The Ultimate Guide to Wall Framing & Insulation

Introduction to Wall Framing and Insulation

Wall framing and insulation are two of the most critical components of a high-performance exterior wall. When building an exterior wall without windows or doors, it’s helpful to understand the two major parts:

• Wall Framing: Makes up roughly 25–30% of the total wall area.
• Chamber Insulation: takes up the remaining 70–75% of the wall.

 

Framing supports the structure. The chambers between the studs are filled with insulation. The most common insulation installed in the U.S is fiberglass batts. In colder areas, R-20 batts are more common and in warmer climates, R-13 batts are more common. An R-20 batt fits in a 2×6 framed exterior wall, an R-13 fits in a 2×4 framed exterior wall. A 2×6 is rated at an R-6, a 2×4 is rated at an R-4.

Why is there such a gap in performance between wall framing and insulation? The “R” in R-20 stands for “Resistance to Heat Flow.” Higher R-values mean better resistance, and therefore, greater energy efficiency. An R-20 batt has a much higher resistance to heat flow vs an R-4 2×4 stud. The higher the R-value of the exterior wall the less energy used to heat or cool the building.

Stated VS. Effective Wall Insulation Value

In the past, builders always referred to the stated R-value of the insulation in the wall chamber for the rating for the exterior wall, which was typically R-20 or R-13. The problem is that is not correct, remember the 25-30% wall framing? That is an R-6 for the 2×6 or R-4 for the 2×4. When we do some quick math for a 2×6 wall to average the two values and the effective insulation value is R-13. Ouch! That’s a 35% decrease in insulation value! That loss in insulation value translates directly into higher utility bills. With the cost of electricity, gas, and heating fuels steadily rising, this inefficiency can become a serious burden for homeowners. It’s the difference between a $900 seasonal heating bill for a well-insulated home and $700 in a single month for a poorly insulated 19th-century home. And those older homes are often cold and drafty too!

Saving Money with a Better Insulated Home

Now we are on the next round of higher insulation values for homes. Since the last major change after the Energy Crisis from the 1970’s and subsequent the 1980’s insulation requirements for homes took a big jump. Forty years later it’s time for the next big jump, getting that right is very important. With better framing and insulation, new modern homes can cut seasonal heating costs dramatically or even $0 if it’s a Net Zero Home.

 

Wall Framing Basics

 

What is Wall Framing?

Wall framing is the process of building the structural skeleton of a wall. It includes vertical studs, horizontal plates, and additional support elements such as headers and blocking. Wall framing provides the load-bearing framework that supports drywall, sheathing, windows, doors, and the overall structure of the home.

 

What is Stud Wall Framing?

Stud wall framing refers to the most common method used in residential construction. It involves placing studs such as a 2×4 or 2×6 lumber vertically between a bottom plate and a top plate. These studs are spaced evenly 12,16 or 24 inches on center, to distribute weight evenly and allow for insulation and utilities to be placed between them.

Properly installed wall framing ensures the wall is square, level, and strong enough to meet building codes and energy efficiency standards.

For a deeper dive into framing materials, layouts, and best practices, see our detailed article on How to Construct a Stud Wall.

How to Frame a Wall: Step-by-Step

• How to Layout Wall Framing:
• Here’s a quick snapshot of how to lay out wall framing correctly:
• Lay the top and bottom plates side by side.
• Mark the ends and measure out stud positions (typically 16″ OC).
• Mark locations for corners, intersecting walls, doors, and windows.
• Use a framing square to transfer marks to both plates.
• Assemble your top and bottom plates and marking stud positions.
• Cut and position studs, jacks, and headers as needed.
• Attach studs to the plates using nails or screws.
• Add block, brace, and headers for structural support.
• Secure the bottom plate to the subfloor.

