zaro

How is exterior wood treated?

Published in Wood Treatment 5 mins read

Exterior wood is treated primarily to protect it from harsh environmental elements, prevent decay, and enhance its aesthetic appeal, significantly extending its lifespan and maintaining its beauty.

Why Treat Exterior Wood?

Treating exterior wood is crucial for its longevity and performance. Without proper protection, wood is vulnerable to a range of damaging factors:

  • Moisture: Rain, snow, and humidity can lead to wood rot, swelling, and warping.
  • UV Radiation: Sunlight causes wood to gray, crack, and become brittle over time.
  • Fungal Decay: Mold, mildew, and fungi thrive in damp conditions, breaking down wood fibers.
  • Insect Infestation: Termites, carpenter ants, and other wood-boring insects can cause significant structural damage.
  • Wear and Tear: Heavy foot traffic on decks or constant exposure to elements can lead to scuffs and degradation.

Common Methods for Treating Exterior Wood

Various treatment options are available, each offering specific benefits regarding protection, appearance, and durability.

Wood Stains and Dyes

Applying wood stain and wood dyes is an excellent way to protect exterior wood while adding rich color. These treatments are formulated to penetrate the wood surface, offering great coverage and long-lasting durability. They help assure the wood is protected from weathering and heavy foot traffic, while enhancing the natural wood grain for a hardwearing and scuff-resistant finish. Stains come in opaque, semi-transparent, and transparent options, allowing varying degrees of wood grain visibility.

  • Benefits: UV protection, water resistance, color enhancement, grain enhancement, durability against traffic.
  • Ideal for: Decks, fences, siding, outdoor furniture.

Wood Preservatives

These treatments are designed to protect wood from rot, decay, and insect infestation, especially for wood in ground contact or high moisture environments. Many modern preservatives are water-based and contain active ingredients like copper compounds.

  • Types:
    • Pressure-treated wood: Wood that has been infused with chemical preservatives under high pressure, making it highly resistant to rot and insects. Common for structural elements, decks, and fences.
    • Topical preservatives: Applied like paint or stain, offering a layer of chemical protection for existing structures.
  • Benefits: Excellent protection against rot, fungi, and insects; prolongs wood life significantly.
  • Ideal for: Deck substructures, fence posts, garden beds, and any wood exposed to severe moisture.

Wood Oils

Natural oils, such as linseed oil, tung oil, or specific deck oils, penetrate deep into the wood fibers, nourishing and protecting them from within. They provide a natural, often matte finish that highlights the wood's natural beauty.

  • Benefits: Enhances natural wood color, prevents drying and cracking, offers water repellency, easy to reapply.
  • Ideal for: Hardwood decks, garden furniture, or surfaces where a natural look is desired.

Exterior Paints

Paint forms an opaque layer on the wood surface, completely covering the grain and providing comprehensive protection against moisture, UV rays, and physical abrasion.

  • Benefits: Wide range of colors, excellent protection against weather, seals the wood completely, easy to clean.
  • Ideal for: Siding, trim, doors, or any area where a specific color and maximum surface protection are desired.

Clear Sealers/Varnishes

These products create a clear, protective film on the wood surface, providing a glossy or satin finish. They are primarily used for UV protection and water repellency, allowing the natural wood color and grain to show through without adding pigment.

  • Benefits: Maintains natural wood appearance, good UV protection, excellent water resistance, durable surface film.
  • Ideal for: Outdoor furniture, doors, or other decorative wood elements where a clear, protective topcoat is preferred.

Choosing the Right Treatment

Selecting the appropriate treatment depends on the type of wood, its exposure to elements, desired aesthetic, and required level of protection.

Treatment Type Primary Benefit Appearance Durability Maintenance
Wood Stains/Dyes UV, water, traffic protection Transparent/Opaque Good Reapply every 2-5 years
Wood Preservatives Rot, insect, fungal protection Varies (often green/brown tint) Excellent Very low, part of initial wood purchase
Wood Oils Prevents drying, water repellency Natural, matte Moderate Reapply annually or bi-annually
Exterior Paints Max weather protection, color change Opaque Excellent Reapply every 5-10 years
Clear Sealers UV, water protection, natural look Clear, glossy/satin Good Reapply every 1-3 years

Factors to Consider:

  • Wood Species: Some woods inherently resist decay more than others and might require less intensive treatment.
  • Exposure: Wood constantly exposed to moisture or direct sunlight needs more robust protection.
  • Desired Look: Do you want to see the wood grain, or prefer a solid color?
  • Maintenance Commitment: Some treatments require more frequent reapplication than others.
  • Traffic Level: High-traffic areas like decks benefit from durable, scuff-resistant finishes.

Application Tips

Proper preparation and application are key to the effectiveness of any exterior wood treatment:

  • Clean the Wood: Ensure the wood surface is free of dirt, mildew, and old finishes. Pressure washing or using a wood cleaner is often recommended.
  • Repair Damage: Fill any cracks or holes and sand rough spots.
  • Ensure Dryness: Apply treatments only when the wood is thoroughly dry to allow proper penetration and adhesion.
  • Follow Manufacturer Instructions: Adhere to recommended application methods, temperature ranges, and drying times.
  • Apply Multiple Coats: Often, two thin coats are better than one thick coat for optimal protection and appearance.

Maintenance

Regular cleaning and inspection of exterior wood are essential to identify any signs of wear or damage early. Reapplication of treatments based on manufacturer recommendations will ensure continuous protection and extend the life of your exterior wood features.