Real Wood for Your Outdoor Spaces

Proven Long-term Protection

Preserve® is a family of fully-dissolved copper-based wood preservative solutions for exterior treated lumber products. Preserve formulations provide long-term protection from fungal decay and termite attack for a wide variety of residential, commercial and agricultural construction projects including above-ground, ground contact, fresh-water immersion, and salt-water splash treated wood applications.

In the US and other countries, CA-C and CA-B are registered for use on: lumber, timbers, landscape ties, fence posts, building and utility poles, land, freshwater and marine pilings, seawalls, decking, wood shingles, and other wood and wood framing structures.

The Preserve treatment lends a distinctive green tint to the timber, although an additional color pigment, DesignWood, can be introduced during the treatment process to stain the wood in shades of brown.

Preserve CA-C treatment is also available with a built-in water repellent and marketed as Preserve® Plus.

Porch Deck Girls With Checkers Landscape Low Res
Pismo Beach Deck Copy
Tahoe Meadows People Walking 401Kb

Preserve CA

Preserve CA - Copper Azole Type C (CA-C) is found readily across the US and Copper Azole Type B (CA-B) in Canada. Please watch our informative videos below to learn more about this treated lumber preservative.

The CA-C preservative formulation is made of 96.1 % soluble copper (100% recycled) and organic triazole co-biocides; tebuconazole and propiconazole, which help control copper-tolerant fungi. Preserve CA is widely used across the US.

The CA-B, copper azole Type B, formulation is very similar, also made of 96.1% 100% recycled, soluble copper and 3.7% tebuconazole. Preserve CA-C has been registered for use as a treated lumber preservative in Canada since 2002.

Both Preserve CA types B and C, are seen as “greener” preservatives and a more sustainable option than previous wood preservatives. Both are also certified by Home Innovation Research Labs for points toward NGBS Green Certification to the ICC 700 National Green Building Standard.

Product Applications

Preserve CA

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    Above Ground Exposed Use

  • Western Species Brown Fence Dw

    Ground Contact General Use

  • Dock Lake

    Fresh-water Immersion

  • Pismo Beach2

    Salt-water Splash

The Qualities That Matter to You

Dock Lake

Ideal for residential, commercial and certain agricultural projects in these treated lumber applications:

  • Above Ground Exposed Use
  • Ground Contact General Use
  • Fresh-water Immersion and Salt-water Splash

Preserve CA-C pier over ocean sand dunes

  • Field-tested, proven-to-last, and accepted as an industry standard
  • Building code compliant - IRC, IBC, and National Building Code of Canada (NBCC)
  • American Wood Protection Association (AWPA) standardized wood preservatives
  • Canadian Standards Association (CSA) approved
  • Parks Canada approved
  • Home Innovation NGBS Green Certified - Preserve CA
  • Formulated with 100% recycled copper

3 Pier Poles With Birds

Preserve CA treated wood is covered by a Lifetime Limited Warranty against damage from fungal decay or termite attack when installed in accordance with applicable building codes. See Preserve CA (US) and Preserve CA (Canada) Lifetime Limited Warranties for terms and conditions.

BAAC Viance logo copy

Preserve CA-C and Preserve CA-B meet the criteria to qualify for the Buy American Act Certification.

This letter serves as compliance certification that Viance preservatives for the Preserve CA-C and Preserve CA-B brands are manufactured in the United States and meet the requirements of the Buy American Act.

Download a copy of Viance's BAA letter of compliance here.

Preserve CA is an NAHB Home Innovation Research Labs Green Certified Product for Resource Efficiency and is eligible to contribute points towards building certification under the National Green Building Standard™ (NGBS). Preserve is also formulated with 100% recycled copper.

Preserve CA Green Certified Product Certificate

Green Building Points for Viance products

  • Always use building-code approved, corrosion-resistant fasteners and connectors that are suitable for use in pressure-treated wood.
  • Recommended Fasteners: use hot-dipped galvanized fasteners (meeting ASTM A 153) or stainless steel.
  • Recommended Connectors: use G185 hot-dipped galvanized for exterior applications.
  • For Permanent Wood Foundations and corrosive environments, such as Coastal areas with saltwater spray, use code approved stainless steel fasteners and connectors.
  • Preserve is not suitable for direct contact with uncoated steel or aluminum building products.


Preserve CA (copper azole) treated wood is covered by a Lifetime Limited Warranty against damage from fungal decay or termite attack when installed in accordance with applicable building codes. See the Preserve CA Lifetime Limited Warranty for terms and conditions.