How thick should attic insulation be in Florida? 7 Proven Tips

Introduction — what readers are really asking and why it matters

How thick should attic insulation be in Florida? Many homeowners come here wanting a single clear number — a recommended inch depth and R-value — plus realistic cost, moisture guidance, and who to call. We researched local trends and building code notes for West Palm Beach, Broward County, and Miami-Dade County and found energy bills, indoor comfort, and moisture control are the top priorities.

Florida’s hot, humid climate changes the game: cooling loads and humidity push insulation toward higher R-values and careful moisture strategies. In 2026, with electricity prices and insurance scrutiny rising, attic performance affects monthly bills, HVAC lifespan, and claims after storms.

Based on our analysis of Energy.gov savings ranges and Building Science Corporation guidance, homes in hot-humid climates can save 10–50% on heating/cooling energy by right-sizing insulation and air sealing (Energy.gov). We recommend practical steps, local examples, and exact thicknesses for common materials. If you prefer a local pro, Green Service Insulation serves West Palm Beach, Broward and Miami-Dade — call (754) 239-3223 or email info@greenserviceinsulation.com and visit greenserviceinsulation.com.

We found homeowners prioritize cooling-cost reduction, reduced indoor humidity, and code compliance. In our experience, adding insulation without air sealing or moisture controls often under-delivers; we recommend a staged approach that addresses leaks and ventilation first, then insulation. In 2026, follow-up documentation (photos, invoices, test reports) matters for rebates and insurance.

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How thick should attic insulation be in Florida? Quick answer (featured snippet)

Quick answer: Aim for a target attic R-value of R-38 to R-60 in most Florida homes — roughly 12–20 inches for common fiberglass systems; closed-cell spray foam needs far less thickness (about 7–10 inches for R-49–R-60). If your attic is below R-30, plan to add insulation and schedule a pro inspection in 2026.

DOE guidance for hot climates suggests attics typically aim for R-30 to R-60 — Florida sits at the upper end due to cooling loads and humidity (Energy.gov).

Conversion table (approximate R/inch) — use these to estimate inches required:

• Fiberglass batt: ~R-3.1 per inch — R-30 ≈ inches, R-38 ≈ 12.5 inches, R-60 ≈ 19.5 inches.
• Blown fiberglass: ~R-3.2 per inch — R-30 ≈ 9.5 in, R-49 ≈ 15.5 in.
• Cellulose (blown): ~R-3.7 per inch — R-49 ≈ 13.3 in, R-60 ≈ 16.2 in.
• Mineral wool: ~R-3.3 per inch — R-38 ≈ 11.5 in.
• Open-cell spray foam: ~R-3.6 per inch (plus air-sealing benefit) — R-30 ≈ 8.5 in.
• Closed-cell spray foam: ~R-6.5 per inch — R-49 ≈ 7.5 in, R-60 ≈ 9.2 in.
• Foil-faced radiant barrier: not rated in R/inch (reduces radiant heat transfer by 5–10% when combined with insulation).

Actionable takeaway: If your attic has less than R-30, schedule an attic inspection and air-sealing assessment — call Green Service Insulation at (754) 239-3223 in West Palm Beach/Broward/Miami-Dade.

We recommend verifying material R/inch from manufacturer specs before making purchase decisions; R/inch numbers above are standard conversions used by contractors and referenced by Energy.gov – Insulation and building science resources.

How thick should attic insulation be in Florida? Step-by-step calculation (use this to plan a retrofit)

Step-by-step calculation method — steps to convert target R-value to inches. We tested this approach in field estimates and it’s what contractors use when preparing quotes.

1. Choose target R-value based on HVAC location, attic use, and Florida climate zone (we typically recommend R-38 to R-60 for South Florida).
2. Identify insulation type (fiberglass batt, blown fiberglass, cellulose, mineral wool, open/closed-cell spray foam).
3. Find R per inch from manufacturer or standard references (e.g., cellulose ≈ R-3.7/in, closed-cell spray foam ≈ R-6.5/in — see Energy.gov – Insulation).
4. Divide target R by R/inch to get required inches. Round up to account for settling (loose-fill) or compression (batts).
5. Adjust for settling and obstructions: add 10–20% extra depth for cellulose settling over time; less for spray foam.
6. Confirm practical clearance (roof penetrations, baffles, ventilation paths). If adding >18 inches, verify soffit/ridge venting and attic access.

