Termite Prevention in New Construction

What It Is

Application of liquid termiticide to soil before and during construction to create a chemical barrier around and under the structure.

When applied:

• Pre-pour: Before concrete slab is poured
• Post-pour: Around foundation perimeter after slab cures
• During framing: Around plumbing penetrations and utility entries
• Final grade: After backfill and final grading

Application Methods by Foundation Type

Slab-on-grade foundations:

• Treat soil under entire slab area
• Treat around perimeter after pour
• Treat around plumbing and utility penetrations
• Apply at grade beam and foundation walls

Crawl space foundations:

• Treat soil under crawl space
• Treat foundation walls (interior and exterior)
• Treat around piers and support posts
• Apply to exposed soil after construction

Basement foundations:

• Treat soil around exterior foundation walls
• Treat under basement slab
• Treat around utility penetrations
• Apply at foundation-wall interface

Common Termiticides Used

• Fipronil (Termidor): Non-repellent, transfer effect, 10+ year protection
• Imidacloprid (Premise): Non-repellent, long-lasting
• Bifenthrin (Talstar): Repellent barrier, 5-7 year protection
• Chlorantraniliprole (Altriset): Low toxicity, effective

Cost: $1,000-2,500 for average home (much less than post-construction treatment)

Documentation Requirements

Keep records of:

• Treatment date and product used
• Application rate and total amount
• Diagram showing treated areas
• Applicator license number
• Warranty information
• Tag or certificate (often required by code)

Why important: Required for warranty, helpful for future sales, may be needed for permits

Termite Shields (Metal Barriers)

What they are: Metal sheets installed between foundation and wood framing to force termites into the open.

Installation:

• Placed on top of foundation before sill plate
• Must extend beyond foundation edge
• Bent downward at 45° angle
• All seams sealed
• Penetrations sealed around pipes/bolts

Pros: No chemicals, permanent, forces visible mud tubes

Cons: Doesn't prevent termites, only makes them visible; installation must be perfect

Cost: $1-3 per linear foot

Mesh Barriers (Stainless Steel)

What they are: Fine stainless steel mesh with openings too small for termites to pass through.

Applications:

• Under slab perimeter
• Around pipe penetrations
• At expansion joints
• In weep holes

Pros: Chemical-free, permanent, effective at penetrations

Cons: Expensive, requires careful installation, not widely available

Cost: $5-15 per linear foot

Basaltic Particle Barriers

What they are: Crushed basalt rock (specific size) that termites cannot tunnel through.

Installation:

• 4-6 inch layer under and around foundation
• Particles must be uniform size (1.7-2.8mm)
• Must remain undisturbed

Pros: Non-toxic, permanent, no maintenance

Cons: Expensive, requires specific particle size, can be disturbed during landscaping

Cost: $3-8 per square foot

Foundation Design

• Monolithic slabs: Fewer joints = fewer entry points
• Proper height: Foundation at least 6 inches above grade
• Exposed foundation: 4-6 inches of visible concrete for inspection
• Seal cracks: Fill all cracks and joints during construction
• Avoid hollow blocks: Or fill cells with concrete/grout

Sill Plate Protection

• Use pressure-treated lumber: ACQ or CA treatment for all sill plates
• Borate treatment: Apply borate to all framing lumber (if allowed by code)
• Proper anchoring: Secure connection to foundation
• Seal gaps: Foam or caulk between sill and foundation

Crawl Space Design

• Adequate height: Minimum 18 inches clearance for inspection
• Ventilation: 1 sq ft vent per 150 sq ft floor area
• Vapor barrier: 6-mil polyethylene over soil
• Access: Easy access for inspection and treatment
• Drainage: Slope away from foundation, install drain if needed

Plumbing and Utility Penetrations

• Minimize penetrations: Group utilities where possible
• Seal all gaps: Use expanding foam or mortar around pipes
• Treat during construction: Apply termiticide around penetrations
• Accessible for inspection: Don't bury or hide penetrations

Structural Wood

• Sill plates: Pressure-treated lumber (required by most codes)
• Bottom plates: Treated lumber for exterior walls
• Rim joists: Consider treated or engineered lumber
• Deck framing: All pressure-treated or composite
• Fence posts: Treated lumber or non-wood alternatives

Learn more: Termite-Resistant Materials

Non-Wood Alternatives

• Steel framing: Termite-proof, consider for high-risk areas
• Concrete block: For foundation and lower walls
• Fiber cement siding: Instead of wood siding
• PVC trim: For exterior trim and fascia
• Composite decking: For decks and porches

Borate-Treated Products

What it is: Wood products treated with borate (boron-based preservative)

Applications:

• All framing lumber (if budget allows)
• Sheathing and subflooring
• Rim boards and headers
• Interior framing in humid climates

Pros: Excellent termite protection, also prevents rot and mold

Cons: More expensive, water-soluble (indoor use only), not all areas allow it

Cost: 10-20% more than untreated lumber

Before Construction Begins

• Clear all wood debris: Remove stumps, roots, lumber scraps
• Grade properly: Slope away from building site
• Remove vegetation: Clear trees/shrubs too close to foundation
• Treat existing infestations: Address termites in nearby structures
• Install drainage: French drains if site is wet

During Construction

• Don't bury wood: Remove all form boards, stakes, scraps
• Keep lumber dry: Store off ground, covered
• Protect treated areas: Don't disturb soil treatment
• Maintain drainage: Keep water away from foundation
• Document everything: Photos of treatments and barriers

International Residential Code (IRC)

Minimum requirements:

• Foundation at least 6 inches above grade
• Clearance between wood and soil (varies by region)
• Pressure-treated wood for sill plates in high-risk areas
• Termite protection in "very heavy" termite zones

Regional variations:

• High-risk areas: May require chemical treatment or physical barriers
• Moderate-risk: Treated sill plates typically required
• Low-risk: Fewer requirements but prevention still recommended

Check with: Local building department for specific requirements

Questions to Ask

• What termite prevention is included in the base price?
• Do you offer pre-construction soil treatment?
• What termiticide do you use? What's the warranty?
• Can I upgrade to borate-treated lumber?
• Will you install termite shields?
• How do you handle wood debris during construction?
• What documentation will I receive?
• Do you have relationships with pest control companies?

Specifications to Include

• Pre-construction soil treatment (specify product)
• Pressure-treated sill plates (specify treatment type)
• Borate treatment for framing (if desired)
• Termite shields at foundation
• Sealed penetrations
• Proper drainage and grading
• Documentation and warranty