Protecting Mass Timber

VaproShield's high drying capacity, breathable membranes offer builders a comprehensive mass timber moisture protection strategy. From walls to decks, columns, and beams, our durable membranes are uniquely designed to protect mass timber projects before, during, and after construction.

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SlopeShield Plus Self-Adhered is designed to protect mass timber floors and decks and remains permanently installed.

WallShield IT provides temporary protection of vulnerable mass timber structural elements such as columns and beams.

PanelShield SA guards walls from damaging moisture intrusion especially through rough openings.

Minimize Moisture, Minimize Risk, Maximize Drying

Mass timber absorbs and retains significantly more moisture than traditional wood building materials. When wet, mass timber requires an extremely long period to dry due to its mass density. This time period is much greater than it would be for single layer plywood or OSB. The damage to mass timber can result in mold, staining, surface cracking, and can compromise structural performance.
Builders can avoid this costly damage by using SlopeShield Plus SA—a fully self-adhered high drying capacity sheet membrane—to simultaneously protect and dry the mass timber structure.

Wet Mass Timber WebImage 01Outer portions of mass timber layers may dry disproportionally faster compared to the inner layers, causing checking, staining, dimensional changes, and compromising structural values.

Mass Timber Moisture Protection Strategies

SlopeShield Plus SA

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SlopeShield Plus SA protects mass timber from bulk water intrusion and concurrently dries mass timber through moisture vapor diffusion.

Taped Splines

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Alternative protection such as taped splines will leak and less durable lower perm sheet goods offer little to no drying capacity resulting in water damage and mold.

Higher Perms for Faster Drying - During (and after) Construction


Do You Want 1400 Gallons of Moisture Left in the Building Envelope?

VS Diffusion

SlopeShield Plus SA Mass Timber Deck Protection

  • Resists bulk water intrusion
  • High drying capacity: 30 perms
  • Permanent installation works in conjunction with acoustical mat and concrete topping slab
  • Apply in wet or freezing weather
  • Tough and durable to tools and machinery
  • Excellent traction, slip resistant
  • Six-month UV and climate exposure
  • Monolithically covers seams, splines
  • Integrates with VaproShield’s wall membranes for post/column and beam protection

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SlopeShield Plus SA handles even ponding water, which can be easy swept away during the workday. It monolithically covers seams and splines further protecting the mass timber structure.

Mass Timber Dryable Wall and Roof Protection

CLT DeckProtection WebImage 01 LettersALettersA Protect the vulnerable roof and deck with SlopeShield Plus SA and VaproTape. The high drying capacity continuously dries out the inner wood core layers through vapor diffusion.
LettersA Details matter, protect the end grain of the mass timber with a simple “drip edge” created by overhanging SlopeShield Plus SA.
LettersARough openings are also “holes” for water to penetrate the structure. Safeguard the walls of the mass timber structure by installing PanelShield SA.
LettersABeams and columns need to be temporarily protected during construction. WallShield IT, mechanically attached, offers best in class moisture protection, and is easily removed during the next phase of construction.

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Fast and easy to install, SlopeShield Plus SA will protect the mass timber structure floor or deck by resisting bulk water infiltration, while simultaneously drying out the inner layers of the mass timber.

PanelShield SA for walls withstands up to 12 months UV/climate exposure plus offers a superb drying capacity of 26 perms for continuous mass timber drying.

Durable to foot traffic and heavy equipment, SlopeShield Plus SA can withstand 6 months UV and climate exposure. It evens handles ponding water which can be easily swept away.

End Grain Protection

Water absorption at the end grain (panel edges) is faster than on the horizontal plane of the panel, therefore it is critical to protect the end grain from water absorption.


CLT panel edges absorb water faster than the CLT plane, making end grain protection critical.

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Protecting the panel edge with SlopeShield Plus SA is simply an extension of the deck installation.

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SlopeShield Plus SA Handles ponding water, which is easily swept away directly over the drip edge.

Factory Installation: Easy and Practical

Often CLT panels are shipped simply with loose sheets, offering little to no moisture protection.

SlopeShield Plus SA is easily applied at the factory around the entire panel, offering protection during transport and while being erected.

Mass Timber Protection Resources