EXTERIOR WATERPROOFER

How to Apply Weatherwood Exterior Waterproofer

Step 4 of the Weatherwood Finishing System

Step 1 — Create the Patina (Reactive Stain)
Step 2 — Refine the Tone (Maintenance Oil)
Step 3 — Protect the Finish (Architectural Topcoat)
Step 4 — Exterior Protection (Exterior Waterproofer)

Exterior Waterproofer is the only Weatherwood product designed for outdoor use. It penetrates into the wood, encapsulates the fibers, and forms a water barrier that protects against cupping, splitting, and twisting. Two back-to-back applications protect wood for 5–7 years.

Without proper exterior protection, wood will absorb moisture, move, and degrade over time — even if it’s been stained. Exterior Waterproofer is what makes outdoor Weatherwood projects last.

If you still have product, color, species, or ordering questions after reading this page, visit our FAQ page.

Before You Start

Mix product well before use.
Apply when air temperature is above 40°F.
Do not apply in rain, before rain, or in direct sunlight during warm weather.
Apply to all wood surfaces, especially including end grain.
Exterior Waterproofer must soak into the wood. Do not apply over sealed or film-coated surfaces — the product will not penetrate and will not protect.
Do not apply over Weatherwood Maintenance Oils or traditional polymer stains. Exterior Waterproofer must penetrate raw or reactive-stained wood to work. If combining with Maintenance Oil, apply Waterproofer first.

Compatible Surfaces

Raw lumber
Reclaimed wood
Barnwood
Weatherwood reactive-stained wood

Do not apply over Maintenance Oils, traditional polymer stains, or any sealed/film-coated surface.

Choose Your Application Method

Choose the method that matches your project scale:

Brush — best for jobsite application, fences, decks, and smaller exterior projects
Flood / Submerge — best for production environments, assembly lines, and high-volume siding operations

Brush Application

This is the standard method for on-site exterior projects.

APPLY

Apply a generous coat of sealer using short strokes and light pressure. Do not drag the brush on the wood.
Once the wood is covered, use long even strokes to even out. Do not wipe it back off. Allow the wood to absorb the sealer fully.
Apply in sections on larger projects, keeping a wet edge as you work.
Do not apply with heavy pressure.

SECOND COAT

Apply an additional coat of Exterior Waterproofer. In approximately 60 minutes the first coat should be dry.
When dry, wood is ready for install.

Flood / Submerge Application

Use this method for production environments with assembly lines, flood systems, or vats.

APPLY

Submerge wood in the Exterior Waterproofer for 5–10 seconds. Apply to all surfaces, especially end grain.
Make sure no air bubbles on the wood’s surface prevent exposure to sealer. Use a wet brush to remove bubbles if needed.
Ensure all surfaces are fully wetted. The goal is complete saturation, not extended soak time.
Leaving wood in too long may result in water marks.
Do not wipe off. Pull out, handling wood by the edges, and allow to air dry in racks. Do not stack wet wood on itself.

SECOND COAT

Apply an additional coat following the same steps. When dry, wood is ready for install.

Reapplication & Important Notes

When to Reapply

Reapply every 5–7 years, or when water no longer beads on the surface and begins to absorb into the wood. That’s your signal that the barrier has worn through.

Important Notes

Do not apply over Weatherwood Maintenance Oils or traditional polymer stains. Exterior Waterproofer must penetrate raw or reactive-stained wood to protect it. If you are using Maintenance Oil on an exterior project, apply Exterior Waterproofer first, then apply Maintenance Oil after the Waterproofer has dried.
Exterior tabletops may require an additional hard shell exterior protection to guard against food stains. We do not currently offer an exterior hard shell product.
When first applied, the wood will look darker and wet. This is normal — the finish dries back to the original tone. (See before/after photos above.)

If you still have questions about compatibility, sequencing with other products, or project-specific application, visit our FAQ page.