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Quick, low-risk steps

  1. Stay out of water near electricity and call 811 before any digging.
  2. Record where water enters, when it happens, and whether plumbing is involved.
  3. Ask each bidder to state the proposed water source and evidence for exterior work.
  4. Compare drainage, discharge, demolition, restoration, and warranty in each quote.
  5. Check gutters and visible grading from safe areas before committing to excavation.

What Exterior Waterproofing Involves

Exterior waterproofing starts with excavation to expose the foundation wall. Workers dig a trench around the perimeter, often down to the footing. The depth and width depend on the foundation and access. This is heavy equipment work that disturbs landscaping, walkways, and decks.

Once the wall is exposed, it is cleaned and inspected. Cracks are repaired, and a waterproof coating or membrane is applied. A drainage board or dimple mat may be added to protect the coating and guide water downward. A new or replacement footing drain (French drain) is installed at the base, covered with gravel, and connected to a sump pump or daylight drain.

  • Excavation depth typically reaches the footing, but exact depth varies.
  • Waterproof coatings can be liquid-applied or sheet membranes.
  • Drainage boards protect the waterproofing and reduce hydrostatic pressure.
  • Footing drains must slope to a discharge point or sump pit.
  • Backfill material should be clean gravel to promote drainage.

Drainage and Discharge

The footing drain collects water from the soil and directs it away. It must lead to a sump pump, storm sewer, or daylight outlet. The discharge point should be far enough from the house to prevent water from returning. Local codes may dictate where water can be released.

A sump pump may be needed if gravity drainage isn’t possible. The pump moves water from a pit to the outside. A backup pump or battery is wise in case of power failure. The discharge pipe must be protected from freezing and clogging.

  • Discharge must be directed away from the foundation.
  • Check local rules about connecting to storm sewers.
  • A sump pump requires a dedicated electrical circuit.
  • Backup pumps can be battery-powered or water-powered.
  • Ensure the discharge line is clear and sloped properly.

Restoration and Site Work

After the waterproofing and drainage are installed, the trench is backfilled. The top layer may be soil for planting or hardscape. Landscaping, patios, and walkways disturbed by excavation will need repair or replacement. This can be a significant part of the project cost.

Restoration should be detailed in the contract. Ask who is responsible for replacing plants, sod, concrete, or asphalt. Some contractors include basic restoration; others leave it to the homeowner. Get a clear scope of work before signing.

  • Backfill should be compacted in layers to prevent settling.
  • Topsoil and seed or sod may be needed for lawn areas.
  • Concrete and asphalt replacement requires separate trades.
  • Fences, decks, and utilities may need temporary removal.
  • Confirm restoration details in writing.

Comparing Quotes and Making Decisions

Exterior waterproofing is a major investment. Get at least three detailed quotes. Each should explain the water source, the proposed solution, and the scope of work. Beware of bids that are vague or lack a drainage plan.

Ask about warranties for materials and workmanship. Understand what is covered and for how long. Check that the contractor is licensed and insured. A permit may be required; the contractor should handle this. Professional review of your specific situation is essential before proceeding.

  • Quotes should itemize excavation, waterproofing, drainage, and restoration.
  • Ask for proof of insurance and licensing.
  • Warranties vary; read the fine print.
  • A permit may be needed for drainage connections.
  • Consult a structural engineer if foundation damage is suspected.

Take this with you

Evidence and scope checklist

  • Proposed water source and evidence
  • Linear feet of excavation and depth
  • Type of waterproofing membrane or coating
  • Drainage board or protection board details
  • Footing drain material and slope
  • Discharge method and location
  • Sump pump and backup system specs
  • Backfill material and compaction
  • Restoration scope: landscaping, concrete, decks
  • Permit and inspection requirements
  • Warranty terms and duration
Open the interactive private worksheet →

Common questions

What homeowners ask next

Is exterior waterproofing better than interior?

It depends on the water source and foundation condition. Exterior work stops water before it reaches the wall but is more disruptive. Interior systems manage water that has already entered. A professional assessment can help decide.

Do I need a permit for exterior waterproofing?

Permit requirements vary by municipality. Work involving drainage connections or structural changes often needs a permit. Your contractor should know local rules and handle the process.

How long does exterior waterproofing last?

Longevity depends on materials, installation quality, and soil conditions. Warranties may range from 10 years to lifetime, but read the terms carefully. Proper maintenance of gutters and grading also affects durability.

Evidence

Sources used for this guide

Research checked July 31, 2026

Optional next step

Need an on-site professional?

Use the guide and worksheet first so you can describe the situation and compare the full scope. A referral is optional; you can also contact a licensed local provider directly.

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