šŸš§ PreserveĀ® pressure treated wood | Treated Wood

Real Wood for Your Outdoor Spaces

Proven Long-term Protection

PreserveĀ® is a family of fully-dissolved copper-based wood preservative solutions for exterior wood 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 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 framingĀ 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-CĀ treatment is also available with a built-in water repellent and marketed as PreserveĀ® Plus.

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Pismo Beach Deck Copy
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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.

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 in Canada since 2002.

Preserve ACQ Alkaline Copper Quaternary (ACQ) used as a wood preservative is being replaced with Preserve CA-C or CA-B, prompted by the demand for quaternary needed in cleaning products due to the COVID-19 pandemic.

Both Preserve CA types B and C, are seen as ā€œgreenerā€ 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

  • Unnamed 17

    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 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

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

PPreserve 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 Standardā„¢ (NGBS). Preserve is also formulated with 100% recycled copper.

Preserve CA Green Certified Product Certificate

  • 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 and Preserve ACQ treated wood are 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 and Preserve ACQ Lifetime Limited Warranties for terms and conditions.