Termite-Resistant Building Materials

Pressure-Treated Lumber

What it is: Wood infused with chemical preservatives under pressure to resist decay and insects.

Common treatments:

• ACQ (Alkaline Copper Quaternary): Copper-based, effective against termites
• CA (Copper Azole): Lower copper content, good termite resistance
• Borate-treated: Excellent termite resistance, indoor use only (water-soluble)

Best uses:

• Foundation sill plates
• Deck framing and posts
• Fence posts
• Ground-contact applications

Pros: Affordable, widely available, proven effectiveness, looks like natural wood

Cons: Not 100% termite-proof, requires maintenance, chemicals may leach over time

Cost: 20-40% more than untreated lumber

Naturally Resistant Woods

Species with natural resistance:

• Redwood (heartwood): High natural resistance
• Cedar (heartwood): Good resistance, aromatic oils deter termites
• Cypress: Moderate to good resistance
• Teak: Excellent resistance but expensive

Important notes:

• Only heartwood is resistant; sapwood is vulnerable
• Resistance decreases as wood ages and weathers
• Not immune—termites will attack if no alternatives available

Best uses: Siding, trim, outdoor furniture, decking (non-structural)

Cost: 2-5x more than standard lumber

Composite Decking

What it is: Mixture of wood fibers and plastic (polyethylene or PVC)

Termite resistance:

• High plastic content = better resistance
• Some termites will still attack wood fiber content
• Not completely termite-proof but much better than solid wood

Pros: Low maintenance, doesn't rot, consistent appearance, long lifespan

Cons: Higher upfront cost, can fade, may feel hot in sun, limited structural use

Best uses: Deck boards, railings, trim

Cost: $3-8 per square foot (vs. $1-3 for wood decking)

Fiber Cement Siding

What it is: Cement, sand, and cellulose fibers formed into boards

Termite resistance: Excellent—termites cannot digest cement

Pros: Fire-resistant, rot-resistant, paintable, looks like wood, durable

Cons: Heavy, requires special tools to cut, professional installation recommended

Best uses: Exterior siding, trim, soffits

Cost: $5-10 per square foot installed

Engineered Wood Products (with caution)

Types: Plywood, OSB, LVL, I-joists

Termite resistance: Generally poor unless specially treated

Considerations:

• Glues and resins don't deter termites
• Some products available with borate treatment
• Keep away from soil contact
• Use in dry, protected locations only

Steel Framing

Termite resistance: Complete—termites cannot eat metal

Pros: Termite-proof, fire-resistant, doesn't warp or rot, consistent dimensions

Cons: Thermal bridging issues, requires special tools, higher labor cost, rust potential

Best uses: Framing in high-risk areas, commercial buildings, additions

Cost: 15-30% more than wood framing

Concrete & Masonry

Termite resistance: Excellent—termites tunnel around but don't damage

Applications:

• Concrete block foundations
• Poured concrete foundations
• Concrete slab floors
• Brick or stone veneer

Important: Seal cracks and joints—termites can pass through gaps as small as 1/32 inch

PVC & Vinyl

Termite resistance: Complete—pure plastic, no food value

Applications:

• PVC trim boards
• Vinyl siding
• PVC decking (100% plastic)
• Window and door frames

Pros: Never needs painting, won't rot, termite-proof, low maintenance

Cons: Can look artificial, expands/contracts with temperature, limited structural use