Services
Exterior Waterproofing
Exterior waterproofing is the process of stopping water from ever reaching your foundation — by sealing the outside of the wall and redirecting groundwater away from it.
Our system, WallShield™, is a 2-layer engineered membrane installed against the foundation wall, combined with footer-depth drainage. Done right, it's a lifetime solution.
Every WallShield™ includes
Parging Coat (all wall types)
Smooth surface prep for membrane adhesion
Layer 1 — Cementitious Waterproofing
Polymer-modified mortar, penetrates cracks
Layer 2 — Bitumen Sheet Membrane
Self-adhesive, 60-mil thick, peel-and-stick
Footer-Depth Drain Tile
Relieves hydrostatic pressure behind wall
Lifetime Written Warranty
Transferable to next owner
When Exterior Is the Right Answer
Sometimes Water Hits the Wall — and Only the Wall
Exterior waterproofing isn't a default for every leak. But in certain situations, the source of water is unmistakably outside, against a specific wall — and the only way to stop it permanently is to seal the wall from the outside and relieve the pressure behind it.
Water Hits One Wall Hard
Heavy seepage concentrated on one wall — usually the uphill side — points to direct exterior water pressure, not floor-level entry.
CMU or Brick Walls
Block and brick foundations leak through mortar joints across the wall. Interior systems only catch what reaches the floor — exterior stops it before it enters.
Finished Basement Below
If the finished space is on the wet wall, exterior work doesn't disturb the interior — no drywall demo, no flooring removal, no displacement.
Visible Exterior Cracks
Cracks visible from the outside, efflorescence on the exterior, or failed prior waterproofing — these are exterior problems that need exterior fixes.
Why WallShield™ Is a Lifetime Solution
You Don't Have to Beat the Water — You Just Have to End the Fight
"Once the wall is waterproofed and the water is redirected, you haven't won the war against water — you've ended it. Water doesn't attack what it can't reach."
A lot of homeowners assume interior drainage is the only lifetime solution. It's not. Exterior waterproofing — done correctly — is just as permanent, often more so.
Here's why WallShield™ works for life: the 2-layer membrane creates a 100% waterproof barrier sealed against the wall. Then the drain tile system at footer depth relieves the hydrostatic pressure behind that wall — so even if groundwater rises, it has nowhere to push. The combination of sealing + redirecting means water no longer attacks your foundation. It moves around it, downhill, away. And if it ever does come back, the force has already been broken.
That's the engineering principle: waterproof the wall, then redirect the water. Two systems working together. One won't fight without the other. Your foundation gets a permanent break from the war.
The WallShield™ System
Parging + Two Engineered Layers
Surface Preparation
Parging Coat
Before any waterproofing, the entire foundation wall is parged — regardless of substrate. Block, brick, stone, poured concrete: all get parged. This creates the smooth, continuous surface the sheet membrane needs to fully adhere.
Required for all wall types. Part of the dual system, not optional.
Layer 1 — Cementitious
Polymer-Modified Waterproofing Mortar
A cement-based waterproofing slurry that bonds chemically with the wall and penetrates into hairline cracks. This is the first defense line — it locks the wall surface itself.
Products: Xypex, Aquafin, RapidSet
Layer 2 — Sheet Membrane
Self-Adhesive Bitumen Membrane
A thick, rubberized bitumen sheet membrane applied directly over Layer 1. Self-adhesive, peel-and-stick — creates a continuous, seamless waterproof envelope. This is the primary moisture barrier.
Product: GCP Bituthene 3000 (self-adhesive)
Our Process
8 Steps. Done in 3–5 Days.
Free Inspection
Engineer-trained inspector confirms exterior is the right approach, plans the excavation.
Site Protection
Protect landscaping, hardscape, AC units. Mark utilities. Stage equipment access.
Excavation to Footer
Hand and mechanical excavation along the wall — down to the bottom of the footer.
Wall Cleaning + Parging
Wall cleaned, loose material removed, polymer-modified parging applied over the entire surface.
Layer 1 — Cementitious
Polymer-modified waterproofing mortar applied. Chemically bonds with parging, fills hairlines.
Layer 2 — Bitumen Sheet
Self-adhesive bitumen sheet membrane installed. Continuous waterproof barrier.
Drain Tile + Drainboard
Footer-depth perforated drain tile, geotextile, washed gravel, drainboard. If grading is short, GradingShield™ adds drainage 1 ft below grade.
