Clay soil, slab foundations and what they mean for you

The Texas Section of the American Society of Civil Engineers lists indicators such as cracking of drywall walls and ceilings, walls separating from ceilings or floors, racking of door and window frames, and cracking or buckling of floor coverings. Doors that bind or will not latch are among the most common.

Look for cracks in brick veneer, brick that rotates or bulges, separation at window frames and trim, and cracks in the exposed concrete of the slab edge. Brick coursing that is not level can also point to movement.

The same ASCE Texas guidelines caution that observing some of these conditions does not necessarily mean the structure is performing inadequately, and that the age of the home and any previous repairs matter. Context is everything.

The guidelines note that a floor slope greater than 1 percent is usually noticeable, and that the Americans with Disabilities Act considers a 2 percent slope too large. Rolling a marble is not a measurement; an engineer's elevation survey is.

Under TREC's standards of practice (22 TAC 535.228), a Texas home inspector must give a written opinion on the performance of the foundation and report visible indications of adverse performance, such as binding or out-of-square doors and sloping floors. An inspector is not required to provide an exhaustive list of indicators.

When the inspector flags movement, the usual next step is a licensed professional engineer. The ASCE Texas guidelines say an engineer may use a floor elevation survey but that it should not be the only basis for evaluating deflection and tilt, because the original slab shape is unknown without an as-built survey. A good report states its data, assumptions, conclusions and recommendations.

A repair contractor installs the fix, often to a plan. Frisco requires a permit for foundation repair with a stamped engineer letter and stamped pier drawings, and the engineer must provide an inspection report at completion. That makes the engineer's role part of the city's process, not just a nice extra.

Getting an independent engineer's evaluation before a repair bid separates the diagnosis from the sale. It also gives buyers, sellers and appraisers a document they can rely on.

The ASCE Texas guidelines describe non-structural measures that may improve performance and reduce future movement: keeping soil moisture near uniform on all sides of the foundation (while avoiding overwatering), managing trees and large shrubs near the slab, root barriers, gutters with downspouts that discharge well past the foundation and planting beds, and grading that slopes away from the house at about 5 percent (6 inches in 10 feet) for the first 5 feet where practicable.

For slab foundations, the guidelines list repair methods including underpinning (piers), grouting, mudjacking, crack injecting, tendon stressing and partial demolition and reconstruction. The engineer of record should specify locations, sizes and depths and require a floor elevation survey after the work.

The guidelines are candid that perfection is not attainable by remedial measures and that every approach carries some risk of continued movement. They also note some owners reasonably choose periodic cosmetic repairs and door adjustments over full underpinning.

Frisco's Water Management Plan limits sprinkler watering by season: one day a week in spring and fall, two days a week in summer, and no rotor or spray watering of turf from November 1 to March 31. The city lists hand-held hoses, soaker hoses and drip irrigation as options, and drip-irrigated landscape areas may water any day when needed. If foundation watering is part of your plan, confirm the current rules with Frisco Water Resources at 972-292-5800.

The TREC Seller's Disclosure Notice asks about known defects in the foundation or slab, settling or soil movement, improper drainage, and previous structural or roof repair. If you had work done, attach the engineer's report, the repair invoice, the city permit and any warranty.

If you suspect movement, an engineer's report before listing lets you decide whether to repair or price it in, instead of reacting to a buyer's inspection during the option period.

Under the TREC resale contract, the option period lets you terminate for any reason. If the inspector flags movement, schedule an engineer inside that window, not after.

Many repair companies offer warranties, and terms vary, including whether they transfer to a new owner and what it costs. Ask for the warranty document itself and read the transfer terms.

Since Frisco requires a permit for foundation repair, a past repair should show up in the city's eTRAKiT permit search. A repair with an engineer's completion report and a closed permit is far easier to explain to a buyer and an appraiser.