Please see the full article: 2021 Basement Waterproofing Costs | Average Cost To Seal Walls (homeguide.com)

$3 – $9 Per Square Foot
roughly $1,920 – $6,320 on average.

Waterproofing a 1,000 sqft. basement costs $4,118 on average, or about $3 to $9 per square foot, which includes sealing interior and exterior walls. Minor repairs and crack filling cost $1,500, while complete drainage improvements range from $2,000 to $6,000. Some waterproofing contractors charge on a per-project basis, or per linear foot. Get free estimates from basement waterproofing companies near you.