How Much Is 1,000 Sq Ft of Insulation?

Let’s be honest—most folks treat their garage like a junk drawer with a garage door. It stores tools, bikes, holiday decorations, maybe a fridge with exactly one beer in it. What it usually doesn’t have? Proper insulation. And that’s a problem.

‍

If your garage is uninsulated, it’s probably one of the biggest energy leaks in your home. Heat escapes in winter, swelter creeps in during summer, and if there’s a room above it, you’re basically trying to heat a bedroom that sits on a giant ice cube. Not ideal.

‍

The good news? Insulating your garage isn’t rocket science—but picking the right insulation material matters. Spray foam, fiberglass, cellulose, rigid board—each has pros, cons, and a sweet spot depending on whether your garage is heated, finished, detached, or just plain drafty.

‍

In this post, we’ll break it all down so you can stop wasting energy and start treating your garage like part of your house (instead of a glorified shed). Let’s get into it.

Key Factors to Consider When Choosing Garage Insulation

Before we start ranking insulation like it’s a fantasy football draft, let’s cover the basics. The best insulation for your garage isn’t just about R-value—it’s about how your garage is built and what you actually use it for.

‍

Here’s what you need to think about:

Heated vs. Unheated Garage

If your garage has a space heater, ductwork, or you’re trying to make it livable year-round (hello, home gym or workshop), you’ll want high R-value insulation with solid air sealing—think spray foam or dense-pack cellulose.
‍

If it’s unheated and more of a storage space, you can get away with a simpler setup like fiberglass batts or rigid foam panels—just enough to take the edge off.

‍

Attached vs. Detached

Attached garages matter a lot more for home comfort. Every cold draft or heat wave in the garage eventually makes its way inside.
‍

Detached garages? Still worth insulating, especially if you’re working out there or storing anything sensitive, but you’ve got a little more leeway.

‍

Climate Zone (Hint: Connecticut = Cold)

Around here, we deal with real winters—ice on the windshield, pipes that groan, the whole deal. That means higher R-values and moisture resistance are non-negotiable. Closed-cell spray foam or thick cellulose makes a big difference.

‍

DIY vs. Pro Installation

Some materials—like fiberglass batts or foam board—are DIY-friendly if you’re handy and have the time.
‍

Others—like spray foam or dense-pack cellulose—really shine when installed by a pro who knows how to air seal properly (and doesn’t mind getting covered in dust or foam in the process).

‍

Moisture, Mold & Pests

Garages see more humidity swings, water drips, and pest visitors than other parts of the house. Choose an insulation material that won’t soak up moisture or turn into a mouse hotel. (Looking at you, cheap fiberglass.)

Top Garage Insulation Materials (Ranked by Performance and Budget)

Alright, now that you know what you’re working with, let’s break down the best garage insulation materials—what they cost, how well they work, and when to use each one.

‍

This isn’t about what sounds good on a label. It’s about what actually works in real-world garages, especially if you’re here in New England where winter hits like a freight train and summer turns your garage into a sauna.

1. Blown-In Cellulose

Best for: retrofitting garage walls or ceilings with existing cavities
R-Value: ~R-3.5 to R-4 per inch

Cellulose is made from recycled paper, treated for fire and pest resistance, and it’s fantastic at filling awkward spaces—especially in older garages with gaps and funky framing. Dense-pack versions also block air flow surprisingly well.

Pros:

• Eco-friendly and cost-effective
• Great sound dampening
• Fills cavities better than batts

Cons:

• Can settle over time if not installed properly
• Needs proper air sealing to avoid moisture issues
• Blower equipment required

💡 A solid choice for budget-conscious homeowners who want performance.

‍

2. Spray Foam Insulation

Best for: maximum air sealing, extreme temperatures, humid or drafty garages
R-Value: ~R-6.5 per inch (closed-cell)

Spray foam is the heavyweight champ of garage insulation. Closed-cell foam doesn’t just insulate—it seals air leaks, blocks moisture, and adds structural rigidity. If your garage is heated or attached to living space, this stuff earns its keep.

Pros:

• Highest R-value per inch
• Excellent air and moisture barrier
• Great for rim joists, ceilings, and walls

Cons:

• Most expensive option
• Professional installation required
• Overkill for detached garages you rarely use

💡 Use it if you want your garage to feel like part of your home—not a separate weather system.

‍

3. Fiberglass Batts

Best for: quick DIY jobs, basic wall cavities
R-Value: ~R-3.2 to R-3.8 per inch

Old-school and still widely used. Fiberglass batts are available at every big-box store and can work fine—if installed correctly (and that’s a big if). They don’t seal air gaps, so pairing with caulking or foam is a must.

