National Home Inspector Exam (NHIE) Site, Grounds, and Exterior Summary

Rain and snowmelt should run away from the house. Under common model codes, the ground next to the foundation typically falls at least 6 inches within the first 10 feet (about a 5% slope). This keeps water from soaking the soil against the foundation, which can cause wet basements, crawlspace moisture, and soil pressure on the walls.

Wrong choices

• Sloped away from the house, falling only about 1 inch within the first 10 feet: About 1 inch over 10 feet is too flat. Water can still sit near the foundation.
• Perfectly level for the first 10 feet: Level ground lets rainwater pond against the foundation instead of running off.
• Sloped toward the house so water reaches the footing drains: Footing drains are a backup. Sending surface water toward the house leads to wet basements and foundation damage.

"Negative grade" (also called reverse grade) means the ground slopes toward the house. Water then runs to the foundation instead of away from it. Inspectors report it because it is a common cause of wet basements and crawlspaces.

Wrong choices

• Ground that is lower than the street: A lot can sit below the street and still slope away from the house. Negative grade is about the direction of slope next to the house.
• Soil that is below the frost line: The frost line is the depth soil freezes in winter. It has nothing to do with the slope of the yard.
• Bare soil with no grass or plants: Bare soil may erode, but negative grade describes slope, not ground cover.

Wood that stays damp rots and attracts termites. Under common model codes, wood siding and wall framing on the outside of a house typically need at least 6 inches of clearance above the soil, unless the wood is pressure-treated or naturally decay-resistant. Soil or mulch piled up against siding is a common finding.

Wrong choices

• 2 inches: About 2 inches is the clearance commonly allowed above hard surfaces like a concrete patio slab, not above soil.
• 1 inch: One inch is far too close. Splashing rain and soil moisture will keep the wood wet.
• 24 inches: This is more than the typical requirement. It is not the common model code value.

A roof collects a large amount of water in a storm. Downspouts should end at splash blocks, extensions, or a working underground drain that carries the water away from the house. Downspouts that dump at the foundation are a common, easy-to-fix defect.

Wrong choices

• Directly at the base of the foundation wall: Dumping roof water right at the foundation is a leading cause of wet basements and foundation problems.
• Into a basement window well: This fills the window well with water, which can leak through the window into the basement.
• Into the crawlspace through a foundation vent: This puts water exactly where it causes rot, mold, and settlement.

The ledger is the board that connects a deck to the house. Ledger failure is a leading cause of deck collapse. Nails can pull out under load, so ledgers are typically attached with lag screws, through-bolts, or listed structural screws. A nails-only ledger should be reported as a safety defect.

Wrong choices

• A ledger fastened with lag screws in a staggered pattern: Properly sized lag screws in a staggered pattern are a common accepted method.
• A ledger fastened with through-bolts and washers: Through-bolts with washers are one of the strongest accepted methods.
• A ledger fastened with structural screws listed for ledger use: Screws listed and installed for ledger use are an accepted method.

Under common model codes (IRC), a guard is typically required where a deck, porch, or other open side of a walking surface is more than 30 inches above the floor or grade below (measured within 36 inches horizontally of the edge). Missing guards are a serious fall hazard.

Wrong choices

• 36 inches: 36 inches is the typical minimum guard height, not the height that triggers a guard.
• 12 inches: This is lower than the common trigger height for a guard.
• 48 inches: Waiting until 48 inches would leave many dangerous drops unprotected.

For one- and two-family homes, the IRC typically requires guards to be at least 36 inches high, measured from the deck surface. Guards that are too low or loose should be reported as a safety concern.

Wrong choices

• 30 inches: 30 inches is the drop height that typically triggers the need for a guard, not the guard height.
• 42 inches: 42 inches is common for commercial buildings, not the typical residential minimum.
• 24 inches: This is too low to keep an adult from falling over.

Guards protect small children as well as adults. Under common model codes, the spaces between balusters (and other openings) typically must not let a 4-inch sphere pass through. That is about the size of a young child's head.

Wrong choices

• 6 inches: A 6-inch gap is wide enough for a small child's head or body to slip through.
• 9 inches: This is far too wide to protect children.
• 12 inches: This would allow a child to fall through easily.

Some water always gets past siding. Head flashing above a window or door catches that water and sends it back outside, over the top of the trim. Missing or reverse-lapped flashing can lead to rot in the wall framing around the window.

Wrong choices

• To act as decorative trim over the window: Flashing may be hidden or plain. Its job is water control, not looks.
• To insulate the window opening: Flashing is thin metal or membrane. It does not insulate.
• To hold the window in the frame: Windows are held by fasteners or nailing fins, not by head flashing.

Water that collects between a deck ledger and the house can rot both the ledger and the house rim joist. Over time the fasteners lose their grip and the deck can pull away. Flashing over the ledger sheds water out and away from this joint.

Wrong choices

• To help support the ends of the deck joists: Joist hangers and the ledger fasteners carry the load. Flashing carries no load.
• To electrically bond the deck to the house: Flashing is for water control, not electrical bonding.
• To keep the deck surface level: Flashing does not level the deck.