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Innovative warm brown colour and an environmentally preferable treatment process create a distinctive option for outdoor projects.

Top 10 questions

What is MicroPro Sienna®?

MicroPro Sienna is wood pressure treated with MicroPro® Micronized Copper Azole, a registered wood preservative in the CSA Standards. Micronized iron oxide pigments added during pressure treatment give the wood a warm brown colour. Read More

Where can it be used?

MicroPro Sienna can be used in residential applications (decks, fences, fresh water docks and landscaping) above ground, in ground contact and in freshwater contact. Usage is indicated on the end tag attached to the treated lumber. Read More

How long will the colour last?

Left unprotected, the warm brown colour of Sienna will fade to a soft tan or beige and transition to grey over time. The length of time will vary according to the exposure to sunlight, the wood species and the application. This transition can be slowed by application of a semi-transparent stain or a water repellent with added toner after installation to provide resistance to weathering and UV exposure. Read More

How do I protect/maintain the colour of my MicroPro Sienna project?

A wide range of wood finish products on the market have been formulated for exterior wood care. We suggest speaking to your local building materials supplier. It is our experience that a Sienna dealer can tell you what other customers have used successfully. As a general rule, you need pigments or colour in the product to protect the wood surface against UV. Always read the finish product label and follow the manufacturer’s recommendations on how and when the product should be applied. Read More

When can I apply a finish to my MicroPro Sienna project?

Waiting a year or “a season” before applying a finish is a bit of misinformation about treated wood that has been circling around retail yards and contractors for some time. Unless the coating manufacturer stipulates otherwise, you can apply a stain or water repellent to the wood as soon as it is dry to the touch, which may be as soon as two weeks or as long as eight or more. It will depend on the weather, the exposure to sunlight and how wet the wood was when it was installed (it is saturated with water during pressure treatment). To test that the treated wood is surface dry, sprinkle water droplets on the surface. If the water droplets are absorbed into the wood, it is ready for stain. If not, try sprinkling again in a few days. When you apply a protective finish be sure to follow the manufacturer’s recommendations, especially on how and when it should be applied. Read More

Do I need to protect the cut ends of boards?

Yes. When building your outdoor project with pressure treated wood it is important to protect the cut ends, large drill holes, and other field cuts. Failure to do so will void the product warranty.

  • For pressure treated timbers and for pressure treated wood used in ground contact applications, a brush on end-cut wood preservative is required at the time of construction on all saw cuts, large drill holes and other field cuts. Two applications of a copper naphthenate based end-cut preservative must be applied to the treated wood before it is installed. Follow the manufacturer’s directions for proper application.
  • For pressure treated wood used in above ground applications, such as deck boards, railings, post tops or fence boards, a brush on end-cut wood preservative or Timber Specialties Cut-N-Seal® product should be applied to all saw cuts, large drill holes and other field cuts at the time of construction. Follow the manufacturer’s directions for proper application. Read More
Do I need to use a specific type of fastener for my MicroPro Sienna project?

MicroPro Sienna treated wood is no more corrosive to fasteners than untreated wood. Use exterior fasteners and hardware that are in compliance with the manufacturer’s recommendations and the building codes for their intended use. Read More

Can aluminum building products be used with MicroPro Sienna?

Yes. Aluminum building products may be placed in direct contact with MicroPro Sienna Treated Wood used indoors or in above ground exterior applications where the wood is not exposed to frequent and prolonged wetting, such as decks and fencing. MicroPro Sienna Treated Wood in direct contact with aluminum products should only be used in code compliant construction applications that provide proper water drainage and do not allow the wood to be exposed to, or remain in contact with a continual moisture source, standing water or water immersion, such as boat docks, hot tubs and swimming pools. In addition, MicroPro Sienna Treated Wood should not be encased, sealed, or wrapped with aluminum products where moisture or water can be trapped, so as to avoid pitting or other undesirable results. Read More

Does MicroPro Sienna have any environmental certifications?

The MicroPro micronized copper technology used in MicroPro Sienna Treated Wood process is setting a new benchmark in environmental standards for wood preservation. MicroPro was the first, and is the only, wood treatment process to be certified as an Environmentally Preferable Product (EPP), by Scientific Certification Systems (SCS), based on Life-Cycle Assessment. Wood products treated with MicroPro technology are eligible for more green building points toward NGBS Green Certification than other treated wood. UL GREENGUARD GOLD Certification indicates that MicroPro preservative technology has undergone rigorous testing and has met stringent standards for low volatile organic compound (VOC) emissions. Products certified to this criteria are suitable for use in schools, offices, and other sensitive environments. Read More

What is the green colouring on MicroPro Sienna Treated Wood?

On some MicroPro Sienna treated wood a green colour may appear along the grain of the wood and around knots of some wood species. This green colour is due to the copper that is used in the wood preservative system. Over time the green colour will change to a tan colour that blends into the overall tone of the wood. Read More

MicroPro Sienna Treated Wood products are produced by independently owned and operated wood preserving facilities.
MicroPro, MicroPro Sienna, and Cut-N-Seal are registered trademarks of Koppers Performance Chemicals Inc.