Below is a concise, practical guide to the typical costs and cost drivers for adding fire‑resistant coatings to building elements (steel, wood, concrete). I'll give typical unit cost ranges, what affects price, an example estimate, and suggestions to get accurate bids.

Summary cost ranges (ballpark, U.S. dollars)

• Intumescent paint for structural steel (creates an insulating char during fire): roughly $2.00 to $12.00 per sq ft of coated surface (most common projects fall in $3–$8/ft²). Higher end for thicker ratings (2–3 hours), complex shapes, or premium systems.
• Cementitious (spray-applied) fireproofing for steel/concrete: roughly $1.50 to $6.00 per sq ft of protected surface (typical $2–$4/ft²). Thickness and required hourly rating drive price.
• Fire‑retardant coatings for wood (spray or brush applied): roughly $0.50 to $3.00 per sq ft of exposed surface (varies by product, number of coats, and finish requirements).
• Intumescent coatings for concealed wood/architectural trim (higher performance/appearance): $3.00 to $10.00 per ft².
• Specialty epoxy/ceramic fire coatings for equipment or tanks: highly variable — often $5 to $25+/ft² depending on operating conditions.

What these ranges include (and what they typically exclude)

• Included: materials, standard surface preparation (cleaning, light abrasive), application labor by trained crews, typical number of coats to meet a given rating, normal cure times.
• Often excluded: extensive surface repair or removal (rust removal, replacing corroded steel), heavy grit blasting, scaffolding or hoisting beyond a minimal setup, fire testing/certification beyond product data, permit fees, project mobilization for small jobs (which increases per‑ft² cost), and finish painting to meet architectural color/texture requirements.

Primary cost drivers

• Required fire‑resistance rating (e.g., 1‑hour vs 2‑hour vs 3‑hour): higher ratings need thicker systems or specialized products → higher costs.
• Substrate type and condition: clean, smooth concrete/steel is cheapest to coat; corroded or irregular surfaces require more prep and materials.
• Access and logistics: heights, confined spaces, need for scaffolding, lifts, or rope access raise labor and equipment costs.
• Area and project scale: small jobs have higher unit prices due to mobilization/minimums; larger contiguous areas lower per‑ft² cost.
• Aesthetic requirements: coatings that must be sanded and top‑coated for appearance add cost.
• Local labor rates and regional product availability.
• Code/testing/certification needs: some projects require UL/ASTM-listed assemblies, documentation, third‑party inspection.

Example budget calculation (illustrative)

• Project: coat 1,000 ft² of exposed structural steel to achieve 1‑hour protection using a mid-range intumescent system.
  • Material & application (mid-range): $5/ft² × 1,000 ft² = $5,000
  • Surface prep & minor repairs: $800
  • Scaffolding / lifts (shared, short duration): $700
  • Project management / small mobilization fee: $500
  • Total ≈ $7,000 → $7.00/ft² overall

For cementitious spray fireproofing on 5,000 ft² for 2‑hour rating:

• $3.00/ft² × 5,000 = $15,000 (materials + application typical)
• Add allowances for access, patching, and waste → budget ~$16,500–$18,000 total.

How to get an accurate price for your job

• Identify the required fire‑rating (hours) and the substrate(s) to be protected.
• Ask for bids from 2–3 contractors who are experienced with fireproofing and can show UL/ASTM listings and project references.
• Require proposals to include: surface prep scope, manufacturer and product data (with tested hourly rating), total sq ft applied, number of coats/thickness, cure times, warranty, and any required inspections.
• Confirm whether scaffolding, contractor insurance, permits, and third‑party inspection/acceptance are included.
• For structural steel, prefer applicators certified by the coating manufacturer or structural fireproofing trade organizations.

Regulatory / testing notes

• Many jurisdictions require products/assemblies tested to ASTM E119 or UL 263 and documentation of “fire‑resistance rating.” Verify local building code and AHJ (authority having jurisdiction) expectations.
• Some products require periodic inspection or maintenance to retain performance — ask for service recommendations.

Ways to reduce cost

• Bundle larger contiguous areas into a single contract to lower mobilization overhead.
• Do preparatory repairs or rust removal where economical before contractor mobilizes.
• Choose lower‑profile systems where allowable (e.g., cementitious vs high‑build intumescent) if aesthetics aren’t critical.
• Get competitive bids and prefer contractors who will provide fixed‑price scopes tied to tested systems.

If you want, I can:

• Help estimate a project cost if you give: substrate (steel/wood/concrete), total SqFt to coat, required fire‑rating (1‑, 2‑hour, etc.), and whether access/scaffolding will be needed.
• Provide wording for an RFP (scope of work checklist) to send to fireproofing contractors.