Spray foam insulation in Mount Juliet, TN: get up to 3 quotes from vetted local installers
Request free quotes from up to three vetted spray foam installers serving Mount Juliet and nearby Wilson County. Below: what your climate zone means for open vs closed cell, how much insulation to ask for, Tennessee's energy code, and the rebates we could verify.
- Climate zone: 4A (2021 IECC)
- Attic target: R-60 (ENERGY STAR, uninsulated attic)
- State code: 2018 IECC with Tennessee amendments (several 2009 IECC sections substituted)
- Utility rebates we verified: TVA EnergyRight
- Federal 25C credit: ended for 2026 installs
Facts last checked October 16, 2026. Sources are linked in each section.
Where we match quotes from this page
Requests from Mount Juliet and ZIP codes whose center is within about 20 miles of it go to our Mount Juliet, TN partner installers (8 ZIP codes): 37031, 37066, 37075, 37076, 37087, 37090, 37122, 37138. Outside these? Send the form anyway and we'll tell you if we can't match you.
Climate zone 4A: what it means for spray foam
Mount Juliet's central point is in Wilson County, which the 2021 IECC county map assigns to climate zone 4A (mixed-humid in DOE's Building America terms). Zone 4A is a moist ("A") zone, which drives the vapor and R-value rules below.
Other counties within our Mount Juliet service radius: Davidson County (3A), Rutherford County (3A), Smith County (4A), Sumner County (4A), Trousdale County (4A). Not all are the same zone, so check your own county if you live outside Mount Juliet proper.
Source: PNNL-33270, Guide to Determining Climate Zone by County (IECC 2021).
Open cell vs closed cell in Mount Juliet, TN
Attic roofline: both foams are used. The IRC (R806.5) does not require a vapor-retarder coating on open-cell foam under the roof deck in zone 4A (that requirement starts in zone 5), but for hybrid assemblies the foam layer at the deck must be at least R-15 to control condensation. Ask the installer how they manage winter moisture at the roof sheathing.
Closed cell is the usual choice for rim joists, basement and crawlspace walls, where its vapor resistance (about 1.5–2" makes it a Class II vapor retarder) matters most.
How much insulation to ask for
| Where | ENERGY STAR recommendation for zone 4A |
|---|---|
| Attic, uninsulated | R-60 |
| Attic with 3–4" of existing insulation | add R-49 |
| Floor over unconditioned crawlspace/basement | R-19 |
| Basement or crawlspace walls | R-10 continuous or R-13 cavity |
| Exterior walls (when re-siding) | add R-5 to R-10 insulative wall sheathing beneath new siding |
To reach R-60 with foam alone you'd need roughly 16.2–17.1" of open cell (about R-3.5 to R-3.7 per inch) or 8.6–12.0" of closed cell (about R-5 to R-7 per inch). Many roofline spray foam jobs are installed thinner than that and justified through the code's performance path or the unvented-attic rules, so ask every installer to write the foam type, thickness and resulting R-value on the quote and explain how it meets your local code.
Source: ENERGY STAR, Recommended Home Insulation R-Values (based on 2021 IECC). ENERGY STAR's figures are recommendations for existing homes; your local code sets the legal minimum for new work.
Tennessee energy code
2018 IECC with Tennessee amendments (several 2009 IECC sections substituted), effective July 16, 2020. Tennessee amendments reduce ceiling insulation (R-30 in zone 3, R-38 in zone 4) and make duct testing optional.
Source: NAHB, "Residential Provisions of the IECC: State Adoption Status" (current as of May 2026); official state status at DOE Building Energy Codes Program.
Homes in Mount Juliet, TN
Census figures for Mount Juliet city (ACS 2020–2024 5-year estimates): about 16,952 housing units, a median year built of 2006, 9% built before 1980 and 40% built in 2010 or later. 74% are single-family detached homes and 2% are mobile/manufactured homes. 72% of occupied homes are owner-occupied, with a median owner-reported home value of $460,100.
- About 40% of homes were built in 2010 or later, so a lot of local demand is new construction and newer homes. If you're building, ask the installer to show how the foam R-value meets the energy code your city enforces.