 

Tools & Materials Needed:

• Tape measure
• Framing square
• Level
• Nail gun or hammer
• Circular saw or miter saw
• 2×4 or 2×6 studs

 

To calculate how much materials you’ll need:

• Studs: Divide the total linear feet of wall by 12
• Plates: Divide the wall length by 16 and multiply by 3 (for double top and one bottom plate)
• Adjust for openings: Subtract studs for doors/windows and add jack/trimmer studs
• Add 20% for bracing, blocking, and waste

 

Example: For a 20-foot wall:

20 ÷ 12 = ~21 studs, always add 1 stud
Plates: 20 ÷ 16 = 1.25 x 3 = ~4 boards (round up)

For sheathing, multiply wall height by length to get total square footage, divide by panel area, and add 20% for waste. For interior wall framing, follow the same process but typically with fewer openings and standard studs.

For further framing instructions, refer to our full article on How to Construct a Stud Wall: A Guide to Wall Studs and Exterior Wall Framing.

Wall Insulation 101

Insulation allows the inside of the home to stay at a desired temperature longer and at less cost. The higher the insulation value of the thermal envelope of the home the longer it will stay at that desired temperature without the need of cooling or heating.

A good example is when the power goes out. A super insulated home will keep you comfortable for days with no power. A poorly insulated home you’re looking for a hotel room by day 2.

What Is Wall Insulation Made Of?

Wall insulation can be made from natural or synthetic materials. This is where embodied carbon comes in. Natural or recycled materials typically have a much lower carbon footprint, while synthetic materials, such as rigid foam insulation boards have a very high carbon footprint (i.e. made from oil in a lot of cases). Wall insulations and are designed to trap air within the structure of insulation.

Most insulation materials are soft and designed to fill wall chamber space. Spray foam insulation, such as 2 lb or 3 lb closed cell foam becomes rigid after curing in about 30 minutes. It traps tiny air bubbles in its structure, which makes it an effective vapor barrier at just 1–2 inches thick. Open-cell spray foam functions similarly but is softer, has a lower R-value, and does not qualify as a vapor barrier.

What Does Wall Insulation Do?

Wall insulation helps keep money in your pocket by reducing your utility bills. It makes your home more comfortable, and it’s better for the environment.

Insulation slows the rate of heat transfer, allowing your home to stay at a stable temperature longer and with less energy use. The better your home’s insulation, the less your HVAC system needs to run, saving both energy and costs.

Strength At No Extra Cost

Normally, insulation and framing do not work together. Framing holds the home up; insulation reduces heat transfer. That’s it. If we pulled all the nails out that hold the framing together the entire house would fall apart.

When using the Flash and Fill insulation style with EcoSmart™ Studs that’s not the case, now the framing and insulation work together to not only insulate the house but also to hold the house together. The 2lb closed cell spray foam insulation the (flash part) of Flash and Fill insulation is a 2 part epoxy system. It”glues” and insulates at the same time. The EcoSmart studs are embedded into the 2 lb closed cell spray foam which is also glued to the wall sheathing. Every nail could be pulled out of the EcoSmart Stud wall assembly and the house would remain standing, not fall apart! Extra strength at no extra cost!

How to Install Insulation in Walls

Tools & Safety Gear

The tools and protective gear you’ll need depend on the insulation type. As a general rule, always use safety glasses, a dust mask, and full-body coverage (no exposed skin).

• For DIY wall insulation:
• Utility knife
• Tape measure
• Stapler
• Blower (for blown-in insulation)
• Foam sealant (for sealing chamber holes)

Important: Spray foam insulation (closed or open cell) should always be installed by a licensed professional.

Installation Process

 

1: Check for Vapor Barrier Requirements

Determine whether a plastic vapor barrier, paper-backed insulation, or netting is required in your area. Contact your local city or county inspector to confirm. If a plastic vapor barrier is needed, install it after insulation.

 

2: Seal Gaps and Holes

Seal any holes or gaps where electrical wires, plumbing pipes, or gas lines pass vertically through the wall chamber. Use spray foam sealant. Ignore horizontal penetrations unless they lead outdoors. Do this first so foam has time to cure.

