Grading & Drainage Inspection: How to Document Water Management Issues

Every experienced home inspector knows this: grading and drainage issues show up on more inspections than almost any other deficiency. Negative grading, clogged gutters, missing downspout extensions, standing water near foundations — these aren't exotic findings. They're the bread and butter of exterior inspections. And they cause more long-term damage to homes than most of the dramatic stuff buyers worry about.

The challenge for inspectors isn't spotting grading and drainage problems. Most of us can identify negative slope by eye within seconds of walking a property. The challenge is documenting them thoroughly enough to hold up — whether the client is negotiating repairs, filing an insurance claim, or making decisions about a purchase. Vague language like "grading appears to slope toward the foundation" doesn't cut it. Measurements, photos, and specific descriptions do.

This guide covers the technical standards for proper grading and drainage, the common defects you'll find in the field, and practical documentation techniques that turn your observations into clear, defensible report content.

Why Grading and Drainage Matter

Water is the number one enemy of residential structures. Not fire, not wind, not termites. Water. And the first line of defense against water intrusion isn't the foundation waterproofing or the sump pump — it's the grading and surface drainage that keep water away from the foundation in the first place.

When grading fails, the consequences cascade:

• Foundation moisture — Water saturates the soil against the foundation, creating hydrostatic pressure
• Basement and crawl space flooding — Water finds the path of least resistance — usually through foundation cracks or cold joints
• Foundation movement — Saturated expansive soils push against foundation walls; dry cycles cause settlement
• Mold and moisture damage — Persistent moisture in basements, crawl spaces, and lower-level walls feeds mold growth
• Structural deterioration — Prolonged moisture exposure degrades foundation materials, sill plates, and framing

For related foundation concerns, see our foundation inspection guide. For basement-specific documentation, check our basement inspection guide.

The Grading Standard: 6 Inches in 10 Feet

The benchmark is simple: the grade should fall a minimum of 6 inches within the first 10 feet from the foundation wall. After that initial 10-foot zone, the grade should continue to slope away from the structure toward its natural drainage path.

How to Measure in the Field

You don't need surveying equipment. A few basic tools get the job done:

Method 1: 10-Foot Straightedge and Level

1. Place a 10-foot straightedge (a 2x4 works fine) against the foundation wall, one end touching the wall at grade level
2. Level the board horizontally using a spirit level
3. Measure the gap between the far end of the board and the ground
4. That measurement should be at least 6 inches (grade slopes down)
5. If the measurement is less than 6 inches, or the ground is higher than the board, you have a deficiency

Method 2: String Line and Tape Measure

1. Attach a string at the base of the foundation wall at ground level
2. Run the string out 10 feet, keeping it level (use a line level)
3. Measure the vertical distance from the string to the ground at the 10-foot mark
4. Same standard: 6 inches minimum

Method 3: Laser Level

1. Set a laser level at foundation base height
2. Walk 10 feet out and measure from the laser line to grade
3. Quick, accurate, and works well on large properties

When 6/10 Isn't Achievable

Some properties can't achieve the 6-inches-in-10-feet standard due to:

• Adjacent property lines — The neighbor's lot prevents regrading
• Walkways and driveways — Hardscape next to the foundation
• Mature landscaping — Retaining walls, gardens, or trees that can't be relocated
• Lot grading constraints — Flat lots or lots that naturally drain toward the structure

In these cases, document the constraint, note the actual slope measurement, and recommend alternative drainage solutions: swales, French drains, or regrading where feasible. The standard still applies — the question is how to achieve it given the site's limitations.

Common Grading and Drainage Defects

Negative Grading

The most common finding. The grade slopes toward the foundation instead of away from it. Causes include:

• Soil settlement — Backfill around new construction settles over time, creating reverse slope
• Landscaping additions — Mulch beds, flower gardens, and raised planters built up against the foundation
• Root systems — Tree and shrub roots redirect soil and change grade patterns
• Erosion — Water runoff carves channels that redirect flow toward the structure

How to document: Measure and photograph. "Negative grading observed along the east foundation wall. Grade slopes approximately 3 inches toward the foundation over a 10-foot run. Recommend regrading to achieve minimum 6-inch fall per 10 feet away from the foundation."

Mulch and Soil Against Siding

A universal finding. Homeowners and landscapers pile mulch or soil against the house until it covers the foundation and contacts the siding material.

