Sheathing Interior Garage Walls With Plywood (Updated)

By Todd Fratzel on Garages, Insulation

sheathing+interior+of+garage Sheathing Interior Garage Walls With Plywood (Updated)Sheathing the interior garage walls with plywood is a great alternative to drywall. Let’s face it, garages take some abuse and when I see drywall inside the garage I just cringe. Drywall doesn’t do well when it get’s wet, it certainly won’t do well when you slam something against it and it’s a real pain when you want to hang things on the wall. That’s why I prefer using plywood on the walls.

When we built the new house the garage was left unfinished on the inside. There were no stairs the the attic, no finished wall coverings and no storage. I’ve been slowly trying to find time to get the garage finished so it doesn’t look like a bomb went off in there. Last fall I built a staircase to the attic (eventual work shop).

Before cold weather sets in I decided to finally insulate the garage walls and sheath them with 1/2 inch SYP under-layment. I chose the under-layment because it has a rather finished smooth side that I thought would look nice in the garage. Obviously using plywood isn’t as cheap as drywall but it comes with some great benefits.

fiberglass+insulation+garage Sheathing Interior Garage Walls With Plywood (Updated)Using plywood on the walls allows me to screws brackets, hooks, shelves and anything I want to the wall without fear of it pulling out. Plywood is very tough and it won’t be getting damaged every time something or someone slams into it. The other nice feature of using plywood is it’s easy to work with. I’m not sure about you but I’d rather hang plywood anyday compared to drywall!

Before I put the plywood on the walls I insulated the garage walls with unfaced R19 fiberglass insulation. I prefer using unfaced insulation and then installing a layer of plastic as the vapor barrier.

The key to a good fiberglass insulation installation fiberglass+R19+unfaced+insulation Sheathing Interior Garage Walls With Plywood (Updated)is making sure the insulation has plenty of loft and it’s not compressed into the stud bay. As you can see in the photo the insulation is nice and “fluffy”. I made sure not to compress the insulation especially along the studs.

It’s important to wear a mask when you work with fiberglass insulation to keep the fiberglass out of your lungs. I also recommend wearing a long sleeve shirt to prevent excessive itching. All you need for tools when working with fiberglass insulation is a utility knife, tape measure and something to cut on.

I still haven’t decided what to do with the ceiling of the garage as far as insulation and sheathing. My problem is decided how to integrate that work with the actual workshop in the attic space. Stay tuned for future posts where I’ll tackle that project.

Garage+firewall Sheathing Interior Garage Walls With Plywood (Updated)Update:
After getting some comments and feedback I thought it was important to note something about firewall separations. Most building codes require a one hour minimum fire separation between living space and garages. As you can see in the adjacent photo the gable common wall between our garage and the house has been covered with one layer of 5/8 inch thick fire rated drywall. It’s also worth noting that most plywood is fairly safe in a garage because it has a flame spread rating of at least category C which basically means it won’t just catch on fire from an open flame. Just make sure you check your local codes before installing plywood on the garage walls.

About the author

Todd Fratzel

I'm full time builder for a large construction company in New Hampshire. I run their design-build division that specializes in custom homes, commercial design-build projects and sub-divisions. I'm also a licensed civil and structural engineer with extensive experience in civil and structural design and home construction. My hope is that I can share my experience in the home construction, home improvement and home renovation profession with other builders and home owners. I'm also the author of Tool Box Buzz and Today's Green Construction. Please feel free to contact me if you have any questions, suggestions or you'd like to inquire about advertising on this site.

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8 Comments

  1. Brooklyn Row House says:

    It should probably be noted that people should check their codes. The IRC and UBC require a minimum 3/4-hour fire rating for any garage-facing wall or ceiling adjacent to a residential living space.

    In NYC, it’s even tougher. You need masonry walls and two layers (1-1/4″) of Type X on the ceiling if there’s a living space above. That’s actually a relaxing of the NYC Residential Code, which used to require laminated tin sheathing on the ceiling.

  2. Todd says:

    Good reminder. We actually have 5/8″ drywall on the house/garage wall. I should have mentioned that in the post, perhaps I’ll post a picture of the fire wall for reference. Thanks for the reminder!

  3. Scott Becker says:

    I like the plywood idea for all the reasons that you mentioned, but also am concerned about the code. What about fire rated dry wall for the ceiling? Could combine 2 good ideas.

  4. Todd says:

    The only place the fire rating is needed is the junction between the two structures. I’ll post pictures of mine so you can see. The 5/8″ fire rated drywall goes all the way up the joining gable wall.

  5. Perry Degener says:

    The plywood sounds like a tough surface, but how do paint it to achieve a smooth surface; does it need spread Bondo?

  6. Todd says:

    I’m not planning on painting it, I’ll leave it natural.

  7. Guy says:

    Recently on a kitchen remodeling we built a new interior 2X4 wall around the outside wall in order to make it easier to install all the new plumbing, receptacles, light switches, phone and TV outlets. We had a suggestion to hang a 1/2″ plywood to make the new cabinet installation a lot easier without looking for the studs. Now we are concerned about the fire rating without the drywall. My question is does an exterior wall of a single story 1955 red brick bungalow need a one hour fire rating?

    • Todd says:

      Guy – I can’t tell you for sure as it would depend on your local building code. However, most codes that I’m used to would not require the exterior wall to be fire rated unless it’s a wall adjacent to a garage. In that situation the fire rating needs to be on the garage side. I’ve actually remodeled a kitchen before by installing 1/2″ plywood behind the cabinets and drywall elsewhere.

      Most residential building codes deal with flame spread ratings on wall surfaces. I think your real issue is whether or not it’s a fire wall by code.

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