 

Fiberglass Batt Insulation

• Choose the correct width: 16” OC or 24” OC
• Cut batts to length
• Place insulation in chamber
• Cut and split to fit around pipes, wires, or other obstructions
• Staple the paper facing to the studs (if using paper-backed batts)
• For headers: If not spray foamed, gently separate fiberglass to fill the cavity.

 

Blown-In Insulation

• Seal all holes as in Step 2
• Install netting or a smart vapor retarder
• Blow insulation into each cavity using manufacturer’s instructions

Spray Foam, Flash and Fill, CI, ECI, XO Foams

• Spray Foam, Flash & Fill, CI, ECI, XO Foams. These insulation types require professional installation due to chemical handling and application expertise.

 

Insulation Tips: How Much, How Thick & How Long It Lasts

 

How Much Wall Insulation Do I Need?

Check with your local building inspectors for minimum code requirements. Adding more than the minimum is allowed and often recommended, but not the other way around.

 

How Thick Should Wall Insulation Be?

Check with your local code official first for minimum requirements. This depends on climate zone and insulation type:
For example, hempcrete has an R-value of R-2 per inch. To achieve R-24, you’d need 12–14″ thick walls.
Using Flash and Fill insulation with EcoSmart™ Studs, the same R-24 can be achieved with just a 6” wall.

 

How Long Does Wall Insulation Last?

Wall insulation typically lasts for the lifetime of the home or building.

 

Eco-Friendly & High-Performance Options

Building more sustainable and efficient homes starts with smarter materials. Our EcoSmart™ Studs paired with high-performance insulation, are an innovative way to build walls that perform better and cost less to operate.

• Reduced embodied carbon: Fewer materials and smarter design reduce carbon footprint. Read more here.
• Thermal breaks built into the studs reduce heat loss through framing
• Flash and Fill spray foam insulation improves energy efficiency and adds structural strength
• Energy savings: Lower energy use, fewer emissions, and potential savings in utility bills year after year
• Future-proofed: Designed to meet and exceed the upcoming 2026 Energy Code requirements and align with Energy Star and Zero Energy Ready Homes
• You can learn more about our EcoSmart™ Studs here, or contact us to get on the priority list.

 

Common Mistakes to Avoid

When taking on framing and insulating exterior walls, there are a lot of ways to make mistakes. To help avoid those mistakes, talk to your local Building official and make sure to get your work inspected. Most inspectors are willing to work with home owners who are willing to learn.

Some of the most common mistakes include:

• Misaligned studs
• Using unrated or multiple vapor barriers used that will trap moisture in the exterior wall
• Sheathing nails that miss the studs
• No moisture or water barrier installed
• Installing multiple vapor barriers that trap moisture
• Incorrect or missing flashing around windows or doors

Avoiding these mistakes early saves you time, money, and headaches down the line.

 

Final Thoughts & Pro Tips

If you’re serious about learning how to do DIY building projects, start small and build your skills over time. Try an interior, non-load-bearing wall or create a garden shed, workout area, office space or small garage in your backyard that is unattached to the main structure.

These projects are great introductions to everything we’ve discussed in framing, insulation, sheathing, moisture management and are budget-friendly if you’re doing the labor yourself.

 

FAQs

How far apart are wall studs?

Most are 12″, 16″, or 24″ on center.

 

What’s the best insulation for interior walls?

It depends, but natural fibers, recycled materials, or a Flash and Fill mix are excellent choices. For DIY, hemp batts are especially good.

 

Can I reuse old insulation?

Maybe. It depends on the type, condition, and age. Some older insulations are now considered hazardous. When in doubt, consult a pro.

 

Is it better to insulate before or after drywall?

For walls, before drywall goes up is best. For attics, drywall may be installed first and insulation blown in later as part of a vented attic system. Read more here.

Looking to learn more? Check out our guide on How to Construct a Stud Wall: A Guide to Wall Studs and Exterior Wall Framing Wall Studs.