How to Install Drainable House Wrap

Knowing how to install drainable house wrap properly is essential for protecting a home from moisture damage. Unlike traditional house wraps, drainable wraps have built-in channels that direct trapped water away from the structure. This design helps reduce the risk of mold, rot, and siding failure.

However, incorrect installation can cause problems. If the wrap is not applied correctly, water may get trapped behind the siding, leading to long-term damage. To avoid this, follow these best practices to ensure the wrap performs as intended.

Why Use Drainable House Wrap?

A drainable house wrap does more than just act as a weather-resistant barrier (WRB). It improves moisture control in two important ways:

• Faster Drainage – Built-in gaps allow water to drain quickly, preventing buildup behind siding.
• Better Breathability – These wraps let moisture vapor escape while blocking liquid water, keeping walls dry.

For homes in wet or humid climates, installing drainable house wrap is an excellent way to improve durability and prevent costly repairs.

Getting Started: Choosing the Right Wrap

Not all drainable house wraps offer the same benefits. Before starting your project, consider these factors:

• Drainage Efficiency – Look for wraps that have been tested for rapid water removal.
• Vapor Permeability – A good wrap allows walls to dry while still blocking bulk water.
• Material Compatibility – Make sure the wrap works with wood, fiber cement, masonry, or stucco.

Once you have the right product, it’s time to begin installation.

Step 1: Prepare the Surface

Before installing, make sure the wall sheathing (OSB, plywood, or rigid foam) is:

• Clean – Remove any dirt or debris.
• Dry – Avoid trapping moisture behind the wrap.
• Smooth – Eliminate sharp objects that could tear the wrap.

If you’re using foam sheathing, check that the house wrap allows enough airflow for the walls to dry properly.

Step 2: Start at the Bottom and Work Up

For the best results, always install the wrap from the bottom up. This method ensures proper water drainage.

• Begin at the base of the wall, extending the wrap at least 6 inches below the sill plate.
• Roll out the wrap horizontally, keeping it tight and smooth to prevent wrinkles that could trap moisture.
• Make sure the drainage side faces outward—this allows water to escape instead of being trapped.

Step 3: Secure the Wrap with Proper Fasteners

The way you attach the wrap is just as important as how you place it.

• Use cap nails or cap staples – Regular staples can puncture and weaken the wrap.
• Space fasteners every 12–18 inches along the top and bottom edges for a secure hold.
• Avoid overdriving fasteners – Pressing them in too hard can crush the drainage channels, reducing effectiveness.

Step 4: Overlap Correctly for Proper Drainage

To ensure water flows outward, overlapping the wrap correctly is crucial:

• Horizontal seams: Overlap by at least 6 inches to create a shingle effect.
• Vertical seams: Overlap by at least 12 inches and stagger them to avoid creating a direct water path.
• Do not tape horizontal overlaps – This can block drainage channels and trap water behind the wrap.

Step 5: Flash Windows & Doors Properly

Windows and doors are common weak points for moisture penetration. To prevent leaks:

• Cut an “I” or “X” shape in the wrap over each window and door opening.
• Fold the flaps inward and secure them inside the rough opening.
• Apply flashing tape in this order: sill first, then sides, then top for a watertight seal.
• Install drip caps or head flashing above windows and doors for extra protection.
• Do not tape the bottom of window openings—this can trap water instead of letting it drain.

Step 6: Seal Penetrations & Joints

Any opening in the wrap—such as around vents, pipes, or electrical boxes—needs to be properly sealed:

• Use flashing tape to seal around penetrations.
• Ensure all vertical seams are sealed to prevent air leaks.
• Avoid gaps in sealing – Even small openings can allow moisture to get in.

Step 7: Integrate with the Cladding for Maximum Protection

For the best moisture control, install siding with a ventilated gap between it and the wrap:

• Leave at least a ½-inch air gap between the cladding and wrap to allow water to drain.
• Use a rainscreen system for materials like stucco or masonry, which tend to hold moisture.
• Never install house wrap flush against stucco or brick – trapped moisture can cause early failure.

Common Mistakes to Avoid

• Using regular staples – These can damage the wrap, reducing its drainage ability.
• Blocking drainage channels – Taping horizontal overlaps prevents water from flowing out.
• Skipping the drainage gap – Installing wrap directly against cladding can trap moisture.
• Flipping the wrap the wrong way – Always install with the textured side facing out for drainage.

Final Thoughts on How to Install Drainable House Wrap

A properly installed drainable house wrap can make a huge difference in a home’s long-term durability. By following these steps, builders and contractors can ensure:

• Better moisture protection
• Increased siding lifespan
• Reduced risk of mold, rot, and cladding failure

For contractors and wholesalers, choosing a high-performance drainable wrap is just as important as installing it correctly.

Looking for a High-Performance Drainable Wrap?

If you want a drainable wrap that exceeds industry standards, consider TamlynWrap® Drainable Wrap. It offers:

• 100X faster drainage than standard house wrapshttps://www.capitalforest.com/
• Superior vapor permeability for quick drying
• Durability and UV resistance for long-term protection

Learn more about TamlynWrap® Drainable Wrap and other moisture management solutions at Capital Forest Products!