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What is the best way to insulate my attic?

By FPL Expert

Asked on: December 12, 2012 by Joseph H.; Mims, FL

What is the best way to insulate my attic? Can I install insulation between the rafters?

If your home is more than 30 years old, it may have been built without ceiling insulation. FPL customers who improved their ceiling insulation have seen average savings of $30-$68 per year depending on their previous level of insulation, so you may want to consider the following options for insulating your attic:

Paper backed blankets of fiberglass insulation work well for attics with enough height to work inside. The insulation can be laid between the wooden beams on the attic floor to provide an even level of insulation throughout your home. Choose products with an insulating value of at least R19.

Blown-in insulation works well too. Five inches of blown fiberglass or three inches of cellulose will provide an insulating value of R19. Tell your installer you will be checking to see if they applied an even layer across the entire attic at the end of the job.

Insulating foam can also be sprayed onto the attic ceiling. Spray foam is only recommended for homes with sealed attics and tile, metal, or light color shingle roofs.

Start saving now. Visit www.FPL.com/ceilinginsulation to schedule a home energy survey and have your insulation checked.

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Comments [31]

  1. Drpree

    I was in the Sheet Metal Businesss. Being a Metal worker for 42 years i found tha near the end of my career many of the wealthier people in Palm Beach would Spray the under side of the Roof Sheathing. They would even A/C the attic so the equipment would be in a controlled environment. It sounds like a Great idea but I’ve wondered if the roof gets a leak How can you search it out with all the foam hiding the leak?? Tanks Dupree

  2. Tony Mamone

    How do we extend the life of our tile roof in South FL. We are seeing the homes in our neighborhood replacing clay and concrete tile roofs in 15-20 years. this is primarily due to the breakdown of the felt and sealer underneath the tiles.
    The homes are insulated with R19-38 batts in the ceiling joist.
    We are getting ready to replace our roof, what can be done to extend the life of this roof in the S Floridia sun conditions/
    thank you,
    Tony Mamone

  3. Wilie

    A solar power ventilater can pull the hot air out and bring in a cooler air from the outside.Solar power is free and cooling the attic is like having a neighbor living upstairs cooling that space so you don’t have to fight against the summer HOT days… 😉 willie

  4. Richard

    I am about to Upgrade my 30 yr. home ? R-19, batt attic floor insulation with Blown in R-30 Fiberglass, and roof Spray On Radient Barrier per Contractor recom). Needless to say Pros/Cons Of Each which were never ‘Fully’ Discussed, for I did not know as much then as I do now..sound familier? I did some checking between products, Cellulose appears best overall. Even Pros/Cons Spray Foam Radient Barrier (75% effective) vs Foil (95% effective)
    After 30 yrs workers installing lighting fix’s, cables, Air Cond. Handler (in attic)and whole house plumbing etc ‘clutter’ found more often than not owners may not have any idea of all this, now someone comes along and offers to spray 2’to 3’over it all? Also what about small holes (air leaks) around any fan or light cannisters, elect/cable lines they should be filled over ? Nothing seems to ever be discussed.
    Wish Me Well

  5. Barry

    I just removed some blown-in insulation from between the floor jousts. Should the paper insulation go paper (vapor barrier) up or down for best effectiveness? Florida attic,hot attic well vented. Thanks

  6. Liquid EPDM

    That is a nice discussion out here i like discussion because it solves the greatest problems by just few comment and reviews

  7. st louis home insulation

    If you don’t have any or it has been a while since you installed it, adding to your roof insulation can really help with summer cooling bills. This should be the first step for anyone looking to improve efficiency. Good quality roof insulation can cut the temperature inside your house by several degrees in summer..

    After that, look into blocking light from getting through your windows by tinting them, installing awnings or using solar blinds.

  8. Sharon O'Hara

    We purchased an older double wide mobile home. Can insulation be added to the ceilings in these homes?

  9. Bob

    On the paper backed blankets of insulation the paper should be against the dry wall ceiling in between the wooden beams, with the insulation on top. If you put the paper on top you trap any moisture from the house in the insulation??

  10. jake

    Is it worth it to replace old TVs and PC Monitors
    for new ones.
    How much do you save from an older TV to a new one?
    Thank you

  11. Michael Pettinicchio

    When I bought my home,previously owned, I noticed that the garage ceiling in the attic is not insulated. I am thinking of insulating this myself but don’t know if this is the correct thing to do. Please advise. Thanks, Mr.P

  12. Gary Wamsley

    We have a 2,000 SF ranch in PBG with a vented attic & 3.5 inches of blanket insulation. Will adding 3 more inches of insulation save us much money versus the cost ?


  13. KELLY D


  14. BR Rock

    If using such, reflective panels, which is the best orientation:
    reflective side UP or DOWN?
    Better to force panels flush against the roof boards …?
    … or place them just inside joists/rafters (which would leave an airspace about as thick as the joists/rafters).

