Knee Walls In Attic: A Comprehensive Guide

If you have an attic in your home, you may have noticed that there are sections of the walls that are not quite vertical, but rather slope inward. These are known as knee walls, and they can be found in many older homes.

While they may seem like an odd architectural feature, knee walls can actually serve a number of practical purposes, from providing additional storage space to improving energy efficiency.

If you are considering adding knee walls to your attic, or if you simply want to learn more about this unique feature, you have come to the right place.

In this comprehensive guide, we will cover everything you need to know about knee walls, from the basics of what they are and why they are useful, to the different types of knee walls and materials you can use, to step-by-step instructions for installing knee walls yourself or hiring a professional to do it for you.

So read on to learn more about this fascinating architectural element and how it can enhance your home.

Understanding the Basics of Knee Walls

You’re gonna love how knee walls make use of your attic space, giving you a whole new room to enjoy! Knee walls are short walls that are installed in attics to create usable space. They are called knee walls because they are typically around knee height.

Knee walls can be made from a variety of materials, including wood, drywall, and even insulation. They are often used to partition off an area of the attic for storage, or to create a new room.

Knee walls can also be used to provide additional insulation to your home, as they help to keep the hot air in during the winter and the cool air in during the summer. When installing knee walls, it is important to ensure that they are properly insulated. This will help to prevent air from escaping through the walls and into your home.

Additionally, knee walls should be properly ventilated to prevent moisture buildup. With proper installation and ventilation, knee walls can be a great addition to your home, providing you with extra space and helping to keep your home energy-efficient.

Types of Knee Walls

If you’re a homeowner, chances are you’ve come across different styles of these short walls that divide your living space. Knee walls, as they’re commonly referred to, can be found in many homes, and they come in different types. Knowing the different types of knee walls can help you determine the best one for your home.

  1. Half-height knee walls: These are the most common type of knee walls and are typically about three to four feet tall. They’re used to separate attic space from living space and can also be used as a support for a staircase.

  2. Full-height knee walls: These knee walls extend all the way to the ceiling and are mostly used for dividing rooms or creating a separate space in the attic. They’re often used in areas where there’s not enough headroom to stand, and they provide additional storage space.

  3. Angled knee walls: These knee walls are designed to fit in areas with sloping or angled roofs. They’re typically installed in attics and can be used to create a separate living space or storage area.

  4. Rounded knee walls: As the name suggests, these knee walls are rounded at the top and are mostly used for aesthetic purposes. They add a unique architectural design to the room and can be used to create a cozy and intimate space.

Understanding the different types of knee walls available can help you choose the right one for your home. Whether you need additional storage space or you’re looking to create a separate living area, there’s a knee wall that’ll suit your needs. Talk to a professional contractor to help you make the best decision for your home.

Materials for Knee Walls

When choosing materials for your knee walls, it’s important to consider the overall style and design of your home. You want the materials to complement the aesthetic of your house while also being durable and efficient. Here are some materials commonly used for knee walls:

Material Description Pros Cons Cost
Fiberglass Insulation Made of fine glass fibers, it comes in batts or rolls Good insulation Can be itchy and requires protective gear for installation $0.64-$1.19/sq.ft
Rigid Foam Insulation Made of polystyrene or polyisocyanurate foam board Provides better insulation than fiberglass More expensive than fiberglass $1.07-$2.20/sq.ft
Plywood Strong, durable and can be painted or stained Can add structural stability Not as good insulation as other materials $0.66-$1.05/sq.ft

Other materials that can be used for knee walls include drywall, tongue-and-groove boards, and beadboard. It’s important to choose materials that not only fit your style but also provide good insulation for your home. Consult with a professional to determine the best materials for your specific situation.

When it comes to knee walls, choosing the right materials is crucial. You want something that not only looks good but also provides good insulation and structural stability. Consider the different materials available and their pros and cons before making a decision. Don’t be afraid to consult with a professional to ensure you make the best choice for your home.

Tools Required for Installing Knee Walls

To properly install knee wall insulation, you’ll need a few tools that will make the process easier and more efficient.

The first tool you’ll need is a utility knife. This will come in handy when you’re cutting insulation to size, and you’ll need it to cut through the insulation itself. It’s important to have a sharp utility knife on hand, as a dull blade can make the process more difficult and time-consuming.