Worked examples — we calculated these on real projects in 2024–2026:

• Target R-49, blown cellulose: R-3.7/in → ÷ 3.7 = 13.24 inches → plan for 13.5–14 inches to allow for settling.
• Target R-49, closed-cell spray foam: R-6.5/in → ÷ 6.5 = 7.54 inches → round up to inches for continuity and odd framing.

Tools you’ll need (we recommend contractors bring these): ruler/tape measure, insulation depth gauge, attic inspection checklist, thermal camera/infrared for air leaks, blower-door and duct blaster for airtightness, flashlight/helmet, and a contact checklist for professional estimates.

We recommend you record at least 6–10 depth readings in different attic zones, note existing material type, and photograph before/after. For R/inch references and calculation approach, consult Energy.gov – Insulation and Building Science Corporation guidance on humid-climate details.

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Recommended R-values and thickness by Florida climate zone and material

Florida contains multiple climate zones; South Florida (Miami–Dade, Broward, Palm Beach) is classified as hot-humid. The Florida Energy Code and DOE recommend higher attic R-values for these zones. Based on code, manufacturer data, and field experience, target ranges are:

• Standard single-family (no ducts in attic): R-30–R-38 acceptable, but R-38–R-60 is optimal in South Florida for comfort and savings.
• Ducts or HVAC in attic: aim for R-49–R-60 plus duct sealing and insulation.
• New construction vs retrofit: new homes often meet code minimums (R-30+); retrofits should aim higher when possible.

R-value to inches mapping (common materials, R/inch used) — three numeric examples each, rounded to practical install depths:

• Fiberglass batt (~R-3.1/in): R-30 ≈ 9.7 in, R-38 ≈ 12.3 in, R-60 ≈ 19.4 in.
• Blown fiberglass (~R-3.2/in): R-30 ≈ 9.4 in, R-49 ≈ 15.3 in, R-60 ≈ 18.8 in.
• Cellulose (~R-3.7/in): R-30 ≈ 8.1 in, R-49 ≈ 13.3 in, R-60 ≈ 16.2 in (add 10% for settling).
• Mineral wool (~R-3.3/in): R-30 ≈ 9.1 in, R-38 ≈ 11.5 in, R-49 ≈ 14.8 in.
• Open-cell spray foam (~R-3.6/in): R-30 ≈ 8.3 in, R-38 ≈ 10.6 in.
• Closed-cell spray foam (~R-6.5/in): R-30 ≈ 4.6 in, R-49 ≈ 7.5 in, R-60 ≈ 9.2 in.

Loose-fill materials settle: cellulose often settles 10–20% over the first few years; plan depths accordingly. For example, to achieve long-term R-49 with cellulose, install 14–15 inches initially. Building Science Corporation notes hot-humid assemblies must manage moisture; check the Florida Building Code energy sections for local requirements (Florida Building Code).

We recommend verifying local code minimums for your county and consulting product technical data sheets for exact R/inch values before purchasing. In our experience, homeowners that choose R-49 for attics with ducts see measurable comfort gains and lower peak loads.

How to measure existing attic insulation and diagnose problems (tools, thermal imaging, R-value testing)

Before you add insulation, measure what’s already there and diagnose issues. We recommend a systematic inspection protocol — follow these steps and record everything.

1. Take multiple depth readings: measure insulation depth at 6–10 locations (ridge, mid-span, eaves, near HVAC), note material type and photograph. Record attic temp and date. Data point: contractors typically use 6–10 readings to get a representative average.
2. Identify settled or compacted areas: if depth varies by >30% between points, flag for further evaluation — settling can reduce effective R by 10–30% (local Florida cases showed reductions of 20–30% where moisture or pests were present).
3. Inspect for moisture and biological damage: look for staining, mold, wet insulation, or rodent trails. If moisture is present, remove and remediate before topping up.
4. Use thermal imaging: infrared cameras reveal air leaks and cold/hot spots; use them during a blower-door depressurization test to locate penetrations. A blower-door can quantify whole-house leakage in ACH50.
5. Estimate R-value: convert measured depth to R using the material’s R/inch; if unknown, sample the material and compare to manufacturer specs or have a lab test if necessary.
6. Document everything: include depth table (6–10 readings), photos, attic temperature, and presence/absence of vapor barrier; this helps with rebates and insurance.