Compacted Backfill
Backfilled in lifts with mechanical compactor. Final grading restored away from the foundation.
What's Included
Every System. Every Component.
No mid-job surprises. Every WallShield™ installation includes everything below — written into your estimate.
Hand + Machine Excavation
Full depth to bottom of footer
Wall Cleaning + Parging
Smooth surface prep for full membrane bond
Cementitious Waterproofing
Layer 1 — penetrates hairline cracks
Bitumen Sheet Membrane
Layer 2 — self-adhesive, 60-mil thick
Drainboard Membrane
Protective dimpled layer over membrane
Footer-Depth Drain Tile
4″ perforated, geotextile wrapped
Washed Gravel Envelope
Hydraulic capacity around drain tile
Mechanical Compacted Backfill
Compactor lifts — not loose backfill
Lifetime Written Warranty
Transferable to next owner
Pricing Transparency
Honest Price Ranges. Free Written Estimate.
Exterior waterproofing runs approximately 25% more than interior because of the excavation, materials, and site restoration involved. Final pricing depends on linear footage, depth, site access, and grading.
Partial Exterior
$10K–$22K
One wall · 20–50 linear feet · Good site access
- Full WallShield™ 2-layer system
- Footer-depth drain tile
- Mechanical compacted backfill
- Site restoration
- Lifetime warranty
Full Perimeter Exterior
$22K–$40K+
Full perimeter · 100+ linear feet · Complex access
- Full WallShield™ all walls
- Footer-depth drainage all sides
- GradingShield™ if grading short
- Hardscape/landscape restoration
- Lifetime warranty
Free written estimate · 0% APR financing available through Wisetack
FAQ
Common Questions About Exterior Waterproofing
How is exterior different from interior waterproofing?
Interior (FootingShield™) catches water after it enters and channels it to a sump pump. Exterior (WallShield™) stops water from entering at all by sealing the outside of the wall and redirecting groundwater with a drainage system at footer depth. Both are lifetime solutions when done right — they just solve the problem from different sides.
When do you recommend exterior over interior?
When the water source is clearly outside hitting a specific wall (and the water table isn't extremely high). Common cases: CMU or brick foundations leaking through mortar joints, finished basements you don't want to disturb, visible exterior cracks, or failed prior exterior systems. If hydrostatic pressure is system-wide and the slab is cracking too, interior is usually the better choice.
Why two layers — isn't one membrane enough?
Each layer does something the other can't. The cementitious layer chemically bonds with the wall and penetrates hairline cracks the membrane can't follow. The bitumen sheet membrane provides the continuous, flexible, sealed barrier — but it needs a smooth, sound substrate to adhere properly. One without the other is a half-system. We install both, every time.
What's the warranty on exterior waterproofing?
WallShield™ carries a lifetime written warranty. The warranty is transferable to the next homeowner at no charge. The only thing that disturbs an exterior membrane is third-party excavation (someone digging against the wall later) — and we'll repair any work damage from any actual system failure for the life of the home.
Will exterior work damage my landscaping or driveway?
We dig, we restore. Plantings within the work zone may need to be transplanted or replaced — we'll discuss this during the estimate. Driveways, patios, decks, AC condensers, and hardscape are protected and reinstalled. The site is graded properly when complete so water moves away from the foundation, not toward it.
What if my yard doesn't have enough slope?
If existing grading can't carry water away from the foundation, we add GradingShield™ — a drainboard and drain tile system installed 1 foot below grade, just past the WallShield. This way drainage works at two levels: at the footer depth, and again near the surface. Same engineering principle — seal it, then move it away.
How long does an exterior project take?
Most exterior projects are 3 to 5 days depending on linear footage, excavation depth, and site access. Day one is excavation, days two and three are wall prep + membrane installation, day four is drainage and backfill, day five is grading restoration.
Do you do exterior on brick or stone foundations?
Yes — wall type doesn't matter. Block, brick, stone, poured concrete: all get parged first, then the full 2-layer WallShield™ system. The parging step is what makes a continuous, smooth surface for the membrane to adhere to, regardless of substrate.
Free Inspection
Get an Engineer's Diagnosis
An engineer-trained inspector visits your home, confirms whether exterior is the right approach, and gives you an honest written estimate. Same-week availability across all four branches.
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Four Branches Across DMV
Rockville · Kensington · Ashburn · Manassas
Free Inspection
No obligation · Engineer on-site · Same-week availability