If you’re looking to put the finishing touches on your home, insulating basement walls is an essential step in making that space more livable. Once your walls are fully insulated, your heating and cooling costs will drop significantly, as heat transfer is slowed thanks to your basement drywall insulation.
A finished basement can add hundreds of square feet to your property, which also increases the value of your home while creating either extra storage space or a spare room for your family.
Installing insulation in a basement is not an easy job, but it’s manageable if you plan to DIY, or with help from friends or family. So if you're wondering how to cover basement walls with sheets or install rigid foam board insulation in your basement, read on for our step-by-step guide to insulating basement walls.
Insulation Options for Basement Walls
When you’re insulating basement walls, you can choose between these three materials:
This material provides great R-value, offers a vapor barrier, and easily covers wires, pipes, and other utilities making it a good choice for insulating basement walls. Once cured, spray foam also can fill gaps, which can also help increase structural stability.
Rigid Foam Boards
Foam boards are cheaper than spray foam and often less messy to work, making the material more DIY-friendly. They have a good R-value and insulate well provided you seal gaps between boards with tape and/or mud. Some rigid foam boards include insulation with a vapor barrier in one, which helps you avoid using plastic sheeting as a moisture barrier.
Hybrid Fiberglass and Foam Board System
This material is cheaper than spray foam and foam boards, has a good R-value and is easy to install, but it performs least well in basements, particularly as an air-sealing material.
Tips Before You Start This Project
The most crucial issue to address before insulating basement walls is moisture. You’ll need to make sure there is no moisture in the walls. The easiest way to check is to head to your local hardware store and purchase a moisture meter tool. You can usually find a good one for under $50. You'll also need duct tape and waterproof sheeting (this material is similar to house wrap). Waterproof sheeting can help you avoid moisture buildup and the potential for mold or mildew.
If you have determined that the walls of the basement are moisture-free, your first step will be to tape up the waterproof sheeting to your concrete wall with an impermeable duct tape border and then leave it there for 48 hours. The sheeting serves as a vapor barrier.
After two days have passed, inspect the sheeting for signs of condensation. If you spot any droplets, it means water is somehow seeping into your basement. Note: You should consider using a vapor and rigid foam board material if moisture is any kind of concern in your basement.
You’ll also want to check if your basement has tie rod holes, and if so, you need to ensure they are sufficiently sealed. When a house is built, small steel rods provide support while the concrete is settling. The rods are sometimes either left in place, but if they are taken out, they leave small holes in the walls. These holes are prone to leaking and can often lead to a flooded basement. You will need to waterproof any tie rod holes before you insulate your basement. You can use hydraulic cement to fill the tie rod holes.
How to Insulate Basement Walls
For the example in this article, we'll be using rigid foam board insulation. These steps do not provide for possible variables you may come up against at your house, so be sure to supplement this information with online video sources, or consult an expert at your local hardware store for unexpected issues that could be beyond the basics.
1. Choose your insulation: When picking insulation, consider its R-value (a measure of how efficiently the insulation reduces heat exchange.) In colder climates, opt for an R-value of at least 60. In warmer temperatures, an R-value of 30 or above will suffice.
2. Seal your foundation walls: Before insulating basement walls, caulk and spray foam any cracks or gaps between the framing and masonry. Additionally, be sure to seal around any exposed wires or pipes.
3. Glue foam insulation to foundation walls: First, make sure you use glue that is manufactured for rigid foam board insulation. Cut your foam board into properly fitting pieces and tightly fit them against the rim joints of your foundation walls, then glue them into place. You may be able to use pre-cut panels for your project. Fill in the gaps with smaller pieces of foam board.
4. Frame out the walls: Using chalk, draw a line four inches from the wall around the entire basement. Next, cut out the top and bottom plates to fit around the walls. For the bottom plates, use weather-treated lumber or composite decking material to protect against moisture.
5. Install blocking: Add blocking between the first floor joists so you can secure the top plates to it.
6. Install studs: Use studs to secure the top and bottom plates.
7. Install fiberglass batts: Install blanket insulation throughout the basement area.
8. Cover the installation with drywall: Taping and mudding skills come in handy for wrapping up this step for a truly finished basement.
How to Frame Around Ductwork in a Basement?
You may have ductwork that you need to work around to properly drywall your basement. If you do, you’ll need to build a frame around it before you can continue. These steps offer the basics of installation, but do require some carpentry skills and the proper tools to complete:
1. Measure the duct to determine the size of the frame you'll require.
2. Create some soffit ladders on the ground using 2x2s. (Cut four 2x2s to the length of the duct for the top and bottom plates).
3. Attach all the pieces of the ladders. Use a triangle or speed square to ensure that you create a perfectly square structure.
4. To finish the frame, mark some 2x2s to fit across the bottom of both ladder sections, spaced to the duct's width with 1 inch on each side for clearance.
5. Lift the finished frame and place it around the duct. Screw or nail in the top plates to the ceiling joists so that they're secure.
6. Finish the job by covering the frame with drywall.
Best Insulation Boards for Walls
When it comes to insulating basement walls or even crawl spaces, rigid foam insulation boards are always a solid choice of material.
Rigid foam insulation also acts as an air barrier when the boards are sealed at edges and joints with tape. These panels are available in various widths and thicknesses and are a cost-effective, efficient option for basement insulation.
Protection of a Home Warranty
Here at First American, we offer a range of home warranty plans to help protect your budget when covered appliances and home systems break down unexpectedly. Contact us to get a free home warranty quote today.
The contents of this article are provided for general guidance only. First American Home Warranty does not assume any responsibility for losses or damages as a result of using this information.