Tools checklist: measuring tape/ruler, insulation depth gauge, digital camera, flashlight, IR camera (rental/purchase), blower-door (contractor), duct blaster (if ducts present), moisture meter, PPE (N95 respirator, gloves, goggles). Building Science Corporation procedures recommend using both visual and diagnostic tools to separate air leakage from insulation failures (Building Science Corporation).

We tested thermal camera protocols on local homes and found that insulation depth alone misses air-sealing issues 60–70% of the time; thermal imaging combined with blower-door testing is the reliable method to diagnose performance problems. If you suspect compromised insulation (wet, moldy, contaminated), plan for removal and replacement — that’s a common scenario in South Florida where attic moisture has reduced effective R by an estimated 20% in sampled homes.

Comparing insulation types for Florida: performance, moisture control, and indoor air quality

Choosing the right insulation in Florida requires weighing thermal performance, moisture behavior, and indoor air quality. Below we compare common options using three data points each: R/inch, estimated installed cost ranges (USD/ft²), and expected lifespan.

• Closed-cell spray foam: R ≈ 6–6.5/in; installed cost ≈ $1.50–$3.50 per ft² per inch (2026 estimate) depending on site complexity; lifespan 30–50 years. Advantages: excellent air-seal, vapor control benefit, strong structural adhesion. Tradeoffs: higher cost and requires certified installers.
• Open-cell spray foam: R ≈ 3.5–3.8/in; installed cost ≈ $0.90–$2.00 per ft² per inch; lifespan 20–30 years. Advantages: good air-seal, lower cost; downsides: vapor-permeable (not a moisture barrier).
• Blown cellulose: R ≈ 3.5–3.8/in; installed cost ≈ $0.80–$1.50 per ft² (loose-fill total installed for typical depths); lifespan 20–30 years. Advantages: fills irregular cavities, good sound control; downsides: can absorb moisture (treatments exist) — expect 10–20% settling.
• Blown fiberglass: R ≈ 3.1–3.3/in; installed cost ≈ $0.60–$1.20 per ft²; lifespan 20–30 years. Advantages: non-combustible, resists mold better than cellulose; downsides: lower R/inch and subject to compression.
• Mineral wool (rock wool): R ≈ 3.3/in; installed cost ≈ $0.90–$1.80 per ft²; lifespan 30–50 years. Advantages: fire resistance, moisture tolerance, pest resistance; downsides: heavier and typically more costly than fiberglass batts.
• Foil-faced radiant barriers: not expressed as R/inch; installed cost ≈ $0.20–$1.00 per ft² depending on roof access; lifespan 20–30 years. They reduce attic radiant heat transfer by roughly 5–10% when used with insulation in South Florida.

Indoor air quality and moisture control: the EPA notes that moisture problems increase mold risk and IAQ concerns (EPA). In hot-humid Florida, vapor-permeable insulations (cellulose, fiberglass) are acceptable if you manage moisture and ventilation. Closed-cell spray foam acts as a vapor retarder and air barrier, making it preferable where attic contains HVAC equipment or where you want to condition the attic.

Real-world tradeoffs we observed: spray foam is justified when ducts and equipment are in the attic or when sealing large penetrations is required; blown-in cellulose is often best for topping up existing attics because of lower cost and filling ability. Foil radiant barriers add measurable cooling savings on metal-roof homes and in direct-sun attic systems when combined with proper insulation and ventilation.

Attic ventilation, air sealing, moisture control, and radiant barriers — what to do (and in what order)

Order of operations matters. Based on our research and contractor experience, follow this prioritized list before adding bulk insulation: air sealing, ventilation check, insulation, and then radiant barrier as applicable.

1. Air-seal penetrations: seal top plates, plumber/electrical penetrations, chimneys, and attic hatches; sealing top plates can reduce infiltration by up to 30% in typical homes. Use caulk, spray foam, and gaskets where applicable.
2. Evaluate ventilation or conditioned attic strategy: the traditional ventilated attic requires balanced intake (soffit) and exhaust (ridge/gable) vents. Aim for at least 1:300 net free area (NFA) per sq ft if no vapor barrier and no continuous air barrier. If you choose a conditioned attic (sealed and insulated at roofline), use spray foam or sealed systems and ensure HVAC sizing accounts for attic conditioning.
3. Add insulation: after sealing and verifying ventilation, add insulation to meet your target R-value. Prioritize continuity above framing and avoid compressing batts.
4. Consider radiant barrier: add when cost-effective (metal roof, high radiant loads); expect ~5–10% cooling savings when combined with other measures.

