What “structural” looks like from the basement
Foundation walls carry the house and hold back soil. A dry crack is not automatically harmless, and a wet crack does not automatically mean you only need a drain. From a dry, safe spot, look for bowing or lean, cracks that are wider at one end than the other, horizontal cracks, stair-step cracks in block, displaced masonry, sticking doors upstairs, or floors that slope. Photograph the whole wall and the crack, date the photos, and note when water shows up.
FEMA’s homeowner foundation check says cracks greater than ¼ inch can point to further foundation issues and should be monitored, and that horizontal cracks can signal stress on the foundation (FEMA — Inspect wall-to-foundation anchorage). That is a screening tip for when to get a professional look, not a DIY pass/fail ruler. Do not excavate beside the wall, drill into it, or strip finishes yourself to “investigate” a wall that may be structural.
When waterproofing should lead
Once structural concerns are ruled out or repaired, a waterproofing contractor should explain the water path—not assume every wet spot needs the same fix. The Building America Solution Center lists three common approaches for stopping basement water: exterior wall waterproofing, exterior perimeter drainage, and interior drainage below the slab (Building America — Basement / Foundation). Ask which of those the proposal is actually doing: blocking entry, collecting water after it enters, or improving drainage around the foundation.
Also rule out indoor sources such as plumbing leaks or equipment condensate before you buy an exterior dig. Our guides on interior drainage versus exterior waterproofing and what to document when water appears in a basement help you compare scopes. Seasonal timing matters too—see why a basement can leak only during snowmelt if the pattern is meltwater, not every rain.
Get a written engineering read before you buy a “system”
Ask the engineer for a written assessment that names the wall, what was visible, likely cause, limits of the inspection, urgency, and next steps—monitoring, further investigation, or a repair design. Prefer language you can hand to competing contractors. Ask whether any proposed waterproofing, excavation or sump work affects the structural plan, and who approves changes if concealed conditions differ.
Before insulating or finishing the basement, Building America guidance says to evaluate structural integrity and moisture first—standing water and moisture sources should be corrected before other work proceeds (Building America — Pre-retrofit assessment of crawlspaces and basements; air-sealed, insulated basements). A water-collection system, coating or leak warranty is not the same thing as a written finding that the wall is structurally adequate.
Philadelphia permits if the fix digs or alters structure
In Philadelphia, ask Licenses & Inspections which permits apply before you authorize work. An Excavation Site Permit is required for a cut, trench or depression more than five feet below an adjacent grade, and a Philadelphia-licensed excavation contractor must do that work (City of Philadelphia — Excavation Site Permit). A Building Permit is required before projects that change the structure, and L&I’s building-permit page says excavation more than five feet below adjacent grade must be included on the building permit or covered by a separate Excavation Site Permit first (City of Philadelphia — Building Permit). For waterproofing and sump scopes specifically, see whether Philadelphia requires a permit for basement waterproofing or a sump pump. Ask what must stay open for inspection before any new wall covering goes up.