Pros:

• Low cost and widely available
• DIY-friendly
• Quick install

Cons:

• Poor air sealing on its own
• Loses effectiveness if compressed
• Attracts rodents if left exposed

💡 Not ideal for damp or unconditioned garages, but not bad if you’re in a pinch.

‍

4. Rigid Foam Board

Best for: garage doors, concrete walls, ceiling panels
R-Value: ~R-4 to R-6.5 per inch

Rigid foam boards are a moisture-resistant solution that works great in garages with masonry or metal surfaces. They can be glued or screwed to walls and ceilings, or cut to fit into garage doors.

Pros:

• Excellent moisture resistance
• Easy to cut and install
• Great for unvented or humid garages

Cons:

• Requires sealing at joints
• Needs a thermal barrier (like drywall) in living-adjacent areas
• Brittle if not handled carefully

💡 A smart solution for insulating garage doors or foundation walls where you can’t use batts or spray foam.

‍

5. Garage Door Insulation Kits

Best for: quick comfort upgrades
R-Value: ~R-4 to R-8 (varies by kit type)

These kits use reflective bubble wrap or foam panels that attach to the inside of your garage door. They won’t turn your garage into a sauna, but they’ll knock down the summer heat and reduce winter drafts.

Pros:

• Affordable and fast
• DIY install in an afternoon
• Helps reduce radiant heat gain

Cons:

• Limited R-value
• Doesn’t seal air leaks
• Mostly cosmetic if done poorly

💡 Great for a weekend project—just don’t expect miracles.

‍

Which Garage Insulation Material Is Right for You?

There’s no one-size-fits-all answer here. The right insulation depends on how your garage is built, what you use it for, and what kind of headaches you’re trying to avoid.

‍

Here’s a cheat sheet:

• Attached & unheated: Foam board or fiberglass batts
• Attached & heated or room above: Spray foam or dense-pack cellulose
• Detached workshop: Blown-in cellulose or fiberglass batts
• Moisture or pests: Closed-cell spray foam or rigid board
• Soundproofing or gym: Dense-pack cellulose or spray foam are great for soundproofing

Don’t just pick the cheapest material—pick the one that fits your garage.

DIY vs. Pro Garage Insulation: What’s Worth Tackling Yourself?

Some insulation jobs are dead simple. Others? They’ll have you wishing you’d just called someone with knee pads and a compressor.

Good DIY Options

• Fiberglass batts
• Rigid foam board
• Garage door kits

‍

Great for open walls, tight budgets, and folks who aren’t afraid of a utility knife.

Call a Pro When:

• You want spray foam or dense-pack cellulose
• Your garage is finished or has hidden cavities
• You’ve got moisture, pests, or weird framing

A good installer brings proper tools, airtight sealing, and a job done in hours—not weekends.

‍

Garage Insulation FAQs

What R-value do I need for garage insulation?

Garage insulation R-values depend on usage. For unheated garages, use R-13 to R-21 in walls. Heated or finished garages need R-19 to R-21 in walls, R-30 to R-38 in ceilings, and R-6 to R-10 on doors. Air sealing is essential to prevent heat loss through gaps.

‍

Will insulating my garage lower energy bills?

Insulating your garage lowers energy bills by reducing heat transfer and easing the load on your HVAC system. Attached garages or those with rooms above benefit most. Insulation in the walls, ceiling, and shared door helps stabilize indoor temperatures and prevent energy waste.

‍

Can I insulate my garage ceiling?

You can and should insulate your garage ceiling, especially if there’s a living space above. Ceiling insulation blocks heat loss, reduces cold floors, improves soundproofing, and boosts comfort. Spray foam or dense-pack cellulose is most effective, but fiberglass batts work with proper air sealing.

‍

What’s the cheapest way to insulate a garage?

The cheapest way to insulate a garage is by using fiberglass batts in the walls and rigid foam board or a garage door insulation kit for the door. This DIY-friendly setup targets major heat loss areas. Avoid gaps and compression to maintain insulation performance.

‍

Can I use the same insulation for my attic and garage?

You can use some of the same insulation for attics and garages, like fiberglass batts or blown-in cellulose, but garages face more moisture, pests, and temperature swings. Closed-cell spray foam or rigid foam board often works better in garages due to their durability and moisture resistance.

‍

Final Thoughts: Don’t Skip the Garage

Most people don’t think of their garage as part of the house… until their bedroom floor feels like a freezer tray or their utility bill spikes every January. The truth is, your garage might be the single biggest weak spot in your home’s thermal armor.