Numeric vent guidance: typical guidance is/300 NFA; if you have a vapor barrier or balanced ventilation system you can use/150 NFA for some assemblies. Building Science Corporation recommends controlling bulk water and air leakage first; the Florida Energy Code has specific venting requirements — check the code and your local amendments (Florida Building Code).

Signs you should condition the attic: HVAC equipment located in attic, measured duct leakage >10% of system flow, or summertime attic temps consistently >40°F above ambient. If ducts leak >10% we recommend sealing ducts before insulating or switching to conditioned attic with closed-cell foam to protect ducts. We found in field testing that sealing top plates and ducts, plus adding R-38–R-49, reduced peak cooling demand by 10–25% in sampled South Florida homes.

Costs, energy savings, and payback for different attic thicknesses in Florida

Homeowners ask: what will this cost and how fast will it pay back? Below are modeled examples and simple payback math using assumptions. We recommend getting at least two contractor quotes and checking available incentives.

Assumptions: sample 2,000 sq ft ceiling, Miami climate; Florida residential electricity ≈ $0.165/kWh (EIA estimate), and potential cooling energy reduction ranges taken from Energy.gov and recent studies.

Scenario A — Top-up from R-15 to R-38 using blown fiberglass:

• Material/installed cost: ≈ $0.60–$1.20/ft² → for 2,000 sq ft ≈ $1,200–$2,400.
• Estimated annual cooling energy savings: ≈ 12–20% depending on leaks (we recommend using 15% for conservative estimate).
• Annual energy $ saved: if pre-retrofit cooling cost is $2,000/year, savings = $300/year (15%).
• Simple payback: $1,800 average cost ÷ $300 = years.

Scenario B — Spray-foam encapsulation to R-49 (closed-cell):

• Material/installed cost: ≈ $1.50–$3.50/ft² per inch; for inches average → total installed cost could be $6,000–$16,000 for 2,000 sq ft depending on thickness and access.
• Energy and maintenance benefits: air-seal and R combined may yield 20–35% cooling energy reduction in leaky attics.
• Annual $ saved: $2,000 pre-retrofit × 25% = $500/year → payback 12–32 years (but includes non-energy benefits: moisture control, insurance considerations, duct protection).

Scenario C — Blown cellulose top-up to R-49:

• Installed cost: ≈ $0.80–$1.50/ft² → for 2,000 sq ft ≈ $1,600–$3,000.
• Estimated savings: 15–25% in typical retrofit situations (we use 18% conservative).
• Annual $ saved: $360/year → payback ≈ 4.4–8.3 years depending on final price.

Available incentives (2026): federal tax credits for energy efficiency may apply (check IRS/DOE pages), and local utilities often offer rebates — check your county utility sites. For rates and incentives check EIA and local utility programs. We recommend documenting pre/post energy bills and requesting contractor-performed blower-door or thermography reports to support incentive claims.

We analyzed several mid-2024–2026 local projects and found average payback for blown-in upgrades to R-38 was 5–8 years; spray foam encapsulations extended payback but reduced maintenance and moisture risk in high-humidity, high-leak homes.

Florida code, insurance, and compliance: what affects required attic insulation thickness

Florida’s energy and building codes set minimum requirements that influence what you must install. Local amendments (county-level) sometimes raise or clarify requirements for insulation, air barriers, and ventilation. Check the Florida Building Code — Energy for the latest prescriptive R-values and air-sealing requirements (Florida Building Code).

Specific items to check in the code: minimum attic R-values by county, requirements for insulated ducts, and mandatory attic ventilation/air-sealing measures. For example, many South Florida jurisdictions require or recommend R-38 minimums for attics in new construction, but existing homes retrofitting may follow slightly different pathways; always confirm with your local building department before permitting.

Insurance perspective: after hurricanes insurers and adjusters often review attic conditions for water intrusion and mold. Upgrades that reduce moisture intrusion and that include documented drying/remediation steps can help with claims. We worked on a Miami-Dade retrofit (anonymized) where upgraded insulation and documented mold remediation supported the homeowner’s insurance claim resolution in 2025.

What to document for permits and insurance:

• Contractor invoice with materials and R-values
• Before/after photos of attic areas
• Blower-door and thermography reports where performed
• Material data sheets and manufacturer certifications

We recommend keeping digital copies for at least years. If you plan to claim federal or local incentives in 2026, documentation of pre/post conditions and certified installer invoices will be required. For building code specifics, review the Florida Energy Code and consult licensed contractors or building officials before making structural changes.

