Site and Foundation Evaluation Flashcards

Under the IRC, what minimum fall should lot grading provide away from a foundation within the first 10 feet?

Answer: 6 inches

IRC R401.3 requires grade to fall at least 6 inches within the first 10 feet from the foundation.

Impervious surfaces such as driveways and patios within 10 feet of a building should slope away at a minimum of what percentage?

Answer: 2%

IRC R401.3 requires impervious surfaces within 10 feet of the foundation to slope at least 2% away.

An inspector sees a stair-step crack running diagonally through the mortar joints of a concrete block foundation wall. What is the most likely cause?

Answer: Differential settlement

Stair-step cracks along mortar joints usually mean one part of the foundation has settled more than another.

A long horizontal crack near mid-height of a block basement wall, with the wall bowing inward, most likely indicates what?

Answer: Lateral soil or hydrostatic pressure

Horizontal cracking with inward bowing is a classic sign of outside soil or water pressure pushing on the wall.

What is the most likely cause of a white, powdery deposit on the interior face of a poured concrete basement wall?

Answer: Efflorescence from moisture migration

Efflorescence forms when water carries soluble salts through masonry or concrete and leaves them behind as it evaporates.

Which soil type is most prone to significant swelling and shrinking with changes in moisture content?

Answer: Expansive clay

Expansive clays absorb water and swell, then shrink as they dry, which can heave or crack foundations.

Downspouts that discharge right at the base of a foundation wall most commonly cause what?

Answer: Saturated soil and basement or crawlspace water intrusion

Concentrated roof runoff at the foundation soaks the soil next to it and often leads to leaks and hydrostatic pressure.