides. I’m gonna need underpinning, but Mike suggests we first call an arborist to cap any roots going under the foundation, install a root barrier, and wait a year so see if we get some lift from stopping the tree from taking moisture out from under the slab in the back. The goal is not to avoid piers, but to get a better degree of level overall in that back room nearest the tree. I’ll let you know how it goes.