Top-Rated Insulation Installers in Islip, NY
5 local companies ranked by 732 Google reviews. Free to compare, no sign-up.
Short answer: The top-rated insulation installers in Islip are Zavza Seal LLC (4.9★, 120 reviews), Rocket Insulation (5.0★, 19 reviews), Infinity Attic (4.7★, 58 reviews).
Insulation installers in Islip, ranked
- 4.9 (120 Google reviews)80 Orville Dr Ste 100, Bohemia, NY 11716
- 5.0 (19 Google reviews)40 Haynes Ct, Ronkonkoma, NY 11779
- 4.7 (58 Google reviews)470 Suffolk Ave, Brentwood, NY 11717
- Green Team LIMost reviews4.6 (406 Google reviews)332B Dante Ct, Holbrook, NY 11741
- 4.6 (129 Google reviews)1593 D, Locust Ave, Bohemia, NY 11716
Together these 5 companies average 4.7★ across 732 reviews. Green Team LI has the most reviews (406).
Ranked by Google rating weighted by review count, collected September 2026. Rankings are not paid for. How we rank and how we make money.
Listed here? Get your top-rated badge for your website or print the Islip rebate sheet for your customers.
What a insulation costs in Islip
Price depends on which areas you insulate (attic, walls, basement) and how much air sealing is needed. Ask each company for a price per area and the R-value you end up with, so quotes are easy to compare.
Financing or future programs may still help. Check the rebate page before you sign.
Rebates: our verified program data, checked monthly. Always confirm the exact amount for your home.
Talk to a home energy auditor first. Some utility programs want an audit before any work starts. See the top-rated home energy auditors in Islip.
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Why insulation matters in Islip
In Islip, the average January low is -2°C (29°F), colder than 31% of the 123 cities we track. Winters here are mild, so comfort and summer heat matter as much as heating bills. Air sealing and attic insulation still help most, and they also keep upstairs rooms cooler in summer.
Most rebate programs pay only after an energy assessment, and some need one before the work too. Book it first.
Source: Open-Meteo historical weather data, 2015-2024.
Before you hire an insulation installer
- Ask whether they will air-seal before insulating, and what they will seal (attic hatch, pot lights, pipes, top plates).
- Ask for the R-value before and after for each area, and the material and depth they will install.
- Ask whether your rebate needs an energy assessment before and after the work, and who books it.
- Ask how they handle ventilation and any old insulation that could contain vermiculite (asbestos risk).
Questions about insulation installers in Islip
Who is the best insulation installer in Islip?
Based on Google reviews, the top-rated insulation installers in Islip are Zavza Seal LLC (4.9★, 120 reviews), Rocket Insulation (5.0★, 19 reviews), Infinity Attic (4.7★, 58 reviews). We rank by a review-weighted score, so companies with many strong reviews rank above those with only a few.
How are the insulation installers in Islip ranked?
We list 5 insulation companies in Islip, ranked by Google rating weighted by review count. Together they have 732 Google reviews and average 4.7 stars, collected September 2026. Green Team LI has the most reviews (406). No company pays to be listed or ranked.
How much does insulation cost in Islip?
Insulation prices depend on which areas you insulate (attic, walls, basement) and how much air sealing is needed. Ask each company for a price per area and the R-value you end up with, so quotes are easy to compare.
Are there rebates for insulation in Islip?
We have no confirmed open insulation rebate for Islip right now. Financing or future programs may still help, so check the rebate page before you sign.
Is insulation worth it in Islip?
In Islip, the average January low is -2°C (29°F), colder than 31% of the 123 cities we track. Winters here are mild, so comfort and summer heat matter as much as heating bills. Air sealing and attic insulation still help most, and they also keep upstairs rooms cooler in summer. Most rebate programs pay only after an energy assessment, and some need one before the work too. Book it first.
What should I ask an insulation installer before I hire?
Ask whether they will air-seal before insulating, and what they will seal (attic hatch, pot lights, pipes, top plates). Ask for the R-value before and after for each area, and the material and depth they will install. Ask whether your rebate needs an energy assessment before and after the work, and who books it.
Before you call anyone, check what insulation rebates you can get in Islip. Many programs require approval or a registered contractor before work starts.
Planning more upgrades? See the top-rated heat pump installers, solar installers, home battery installers, home energy auditors in Islip.
How to read these results
- Open the profile.How a installer describes its own work tells you a lot. Look for jobs like yours.
- Read the Google reviews.Stars and counts come from Google Maps. Click through and read what past customers wrote, good and bad.
- Check for program badges.A green registered-contractor badge means the company is on the program's own list, which some rebates require.
- Compare three.Do not stop at the first good installer. Three quotes show you the real range in price, equipment and plan.
Not ready to talk to a contractor yet?
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