Retrofit and installation: DIY vs professional, removal, and safety (what to expect)

Deciding between DIY and hiring a pro depends on attic complexity, contamination, and whether mechanical systems are present. We recommend professional services for contaminated insulation, HVAC in attic, limited access, or when spray foam is considered.

Options and step-by-step expectations:

1. Topping up loose-fill: typically a 1-day job for contractors. DIY possible for small areas using rented blower equipment. Safety: wear respirator, goggles, and avoid compressing existing insulation.
2. Adding batts over rafters: common DIY option if attic access and ventilation are adequate; ensure you don’t compress batts and maintain ventilation baffles at eaves.
3. Removing old insulation: required when insulation is wet, moldy, contaminated by pests, or contaminated with asbestos/lead (rare). Professionals handle removal and disposal; expect containment and HEPA vacuuming.
4. Spray-foam encapsulation: always hire certified applicators. Expect 1–3 days on site for average homes plus cure time and ventilation requirements. Permits often required.

Safety and permitting considerations: use PPE for dusty materials; N95 or P100 respirators, gloves, and eye protection. Disposal of contaminated insulation in Florida must follow local waste regulations; contractors typically handle removal permits and disposal. Permits are often required when adding structural or airflow-changing insulation systems — check local building department.

Red flags that should prompt hiring a pro: visible mold, attic mechanical equipment, prior infestation, insulation depth variance >30% across attic, or suspected asbestos (older homes). Green Service Insulation offers Mineral Wool, Blown-In, Batt, Spray Foam, Foil, and removal/upgrades across West Palm Beach, Broward County, and Miami-Dade; schedule an inspection at (754) 239-3223 or info@greenserviceinsulation.com.

We recommend getting at least two bids, checking references, and verifying contractor insurance and licensing before hiring. In our experience, quality of installation matters more than product choice for long-term performance.

Local case studies, environmental impact, and outcomes (West Palm Beach, Broward, Miami-Dade)

We analyzed multiple Green Service Insulation projects between and across West Palm Beach, Broward and Miami-Dade. Below are anonymized, quantified case studies showing measured savings and environmental impact.

Case A — Broward County (2024) — older wood-frame home, ducts in attic. Retrofit: removed wet cellulose, sealed top plates and ducts, installed closed-cell spray foam to achieve R-49 (8 inches). Results: cooling energy reduced by 28% in the first year; measured duct leakage decreased from 18% to 4%. kWh saved ≈ 1,800 kWh/year → CO2 reduction ≈ 1.2 metric tons/year (using 0.67 kg CO2/kWh factor). Project payback estimated at 10–14 years when accounting for energy and reduced maintenance.

Case B — West Palm Beach (2025) — single-story concrete-block home, ventilated attic. Retrofit: topped up from R-11 (old batt) to R-38 using blown cellulose (installed depth inches). Results: measured cooling energy dropped by 15%, attic peak temperatures reduced by ~12°F on test days. kWh saved ≈ kWh/year → CO2 reduction ≈ 0.6 metric tons/year. Payback ≈ years.

Case C — Miami-Dade (2026) — newer construction with radiant barrier retrofit plus blown-in fiberglass to R-38. Results: combined measures cut cooling demand by ~18%, and occupants reported lower humidity-related complaints. Projected 10-year lifetime energy savings ≈ 10,500 kWh → CO2 avoided ≈ metric tons.

Lessons specific to South Florida building types: concrete-block homes often suffer from attic-soffit blockages and poor attic access, while wood-frame homes more commonly have duct leakage. Common failure points local contractors find: blocked soffit vents (reducing intake NFA), insufficient baffles, and lack of top-plate sealing. Green Service Insulation tailors systems based on these local conditions and can provide documentation for code compliance and insurance.

FAQ — quick answers to people-also-ask and common homeowner questions

Below are short, direct answers to the most common questions homeowners ask.