‍

Insulating it the right way—not just with whatever’s on sale—is one of the smartest upgrades you can make. Whether it’s foam board on the doors, batts in the walls, or full spray foam on the ceiling, your garage deserves better than drafty drywall and false promises.

‍
‍

We finally did it—we launched a podcast. Why? Because sometimes you want to learn about insulation without reading a 2,000-word blog post on your phone in the middle of a Home Depot aisle.

‍

And let’s be honest, hearing someone talk through this stuff makes it all a little less confusing (and a lot less boring).

‍

The first few episodes tackle one of the biggest problem areas in any Connecticut home: the attic. We're covering everything from removing old insulation to figuring out which material actually holds up in a drafty, low-clearance crawlspace. We’ll walk through R-values, moisture resistance, rebates, and yes—why air sealing is always step one.

‍

If you’ve ever asked, “Do I really need to rip out the old stuff first?” or “Is spray foam worth the price tag?”—this is for you. Short, sharp, and no fluff.

‍

Heard something that made you wonder what shape your attic’s in? Or maybe you’re just ready to find out what insulation would actually cost for your place?

‍

Let’s be honest—crawl spaces aren’t sexy. They’re dark, musty, cramped, and usually ignored until something starts smelling weird or your floor feels like an ice rink in January. But here’s the truth: that forgotten space under your feet is one of the biggest energy leaks in your house.

‍

The right insulation down there doesn’t just lower your heating bill. It helps control moisture, keeps pests out, and evens out the temperature across your home. And if you're tired of cold floors or a damp basement smell creeping into your living space, it's probably time to take a hard look at what (if anything) is insulating your crawl space.

‍

So—what’s the best crawl space insulation material? That depends on how your home is built, whether the crawl space is vented or sealed, and how much moisture you’re dealing with. In this guide, we’ll break down the top insulation types, compare pros and cons, and help you figure out what actually works (and what just looks good on paper).

‍

Because when it comes to crawl spaces, guessing wrong can mean soggy insulation, mold, or a crew of mice turning your fiberglass into a condo.

Quick Comparison: Crawl Space Insulation Materials

Before we dig into the nitty gritty, here’s a no-fluff breakdown of the most common crawl space insulation materials. Some are built for performance, others for budget—but only a few actually hold up when moisture, cold air, and time start pushing back.

*Foil-faced products don’t have an R-value unless paired with air gaps—they’re more of a thermal mirror than an actual insulator.

Closed-Cell Spray Foam: The All-Around Winner for Most Homes

If you’ve got moisture, air leaks, or wild temperature swings in your crawl space—and let’s be real, most homes around here do—closed-cell spray foam is your MVP. It’s dense, water-resistant, and sticks to just about anything, creating a sealed barrier that keeps outside air and moisture out and your conditioned air in.

‍

Why It Works:

• High R-value: Around R-6.5 to R-7 per inch
• Built-in air sealing that fills every crack and gap
• Moisture resistance that holds up even in damp conditions
• Pest deterrent: mice don’t love it, and neither do bugs

‍

Things to Consider:

• Requires pro installation (this isn’t a weekend DIY job)
• Higher upfront cost, but long-term savings in comfort and energy bills

‍

Bottom line? If you're looking for the best crawl space insulation material for long-term comfort, durability, and moisture control—this is it. Spray foam isn’t just insulation. It’s armor for your crawl space.

Rigid Foam Board: Best for DIY and Budget Projects

If closed-cell spray foam is the Cadillac of crawl space insulation, rigid foam board is the reliable pickup truck. It might not have all the bells and whistles, but it’ll get the job done—especially if you're insulating a relatively dry, unvented crawl space and want to keep costs under control.

‍

Why It Works:

• Good R-value (R-4 to R-6 depending on type)
• Moisture resistant if seams are sealed properly
• Easy to install with basic tools
• Pairs well with encapsulation systems

‍

Things to Watch Out For:

• Needs careful air sealing—gaps defeat the purpose
• Doesn’t perform as well in rim joists or irregular surfaces

‍

So if you’re handy, on a budget, or just trying to avoid fiberglass, rigid foam board can be a smart move—just don’t cut corners on the sealing.

Fiberglass Batts: Popular, Cheap, and Usually a Bad Idea

Fiberglass batts are like fast food insulation—easy to find, cheap to install, and fine in a pinch. But for crawl spaces? They’re usually the wrong tool for the job.

‍

Where It Falls Short:

• Soaks up moisture, which kills its insulating value
• Doesn’t seal air—so even a perfect install still leaks
• Rodents love it. Seriously, they move in and start families

‍

When It Might Be Okay:

• Vented crawl spaces in dry climates (Connecticut doesn’t count)
• Temporary fixes or flips where long-term performance isn’t a priority

‍

If someone’s quoting you fiberglass batts for a damp or unsealed crawl space—run. You’ll be replacing it sooner than you think.

