Waterproofing Contractors Insurance Requirements in Washington

Waterproofing defects are almost always discovered long after the work is completed — a failed membrane may not allow water intrusion until seasonal water table changes or heavy rain expose the defect months or years later. Without completed operations coverage, the contractor's GL policy would not respond to a claim filed after the project is finished. This is the single most important coverage to verify for waterproofing contractors.

A manufacturer's warranty covers material defects and is typically backed by the waterproofing product manufacturer for 5–20 years. Insurance covers installation errors, workmanship defects, and resulting property damage. Both are needed because a warranty will not cover water damage caused by improper application of a perfectly good product, and insurance will not cover material failure of a properly installed but defective product.

Yes, particularly for contractors using solvent-based coatings, chemical injection systems, or hot-applied membranes. These products generate fumes that can cause health complaints in occupied buildings and may contaminate soil or groundwater if improperly handled. Standard GL policies exclude pollution claims, so separate pollution liability of at least $500K is recommended for any chemical-intensive waterproofing work.

Parking deck waterproofing failures can cause water damage to occupied spaces below the deck, creating extensive property damage and tenant displacement claims. Require $2M/$4M GL with completed operations extending at least 10 years. Obtain both manufacturer's material warranty and contractor's workmanship warranty. Implement a regular inspection program to catch membrane deterioration before it allows water infiltration.

Licensing requirements for waterproofing contractors vary by municipality in Washington. Check with your local licensing board and always request proof of current licensure on the COI.

In Washington, you as the property manager could be held liable for injuries or damages caused by an uninsured waterproofing contractors on your property. Washington courts have consistently ruled that property owners have a duty to verify contractor insurance before allowing work to begin.