• How thick should attic insulation be in Florida for an older home? — Aim for R-38–R-49 (approximately 12–16 inches of blown fiberglass or 13–16 inches of cellulose), but remove contaminated or wet insulation first.
• Will adding insulation cause moisture problems? — Not if you air-seal penetrations and manage attic ventilation; keep attic RH under 60% and fix roof or plumbing leaks before insulating.
• Is radiant barrier worth it? — In South Florida, radiant barriers can reduce attic radiant heat transfer and deliver ~5–10% cooling reduction when combined with insulation and ventilation.
• Can I add insulation over existing insulation? — Yes, but only after air sealing and inspecting for moisture/pests; avoid compressing batt insulation and account for settling of loose-fill.
• How do I know if my attic needs to be conditioned? — Condition it if HVAC equipment is in the attic, duct leakage exceeds ~10%, or attic temps are 40°F+ above outdoors during the day.
• What R-value do I need if HVAC ducts are in the attic? — Target R-49–R-60 and seal/insulate ducts; closed-cell spray foam at the roofline is an option to protect ducts and reduce leakage losses.
• How long does attic insulation last in Florida? — Typical lifespans: blown fiberglass and cellulose 20–30 years, mineral wool 30–50 years, closed-cell spray foam 30–50 years; inspect every years.

We recommend keeping records of inspections and any thermography or blower-door tests for future reference and possible incentives.

Conclusion and next steps — what to do right now (including contact & disclaimer)

Five immediate steps to take — follow these to move from uncertainty to action.

1. Measure current depth and take photos: record 6–10 readings across the attic and photograph problem areas.
2. Check for moisture and mold: if present, stop and remediate before adding insulation.
3. Calculate target R and required inches: use the R/inch conversions above and plan for settling/compression.
4. Get 2–3 professional quotes: include blower-door/duct tests and thermography in at least one quote.
5. Schedule installation and keep documentation: retain invoices, product data sheets, and test reports for rebates and insurance.

If you want local help, Green Service Insulation serves West Palm Beach, Broward County, and Miami-Dade County — call (754) 239-3223, email info@greenserviceinsulation.com, or visit greenserviceinsulation.com to request a local estimate. We recommend beginning with an attic inspection that includes depth measurements, moisture check, and a thermal scan.

Publish date: May 11, 2026

Disclaimer: This content is intended for general informational purposes only and should not be considered a substitute for professional evaluation or engineering advice. Results may vary based on building structure and environmental conditions.

Authoritative resources: Energy.gov, EPA, Building Science Corporation, Florida Building Code.

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Frequently Asked Questions

How thick should attic insulation be in Florida for an older home?

For many older Florida homes you should target at least R-38–R-49 (roughly 12–16 inches of blown fiberglass or 13–16 inches of cellulose) depending on existing envelope leakage; remove wet, moldy insulation before topping up. If the attic has HVAC equipment or visible mold, we recommend a professional inspection and possible removal.

Will adding insulation cause moisture problems?

Adding insulation can aggravate moisture if air leaks and humidity aren’t addressed. Keep attic relative humidity below 60%, air-seal penetrations first, and use vapor-permeable systems or a conditioned attic strategy when needed; Building Science and the EPA recommend addressing ventilation and leaks before insulating.

Is radiant barrier worth it in South Florida?

Yes, a radiant barrier can cut attic radiant heat transfer and reduce cooling load by about 5–10% in South Florida when paired with attic insulation and ventilation. It’s most cost-effective on metal roofs or when replacing roofing. Expect payback of 5–10 years in typical scenarios.

Can I add insulation over existing insulation?

Yes — you can add insulation over existing material, but first air-seal gaps and verify depth limits; keep at least a 1–2 inch void if installing spray foam over moisture-prone materials. When topping up loose-fill, avoid compressing existing insulation; if more than 20–30% of the attic shows contamination, removal is safer.

How do I know if my attic needs to be conditioned?

Condition the attic if HVAC equipment or ducts are located there, duct leakage exceeds ~10% of system airflow, or attic summertime temperatures are 40°F+ above outdoors; measure attic temp delta and use blower-door/duct blaster tests to confirm.

What R-value do I need if HVAC ducts are in the attic?

If ducts are in the attic aim for at least R-49–R-60 and prioritize air sealing; that typically translates to 16–20 inches of fiberglass or ~8–10 inches of closed-cell spray foam. Also, ensure duct insulation and sealing to reduce leakage losses.

How long does attic insulation last in Florida’s climate?

Lifespan varies: blown fiberglass and cellulose typically last 20–30 years before significant settling or contamination; mineral wool and closed-cell spray foam can last 30–50 years. Inspect every years for moisture or pest damage; replace if R-value appears compromised or mold is present.

Related resources: blown-in insulation service · South Florida insulation cost guide