Photo: Sealle · CC BY-SA 4.0 · Source
Supply and install rigid polyiso foam board insulation (1-2 in, foil faced) on walls, roof deck or basement, with taped seams and fasteners.
Polyisocyanurate Insulation typically costs $2 to $4.50 per sq ft (national average as of 2026). Most straightforward jobs start near $2 per sq ft. Final pricing depends on material quality, project scope, local labor rates, and site conditions. Use our free calculator below for a personalized estimate.
Quality Level
Estimated Total Cost
200 sq ft • Standard Quality
National average — enter your ZIP for local prices.
Estimates are approximate and vary by location, project scope, and current market conditions. Contact a local contractor for an accurate quote.
$1.70 – $3.83 per sq ft
1-1/2 in. foil-faced polyiso board (around R-9), fastened to the surface, seams taped
$2 – $4.50 per sq ft
1-1/2 in. foil-faced polyiso board (around R-9), fastened with cap fasteners, all seams taped with foil tape
$2.50 – $5.63 per sq ft
1-1/2 in. foil-faced polyiso board (around R-9), fastened, seams taped, edges and penetrations sealed with foam
| Component | Category | Low | High | Unit |
|---|---|---|---|---|
| Materials | material | $0.91 | $2.03 | sq ft |
| Labor | labor | $0.69 | $1.57 | sq ft |
| Supplies & Other | supplies | $0.24 | $0.54 | sq ft |
| Equipment & Disposal | equipment | $0.16 | $0.36 | sq ft |
Supply and install rigid polyiso foam board insulation (1-2 in, foil faced) on walls, roof deck or basement, with taped seams and fasteners.
Typical polyisocyanurate insulation pricing range per sq ft.
Starting price $2 per sq ft. National average as of 2026. This is a directional range. Final pricing depends on scope, materials, access, and local labor rates.
Estimates are approximate and vary by location, project scope, and current market conditions. Contact a local contractor for an accurate quote.
Foil-faced polyiso boards butted at a corner showing the cream foam core
Photo: Sealle · CC BY-SA 4.0 · Source
Find a pro to do thisPolyisocyanurate Insulation usually lands between $2 to $4.50 per sq ft. That range reflects current national calculator data after materials, labor, supplies, equipment, and disposal are rolled together. Your real quote will move based on quantity, site conditions, finish level, and contractor availability in your ZIP code.
Supply and install rigid polyiso foam board insulation (1-2 in, foil faced) on walls, roof deck or basement, with taped seams and fasteners.
Material selections can move the budget faster than anything else, with current material allowances landing around $0.91 to $2.03 per sq ft.
Labor complexity is the next major swing factor, with installation or trade time currently averaging $0.69 to $1.57 per sq ft.
Smaller consumables still matter, because supplies are contributing about $0.24 to $0.54 per sq ft.
Specialty tools, access equipment, cleanup, and disposal can add another $0.16 to $0.36 per sq ft.
Scope changes, premium finishes, difficult access, demolition, and permit requirements can push the total toward the high end of the range. Cleaner access, standard finishes, and bundled work often keep the job closer to the low end.
Get multiple itemized bids, ask contractors to separate materials from labor, and confirm what is included before you compare totals. Scheduling during a slower season and bundling adjacent work can also reduce mobilization costs.
Keep specifications tight before work starts. Change orders are one of the fastest ways to blow past the original budget, especially when material lead times or specialty trades are involved.
DIY can make sense when you already own the tools, understand the prep requirements, and can tolerate schedule risk. Hiring a pro is usually the better move when mistakes would affect finish quality, code compliance, waterproofing, structural performance, or warranty coverage.
View local pricing for polyisocyanurate insulation across 51 states.
Find contractors who list this service and ask for a written quote.
Cost guides for property owners. Contractor ID for the shops who do the work.
Foil-faced polyiso boards laid with rebated edges meeting at a right angle
Photo: Sealle · CC BY-SA 4.0 · Source
Find a pro to do thisUse the calculator range of $2 to $4.50 per sq ft as your baseline, then compare that against the time, tool rentals, material waste, and rework risk you would take on by doing the project yourself.
Most polyisocyanurate insulation jobs start with site review, measurements, and material confirmation. From there the crew usually handles preparation, core installation or repair work, cleanup, and a final walkthrough to confirm the finished scope matches the quote.
Ask each contractor how they handle protection of adjacent finishes, debris removal, and change approvals. Those three points tend to separate a clean project from an expensive headache.