• Clearance requirement: Minimum 6 inches between grade/mulch and siding material
• Wood siding: Must be 6-8 inches above grade to prevent moisture wicking and insect access
• Stucco/EIFS: Must maintain weep screed visibility above grade

How to document: Photograph the contact point with a tape measure showing the clearance (or lack thereof). "Mulch/soil in contact with siding material along the north and east elevations. No visible clearance between grade and siding. Recommend maintaining minimum 6-inch clearance to prevent moisture damage and pest entry."

Downspout Discharge Issues

Gutters collect roof water. Downspouts deliver it to grade level. But where that water goes after it leaves the downspout determines whether it's a solution or a problem.

Common defects:

• No extensions — Downspout terminates at foundation wall, depositing all roof water directly at the base
• Short extensions — Extensions that only move water 2-3 feet from the foundation
• Extensions discharging onto negative grade — Water moves away from the foundation initially, then flows back
• Disconnected downspouts — Gutter-to-downspout connections failed, water sheets down the wall
• Buried discharge lines clogged — Underground extensions that are blocked with debris

The standard: Downspout extensions should discharge water at least 6 feet from the foundation, onto positive grade that continues to direct water away.

How to document: Photograph each downspout termination point. Measure extension length. Note the grade direction at the discharge point. "Downspout at northwest corner discharges directly at the foundation wall — no extension present. Recommend adding extension to discharge water minimum 6 feet from foundation onto positive grade."

Swale Deficiencies

Swales are shallow, graded channels designed to redirect surface water away from structures. They're common between adjacent homes, along property boundaries, and at the base of slopes.

Common problems:

• Filled or graded over — Homeowners or landscapers fill swales with soil, mulch, or plantings
• Insufficient depth or slope — Swale doesn't move water effectively
• Blocked by obstructions — Fences, sheds, or plantings block the swale's drainage path
• Erosion — High-flow events erode the swale channel

How to document: Photograph the swale path and any obstructions. Note its location relative to the homes it serves. "Drainage swale between subject property and north adjacent property appears to be partially filled/obstructed. Original grading intent to direct water toward [street/easement/etc.] may be compromised. Recommend evaluation by a drainage professional and restoration as needed."

Window Well Issues

Basement window wells collect water if they're not properly drained.

What to check:

• Window well drains — Should have a gravel base and ideally a drain pipe connected to the perimeter drain system
• Well depth — Deep enough that grade doesn't direct water over the well rim
• Covers — Transparent covers prevent debris and water accumulation while allowing light and egress
• Grading around wells — Grade should slope away from the window well perimeter

How to document: Photograph each window well showing the condition, depth, drain presence, and surrounding grade. "Window well at southeast basement window contains standing water approximately 4 inches deep. No visible drain. Well rim is at or below surrounding grade, allowing surface water to enter. Recommend installing window well drain, adding gravel base, and regrading surrounding area."

French Drains and Subsurface Drainage

French drains (perforated pipe in a gravel trench) collect subsurface water and redirect it away from the foundation. They're common solutions for persistent drainage problems.

What to check:

• Outlet condition — The drain must daylight (discharge to surface) somewhere downhill. Find and verify the outlet.
• Signs of clogging — Standing water above the French drain indicates it's not functioning
• Surface condition — The gravel trench should be visible and not buried under soil or compacted
• Discharge point — Water should discharge to a suitable location, not onto neighboring property or back toward the structure

Sump Pump Systems

When exterior grading can't fully manage water, sump pumps are the interior backup.

What to check:

• Pump operation — Pour water into the pit and verify the pump activates and removes water
• Float switch — Verify it moves freely and isn't stuck
• Check valve — Prevent backflow on the discharge line
• Discharge location — The discharge pipe should terminate at least 6 feet from the foundation onto positive grade
• Power source — Dedicated circuit, ideally with battery backup
• Pit condition — Clean, covered with a sealed or gasketed lid
• Alarm — High-water alarms are inexpensive and worth recommending

How to document: "Sump pump present in southeast corner of basement. Pump activated when tested with water. Discharge line terminates at foundation wall with no extension — recommend extending discharge minimum 6 feet from foundation. No battery backup observed — recommend adding battery backup for power outage protection."