- 57% of homes heat with utility gas. Spray foam makes a house much tighter, which changes how gas furnaces, water heaters and fireplaces draft, so ask whether the installer (or your HVAC contractor) will do combustion safety testing after the job. Some utility rebates require it.
Rebates and incentives for Mount Juliet, TN
Utility programs that may apply, depending on which utility serves your address:
TVA EnergyRight (through participating local power companies)
Rebates of up to $300 each for attic insulation, wall insulation, envelope air sealing, and duct sealing/insulation when a TVA Quality Contractor Network member does the work. Eligibility depends on whether your local power company participates.
Read on the program's own page October 16, 2026. Programs change; confirm before you sign.
Tennessee state Home Energy Rebates
Not yet launched Home Energy Rebate Programs
Electrification/appliance rebates (HEAR): "Funding for the Tennessee IRA Home Energy Rebate Programs is not yet available."
Whole-home efficiency rebates (HOMES/HER): "before Tennessee can launch its programs and make the rebates available, it must receive full approval and an executed agreement with U.S. DOE, and then Tennessee must complete the contracting process with our implementer, the Tennessee Valley Authority"
Max rebate (per official page): There is a maximum rebate of $14,000 per building, with percentage caps varying by income and building type.
Official source: TDEC OEP. Status text compiled via referencesource.org, last checked by them August 31, 2026. Full Tennessee rebate page →
What spray foam costs (national published ranges)
We don't have enough local quotes for Mount Juliet, TN to publish local prices, and we won't make them up. These national ranges are a starting point; your installers' quotes are what count.
| Example job (typical thickness) | Estimated installed range |
|---|---|
| 1,000 sq ft attic roofline, open cell (6") | $3,600–$9,600 |
| 1,000 sq ft attic roofline, closed cell (3") | $3,900–$9,300 |
| 1,500 sq ft walls, open cell (3.5") | $3,150–$8,400 |
| 1,500 sq ft walls, closed cell (2") | $3,900–$9,300 |
| 200 sq ft rim joists, closed cell (2") | $520–$1,240 |
Board feet × Angi's 2026 installed price per board foot. Angi reports a national average spray foam project of $2,888 (typical $1,455–$4,337). Check a quote you already have →
Questions to ask each installer
- Foam type, brand, thickness and resulting R-value for each area, in writing.
- Which climate zone and code edition they're designing to.
- Whether removal of old insulation, air sealing, and any required ignition/thermal barrier coating are included.
- Whether they participate in TVA EnergyRight (through participating local power companies), and who files the paperwork.
- Whether they'll do (or coordinate) combustion safety testing if you have gas appliances.
FAQ
What climate zone is Mount Juliet, TN in?
Wilson County is IECC 2021 climate zone 4A, per PNNL's county list (PNNL-33270).
Should I use open-cell or closed-cell spray foam in Mount Juliet, TN?
Both work at the roofline in zone 4A; closed cell is the usual pick for rim joists and basement or crawlspace walls. In hybrid roof assemblies the foam layer must be at least R-15.
How much attic insulation do homes in Mount Juliet, TN need?
ENERGY STAR recommends R-60 for an uninsulated attic in zone 4A (or adding R-49 on top of 3–4 inches of existing insulation). Tennessee's code: 2018 IECC with Tennessee amendments (several 2009 IECC sections substituted).
Are there spray foam or insulation rebates in Mount Juliet, TN in 2026?
The federal 25C tax credit does not apply to insulation installed after December 31, 2025. Utility programs that may apply, depending on which utility serves your address: TVA EnergyRight (through participating local power companies). Tennessee's state Home Energy Rebate program status: Not yet launched.
How much does spray foam cost in Mount Juliet, TN?
We don't publish local prices until we have enough real local quotes. National published ranges are about $0.60–$1.60 per board foot for open cell and $1.30–$3.10 for closed cell, installed (Angi, 2026), and many companies have a $1,000–$2,000 minimum.
How does requesting quotes work?
Fill in the form once. We pass your request to up to three vetted partner installers who serve Mount Juliet, TN, and they contact you to schedule an estimate. It's free and there's no obligation.
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