Moisture Is the Dealbreaker (Not Just R-Value)

You can install the highest R-value insulation on Earth, but if your crawl space is damp, it’s not going to matter. Moisture wrecks everything—it flattens fiberglass, delaminates foam board, and turns your crawl space into a science experiment.

Here’s what moisture does to insulation:

• Soaks batts and kills their effectiveness
• Sneaks behind foam board and breeds hidden mold
• Reduces spray foam performance if applied to damp surfaces
• Condenses when materials are installed on the wrong surface

The Fix? Start with Air Sealing and Vapor Barriers:

• Air seal rim joists and gaps
• Lay a vapor barrier on the ground
• Add drainage or dehumidification if needed

Encapsulation—sealing the crawl space and treating it like part of the conditioned home—is often the best solution. It gives your insulation a fighting chance.

What’s Best for Your Crawl Space? (Use Case Breakdown)

Every crawl space is different, so the "best" insulation depends on your setup. Here’s how to figure it out:

‍

Vented vs Unvented Crawl Spaces

• Vented: Avoid fiberglass. Consider rigid foam board or sealing it entirely.
• Unvented: Spray foam is ideal for sealing and insulating in one go.

‍

Cold Climates (Like Connecticut)

• High R-values and vapor-resistant materials are key
• Spray foam and rigid foam board perform best

‍

DIY vs Pro Install

• DIY: Rigid foam board (if you’re thorough with sealing)
• Pro: Spray foam for long-term performance and peace of mind

‍

Budget vs Long-Term Value

• Rigid foam: affordable and effective if installed right
• Spray foam: higher upfront cost, lower bills long term

Cost Breakdown: What to Expect

Let’s talk numbers. Crawl space insulation isn’t glamorous, but it pays off over time.

Typical Total Cost Ranges:

• Basic (vented crawl, budget materials): $1,500–$3,000
• Sealed crawl with spray foam + vapor barrier: $4,000–$8,000+
• Add drainage or dehumidifiers: +$1,000–$2,000

Energy Savings: Expect 10–20% reductions on heating and cooling bills with proper insulation and air sealing.

‍

Rebates: Programs like EnergizeCT often offer rebates on air sealing, spray foam, and crawl space encapsulation. Worth checking out.

Common FAQ's about Crawl Space Insulation Materials

Will insulating my crawl space help with humidity upstairs?

Insulating your crawl space helps reduce humidity upstairs by preventing moisture from rising into living areas. In older homes with unsealed crawl spaces, damp air often moves upward. Sealing and insulating the crawl space creates a moisture barrier that stabilizes indoor air quality.

‍

Is there a benefit to insulating the crawl space floor itself?

Insulating the crawl space floor rarely offers benefits because most energy loss and moisture issues come from the walls and rim joists. Focus on insulating the crawl space walls and sealing the floor with a vapor barrier. Floor insulation is only useful in conditioned crawl spaces.

‍

Can insulation help reduce smells coming from my crawl space?

Insulation helps reduce crawl space smells indirectly by supporting air sealing and moisture control. While insulation doesn't remove odors, spray foam and vapor barriers limit humid air and organic decay from entering living areas, reducing musty or moldy smells.

‍

Do I need to remove old insulation before adding new crawl space insulation?

You often need to remove old crawl space insulation if it's wet, moldy, compressed, or contaminated. Installing new insulation over damaged material traps moisture and reduces performance. A clean, dry surface ensures proper adhesion and long-term effectiveness.

‍

Can crawl space insulation help with noise reduction?

Crawl space insulation helps reduce noise by using dense materials like spray foam and mineral wool to muffle sound from plumbing, HVAC, and traffic. While not a full soundproofing solution, insulation significantly quiets older homes with little or no subfloor insulation.

‍

Conclusion: Don’t Guess—Insulate It Right the First Time

Crawl space insulation isn’t the kind of thing you see every day—but you definitely feel it when it’s done wrong. Cold floors, musty smells, high energy bills... all signs that something down there isn’t pulling its weight.

‍

If you take one thing from this guide, it’s this: the best crawl space insulation material is the one that fits your space, your moisture conditions, and your long-term goals. Spray foam might be king, but it’s not the only option—and rigid foam can hold its own when installed right.

‍

Whether you're looking to DIY it on a budget or hire a pro to seal it up for good, the key is not just picking the right material—it’s installing it in a way that actually works.

‍