Another tool you’ll need is a staple gun. This will be used to attach the insulation to the knee wall studs. Make sure you have plenty of staples on hand before you begin, as you don’t want to run out midway through the installation process. Additionally, you’ll want to make sure the staple gun is in good working order, as a malfunctioning staple gun can slow down the installation process significantly.

You’ll need a measuring tape. This will be used to measure the length and width of the knee wall space so that you can cut the insulation to the correct size. It’s important to take accurate measurements to ensure that the insulation fits snugly and doesn’t leave any gaps that could allow air to escape.

With these three tools on hand, you’ll be well-equipped to install knee wall insulation efficiently and effectively.

DIY Installation Guide

You can easily install insulation in the space between your home’s sloped ceiling and the floor of the attic using just a few basic tools and some simple steps. Here’s how to do it yourself:

  1. Start by measuring the length and width of the space between the ceiling joists. Cut your insulation to fit snugly between the joists, leaving a small gap between the insulation and the roof deck to allow for ventilation.

  2. Next, use a staple gun to secure the insulation between the joists. Be sure to avoid compressing the insulation, as this can reduce its effectiveness. You can also use a utility knife to trim any excess insulation around the edges.

  3. For added protection, you can also install a vapor barrier over the insulation. This will help prevent moisture from penetrating the insulation and causing damage. Simply staple the barrier to the joists, being careful not to puncture it with any staples.

  4. Finally, be sure to wear protective gear, such as gloves, a mask, and safety glasses, when installing insulation. This’ll help prevent irritation from the materials and keep you safe while working in the attic.

With these easy steps, you can improve the energy efficiency of your home and enjoy a more comfortable living space.

Hiring a Professional Contractor

Hiring a professional contractor can save you time and ensure that the insulation in your home is installed correctly. While installing knee walls in the attic may seem like a straightforward task, there are many factors to consider, such as the type of insulation to use and the proper ventilation required. A professional contractor has the experience and knowledge to ensure that the job is done right the first time, saving you the hassle of having to redo the work yourself.

When hiring a professional contractor, it’s important to do your research and select someone who is licensed, insured, and reputable. You can check with your state’s licensing board to verify the contractor’s credentials and look for reviews online to see what others have to say about their work. Additionally, it’s a good idea to get multiple quotes and ask for references before making a final decision.

To give you an idea of what to expect when hiring a professional contractor to install knee walls in your attic, here is a table outlining the average costs associated with the job:

Task Average Cost
Insulation installation $1.50-$3.50 per square foot
Ventilation installation $300-$500
Labor and materials $1,000-$3,000

Keep in mind that these costs can vary depending on the size of your attic and the specific materials used. However, having a general idea of what to expect can help you budget accordingly and ensure that you are getting a fair price for the work being done.

Maintenance and Upkeep of Knee Walls

Ensuring proper upkeep of knee wall insulation is essential for maintaining a comfortable and energy-efficient home. Here are some tips to help you maintain and improve the insulation in your knee walls:

  1. Inspect your knee walls regularly: Check your knee walls at least once a year to make sure there aren’t any leaks or damage to the insulation. If you find any issues, fix them immediately to prevent further damage.

  2. Keep the area clean: Clean the area around your knee walls regularly to prevent the accumulation of dust, dirt, and debris. This will help keep the insulation in good condition and prevent any damage from occurring.

  3. Add more insulation if needed: If you find that the insulation in your knee walls isn’t sufficient, add more to improve the energy efficiency of your home. You can do this yourself or hire a professional to help.

  4. Use the right type of insulation: Make sure the insulation you use is appropriate for the type of knee wall you have. For example, if you have a sloped roof, you may need to use a different type of insulation than if you have a flat ceiling. Use the right type of insulation to ensure maximum efficiency and comfort in your home.

By following these tips, you can ensure that your knee walls are well-maintained and efficient, keeping your home comfortable and energy-efficient throughout the year.


So, now you have a better understanding of knee walls in attics and their importance. Installing knee walls can be a great way to maximize your home’s storage space and even increase its energy efficiency. By choosing the right materials and following the proper installation techniques, you can create a sturdy and reliable knee wall that will last for years to come.

If you’re confident in your DIY skills, you can certainly tackle the installation process yourself. Just make sure to gather all the necessary tools and materials beforehand and follow the step-by-step guide carefully. However, if you’re unsure about any part of the process, it’s always best to hire a professional contractor to ensure that the job is done correctly.

With proper maintenance and upkeep, your knee walls will continue to serve you well for many years to come.