FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Discussion Forum

Discussion Forum

Separating garage and house

mtpare54 | Posted in Energy, Heating & Insulation on July 21, 2008 11:20am

My semi-new house has a roofline and attic that covers both the garage and a small portion of the house.  This area is largely uninsulated.  I could insulate the whole thing, but is there a better way to divide the temperature controlled house from the garage and only insulate that area?  There is no divider in the attic between the garage and the house, so it all gets cold and hot.

I was thinking of sistering the joist and creating a small wall in the attic space that could then be insulated and then insulate the attic floor, etc.

Ideas?  Thanks for reading.

Reply
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Replies

  1. Piffin | Jul 21, 2008 11:38pm | #1

    Sure, you can build a wall up there, but it is astight and unconfortable a place to work as I imagine, this is a good place for some of that doublebubble foil wrap insulation that is sold under various names ands exaggeratted claims. it is easy to ut to shape and staple into place right up there

     

     

    Welcome to the
    Taunton University of
    Knowledge FHB Campus at Breaktime.
     where ...
    Excellence is its own reward!

    1. Clewless1 | Jul 22, 2008 04:36am | #4

      then add the insulation behind it??

  2. DanH | Jul 21, 2008 11:51pm | #2

    In new construction a firewall would be required between the two areas, at least in most jurisdictions.

    It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May
    1. Clewless1 | Jul 22, 2008 04:37am | #5

      Maybe someone missed this during construction? I agree ... firewall issue here. Maybe the ceiling is a fire rated ceiling providing the separation.

    2. mtpare54 | Jul 22, 2008 04:39am | #6

      Thanks for the advice, so I should put up a full wall in the attic?  There is enough room to stand up, so it would not be that painful.  What would serve as a fire separator?  Studs, insulation, wallboard both sides?

      Thanks again.

      1. DanH | Jul 22, 2008 01:43pm | #8

        Two layers of drywall.
        It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May

        1. Clewless1 | Jul 22, 2008 03:23pm | #9

          Not necessarily ... check w/ the BO. May depend on the jurisdiction. Some 5/8 type X. Some 1/2 type X. 2 layers only if it is NOT type X, I think. The garage ceiling is more likely his fire barrier, I think. Only his BO will know for sure, though.

        2. mtpare54 | Jul 22, 2008 03:31pm | #10

          Great.  Thanks and sorry for the stupid question.

  3. User avater
    BossHog | Jul 21, 2008 11:58pm | #3

    I'm with DanH - It needs a fire separation of some sort.

    Which is harder -- to make education entertaining or entertainment educational?

  4. User avater
    BillHartmann | Jul 22, 2008 04:47am | #7

    "I was thinking of sistering the joist and creating a small wall in the attic space that could then be insulated and then insulate the attic floor, etc."

    Why do you need a wall seperating the parts of the attic to put insualtion on the floor?

    If you are going to use blown in insulation tht will be higher than the joists then you might need to build a small barrier. Just some strips of plywood maybe 12, 18" wide.

    And I can't image a "semi-new" house that does not have insulation on the attic floor unlesss this is "conditioned space". And if it is while you might want to divide off the space you don't want to put insulation on the attic floor.

    .
    .
    A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
    1. mtpare54 | Jul 22, 2008 03:36pm | #11

      Thanks for the post.

      The house was built in 1986, but is new to me.  I should have clarified that.  I could insulate the entire garage, but was thinking it made more sense to separate the conditioned part of the house from the unconditioned garage.  Once the separation was made, I could heavily insulate the conditioned section.  Am I off base?

      1. Clewless1 | Jul 22, 2008 03:42pm | #12

        Is there no ceiling in the garage? Definately insulate only what you need to ... later if you heat the garage ... you can add to it.

      2. JeffinPA | Jul 23, 2008 12:36am | #13

        I'm confused.

        Is the garage attic and the house attic all one big attic? 

        (so either the garage is reall tall or you are in a rancher?)

        If you have flat ceilings in the house, where is the thermal barrier between the house and the attic?

        The floor of the attic should be insulated if built in the 80's!!!

        If the roof of the attic is insulated, then i recon you dont have soffit and ridge vents?!?!

        If there is no insulation, then I would think you would want to insulate the attic floor!

        Are there trusses or rafters?  (I assume rafters since you spoke about ceiling joist)

        Before insulating, if there is none, get some foam and fire caulk and whatever the jurisdication allows under their code, and seal up any holes from the ceiling into the attic (wire holes, along the top plate/ drywall line, around ceiling boxes, especially where chases come up thru (i have seen 2'x2' holes in top of a chase that funnels tons of conditioned air right out of the house)

        This will save a lot of energy costs.  Then I would blow insulation in the attic floor space.  Depending on jurisdiction and codes, you might want anywhere from R-19 to R-42+ as a minimum.

        Regarding fire blocking walls, again depending upon code, you might be alright. 

        If the garage has a drywall ceiling you have some separation.  Every area has something different.  (PA currently allows 1 layer of 1/2" drywall so it is pretty minimal but every area is different and each area changes their code pretty regularly too)

         

        Let me know if I am not thinking this thru correctly and good luck

        1. mtpare54 | Jul 23, 2008 02:59pm | #14

          The garage and part of the house share one big attic.  There is no divider in the attic space between the garage and the house, which to me is a huge waste of energy.  There is soffit and a ridge vent, but I want to place a separator in the attic and get the house section of it insulated.

          Thanks for the help.

          1. john7g | Jul 23, 2008 03:07pm | #15

            You don't need to separate the attic spaces to lay/blow more insul on the attic floor above the living spaces.  Just lay/blow a few feet past the living space. 

            What's the motivation to separate the attic space? 

          2. JeffinPA | Jul 24, 2008 05:44am | #16

            I guess I dont understand where the energy is being wasted. 

            If the whole attic is unconditioned space (soffit and ridge vent, etc) then  it is all outside the thermal envelope and it doesnt matter if the two attics are connected or separated.

            Just insulate the ceiling of the house and seal the ceiling of the house from the attic thoroughly and you have a good energy envelope

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Up Next

Video Shorts

Featured Story

Fire-Resistant Landscaping and Home Design Details

These defensive details give homes a better chances of surviving wildfires.

Featured Video

How to Install Cable Rail Around Wood-Post Corners

Use these tips to keep cables tight and straight for a professional-looking deck-railing job.

Related Stories

  • From Victorian to Mid-Century Modern: How Unico Fits Any Older Home
  • Designing the Perfect Garden Gate
  • Vintage Sash Windows Get an Energy-Efficient Upgrade
  • Design and Build a Pergola

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Fine Homebuilding Magazine

  • Issue 332 - July 2025
    • Custom Built-ins With Job-Site Tools
    • Fight House Fires Through Design
    • Making the Move to Multifamily
  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2024
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data