Foundation Waterproofing Indicators

While you can't see below-grade waterproofing on an existing home, you can document indicators of its condition:

• Interior water stains — Horizontal staining on basement walls indicates water entry at a specific height
• Efflorescence — White mineral deposits on foundation walls show moisture migration through the concrete or masonry
• Spalling — Surface deterioration of concrete or masonry from freeze-thaw cycles on saturated walls
• Crack patterns — Horizontal cracks (hydrostatic pressure), vertical cracks (settlement), stair-step cracks in block (differential movement)
• Mold or musty odors — Persistent moisture creates conditions for mold growth. See our mold inspection guide for documentation specifics.
• Sealant and patch repairs — Previous attempts to address water intrusion from the inside

Documentation Best Practices

Photography

Good grading and drainage documentation relies on clear, contextual photos:

1. Wide establishing shot — Show the full side of the house and overall grade direction
2. Mid-range context — Show the specific problem area in relation to the foundation
3. Close-up detail — Show the measurement, the standing water, the soil contact, the crack
4. Include a reference — A tape measure, a level, or a ruler in the frame provides scale and proves measurement
5. Capture drainage paths — Photograph where water goes — from the roof to the gutter to the downspout to the grade and beyond

Measurement Documentation

• Always include numbers — "Approximately 3 inches of negative grade" is far more useful than "the ground slopes the wrong way"
• Reference the standard — "Grade slopes approximately 2 inches toward the foundation over a 10-foot run. The IRC minimum standard is 6 inches of fall away from the foundation over 10 feet."
• Note multiple measurement points — Grade varies around the perimeter. Document each elevation separately.

Report Language

Write your findings so that a homeowner, a real estate agent, a contractor, and an attorney can all understand what you observed and why it matters.

Weak: "Grading issues noted around the house."

Strong: "Negative grading observed along the east and south foundation walls. At the southeast corner, grade slopes approximately 4 inches toward the foundation over a 10-foot measurement. The IRC requires a minimum of 6 inches of fall away from the foundation within 10 feet. This condition directs surface water toward the foundation and increases the risk of moisture intrusion at the basement level. Recommend regrading these areas to achieve positive drainage away from the foundation."

Seasonal Considerations

Grading and drainage conditions change with seasons:

• Spring inspection — Best time to see drainage issues. Snow melt and spring rains reveal problem areas that are dry in summer.
• Summer inspection — Dry conditions may hide drainage issues. Look for staining, erosion patterns, and vegetation indicators (lush growth near foundation = persistent moisture).
• Fall inspection — Leaf accumulation in gutters, window wells, and swales. Drainage paths may be blocked.
• Winter inspection — Snow cover hides grade conditions. Ice damming at foundation may indicate drainage problems. Document limitations.

Note seasonal limitations in your report: "Inspection conducted during dry conditions. Grading measurements reflect current grade but do not account for seasonal drainage performance. Recommend monitoring during heavy rain events."

When to Recommend Further Evaluation

Some drainage situations exceed the scope of a general home inspection:

Common Grading Fixes You'll Recommend

While you don't prescribe specific repairs, understanding common solutions helps you communicate effectively:

• Regrading — Adding soil to create positive slope. The most common and cost-effective fix for negative grading. Typical cost: $500-$2,500 depending on area.
• Downspout extensions — Adding splash blocks or underground piping to move water further from the foundation. Typical cost: $50-$300 per downspout.
• French drain installation — Perforated pipe in a gravel trench to intercept and redirect subsurface water. Typical cost: $1,000-$5,000 depending on length.
• Swale creation or restoration — Grading a shallow channel to redirect surface water. Typical cost: $500-$3,000.
• Sump pump installation or upgrade — Interior solution when exterior corrections aren't sufficient. Typical cost: $800-$2,500.
• Window well drains and covers — Prevent water accumulation in window wells. Typical cost: $100-$500 per well.

Tying It All Together

Grading and drainage isn't glamorous. It doesn't have the drama of a failed electrical panel or the visual impact of a sagging roof line. But water damage accounts for more insurance claims and more structural deterioration than almost any other single cause. Every time you document a grading deficiency thoroughly — with measurements, photos, and clear language — you're protecting your client from the kind of slow, expensive damage that ruins basements, foundations, and home values.

The best inspectors don't just note "grading issues observed." They measure slope. They photograph drainage paths. They trace water from the roof to the gutter to the downspout to the ground and beyond. They tell the story of where water goes on this property — and where it shouldn't.

For inspectors looking to capture grading observations efficiently in the field, ReportWalk lets you dictate findings by voice on your iPhone as you walk the exterior — measurements, locations, and recommendations captured in real-time without stopping to type. When you're documenting grading conditions on all four sides of a property, voice-first reporting keeps your eyes on the grade and your hands free to measure.

Our exterior inspection checklist covers the full scope of exterior documentation beyond grading, and our crawl space inspection guide addresses the interior consequences when exterior drainage fails.