Why drainage matters more than almost anything

A dry basement starts at the roof and ends ten feet from the foundation wall. The wettest basements we see are almost never the result of a cracked wall — they are the result of bad drainage: a downspout that terminates at the corner of the house, a patio sloped inward, a flower bed that dumps water against the siding, or soil that has settled over 20 years and now grades toward the foundation instead of away from it.

Fix the drainage first. In most cases that alone will dry the basement; waterproofing contractors love to sell $12,000 interior French-drain systems to homeowners who needed a $400 landscaping correction.

Grading — the 6-inch-in-10-feet rule

Code and best practice: the ground should slope away from the foundation at a minimum of 6 inches of fall over the first 10 feet (a 5% slope). We walk the perimeter and look for:

• Visible negative slope (water would flow toward the house)
• Settled grade at the foundation — a trench or low spot along the wall
• Mulch, soil, or deck slabs above the top of the foundation — conceals potential damage and traps water
• Patios and walks sloped toward the house (checked with a 4-foot level)
• Downspout splash zones and erosion patterns

Gutters and downspouts

• Gutter condition: rust, sagging, improper pitch, separation from the fascia, leaves and debris clogging. In Minnesota, clogged gutters in November become ice-dam factories in January.
• Downspouts: present at every corner, properly secured, discharging into an extension that moves water at least 4 feet from the house.
• Downspout extensions: rigid or flexible pipe. We strongly prefer rigid, 6 feet or longer, discharging onto a splash block or into an underground drain leader.
• Underground drain leaders: if present we trace the daylight end to confirm it is not buried, crushed, or pointed back toward the foundation.

Site-level drainage

• Swales: shallow graded channels that carry surface water around and away from the house. Common in Savage and Prior Lake newer subdivisions.
• Sump pump discharge: must daylight at least 5 feet from the foundation and not re-enter the drain-tile system. Common inspection finding: discharge hose dumping right back at the wall.
• Window wells: must have gravel base, proper drainage, and a cover in winter. Frozen-over wells trap snowmelt.
• Rain gardens and low-maintenance landscaping: great if properly designed and sloped away from the foundation.

Evidence of past water intrusion we flag

Even if the basement is dry today, past evidence warns of future problems. We document:

• Efflorescence on interior foundation walls — white chalky mineral deposits from past water
• Water staining on stored items in the basement
• Rust on the feet of the water heater, furnace, or HVAC
• Visible high-water marks on the foundation at grade level
• Mold or mildew on joists and rim joists (cross-referenced with interior inspection)