    Dania Beach, FL

  15. BR Rock

    What about the best way to utilize instead the stiff, fiberglass panels for insulation (like the 1-inch thick material used to construct 4-sided air ducts which are used to channel air from the a/c or heating units)?
    [This we already have … you know, the kind with one, outer wall made of reflective aluminum, right.]
    We want to know how it would compare, especially if friction fit into the UPPER rafters (joists?), upon which the roof boards are secured, etc.
    Your other methods do reduce the heat transfer into the living spaces below, but why not insulate against the INSIDE of the roof somehow, and thus reduce the heat transfer into the attic space itself in the first place?
    (Many added benefits, including eliminating heat stress for items that may be stored in the attic, etc.)

    Dania Beach, FL

  16. john sinkinson

    I have 3.5″ in my attic and wonder what potential AC savings can be had by adding more insulation. Understand the big savings is in heat loss, but in Cape Coral my big FPL cost driver is the AC as I very rarely have to use heat.

    please n thanx

  17. Harry Sterling

    I was always told to install pink fiberglass insulation with paper down in the attic. Toward the drywall. When your in the attic you see pink insulation. Paper on room ceiling side. Please verify for me. Thanks Harry

  18. Sandy Stubbs

    I just had Truly Nolan blow in the the R-19 to a depth of 5 inches.Can I get a rebate for saving engery.

  19. Lester Jensen

    While remodeling home with the ceiling removed installed NEW insulation between the beems from below and stapled the paper back instulation to the bottom of the beams and then had the contractor install the ceiling dry wall ….. did I reduce the effectiveness of the insulation by doing that and was that even the correct way of installation…and if not what would I do now to increase the effectiveness of the insulation there

  20. Joseph Abreu

    Although my attic is very high (you can stand in my attic)it is filled with clutter. Does this prevent air circulation and increase heat?

  21. genealbelo

    Is there some way of insulating patio doors; seems that much of the energy lost is through patio doors.

  22. sergio granados

    for a flat roof what is the best insulation that can be use? I have some places with insulation but the rest i have no idea. thank in advance.

  23. Joseph Goodof

    Air conditioneing units in Florida might do a much better job of cooling a typical 2 Br,2 Bath home if the ductwork was run along the inside of the house instead of the attic which reaches 115 degree or higher during the several summer months.Before the sun rises on a summer morning in August, I can measure 65 degrees coming out of the ceiling vent…by 2 PM when it’s 92 degrees or higher after the noon hour, the A/C needs to run continually to barely keep the inside house temerature at 82 degrees. Tell me that I am mistaken in thinking that the hot attic does impact on the air inside the ductwork…which, by the way has been inspected by an FPL agent. I have from 5 to 12 inches of blown in insulation..it doesn’t cover evenly through the attic but is about 80% coverage very well. The A/c is new, two years ago.. asiode the 2or 3 months of hot summer weather, it does very well and my FPL bill “is a delight” to receive…during”off season, the bill is barely 50 dollars a month with a household full of electric appliances… the Air Conditioning months will cost me about 50 dollars more per month, included with the discount we have with FPL on the control box that intermittently closes off power to the washer and A/c.. and that happens seldom. We’re appreciative for FPL service.

    1. Wilie

      They have different types of Ducting. We use to install Sheet Metal Pipes that we would wrap with paperback and then later Foil back insulation. It was 1″ thick. It would have to be sealed to keep moister out. Then they came up with Fiberglass duct board. it was 1″ thick too. Now they have 1/12′ or 2″ thick duct board that is required it the attic. under a 2 story house the first level home could use 1″. Any time you can put the Unit or Ducting in a “Conditioned area” the unit doesn’t have to work as hard. If all this gets too confusing get a home in the South and a home up North Problem solved. “Snowbrids” 😉 willie

    2. Peggy Hoxie

      My garage seems extremely hot during the summer months and that is where my washer and dryer are located. How much can I save on my electric bill by putting insulation on my garage door?

  24. John

    When you say to use paper backed fiberglass insulation between the floor beams (joists), I assume the paper is the vapor barrier. If that’s the case then the vapor barrier should not face ‘up’ but down towards the living space.

  25. RJ Arena


    Concerning your comment about attic placement of paper backed fiberglass insulation — shouldn’t it be installed paper side DOWN, i.e paper against the sheetrock of the ceiling below to take full advantage of its moisture infiltration resistance properties?


    RJ Arena

  26. Bill Spooner

    Any suggestions on insulating garage doors?

  27. John

    I have a radiant barrier and R-19 rolled insulation. Is this combination better than just the insulation?

  28. Cathy Rideout

    can you tell us about the benefits of radiant insulating? thanks

  29. Mike LeBelle

    Is the installation of paper-backed insulation recommended with the paper up? Up north, this used to go on the warm side (interior) to help form a vapor barrier although better systems are in place now. Does paper-up insulation not encourage moisture build-up in the insulation and potential mold growth.


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