Founder | BPI® Energy Auditor Certified Professional
Attic top plates are one of the most common places for air leaks in a home.
Air leaks can quickly lead to 30% more heat loss, so it’s essential to seal them up! Luckily, it’s a quick and easy fix with the right tools.
Sealing attic top plates is a simple way to prevent air leaks in the house, resulting in lower energy bills and comfortable living spaces. You need caulk and a caulk gun or spray foam cans to seal them. With the right tools, it’s a quick and easy fix that will make your home more energy-efficient.
Proper sealing of attic top plates can be the difference between cold drafts in your living space and a comfortable, well-insulated home.
It’s therefore essential to learn how to do it right!
Here’s everything you need to know about sealing attic top plates, plus the tools you’ll need to get the job done quickly and efficiently.
What Tools, Caulk or Spray Foam Can To Use for Sealing the Top Plate?
Like any home improvement project, you’ll need the right tools to complete the job correctly. Here are the tools you’ll need for sealing attic top plates:
- Caulk: This is the critical material you’ll need to seal any cracks or gaps less than 1-quarter inch wide. Choose a high-quality caulk that’s specifically designed for sealing air leaks. When properly applied, caulk can last up to 5 years without needing to be replaced.
- Caulk Gun: You’ll need a caulk gun to apply the caulk. You must ensure a uniform and adequate caulk application to achieve a proper seal. Caulk guns are relatively inexpensive and easy to use.
- Spray Foam: If you’re sealing larger cracks or gaps, you’ll need to use spray foam instead of caulk. Spray foam is a thick, viscous material that expands 30-60 times to fill any space it’s applied to. It also deters moisture which can lead to mold and mildew growth.
- Utility Knife: For proper adhesion, you’ll need to remove any old caulk or sealant from the surface before applying new caulk or spray foam. A utility knife can help you remove old caulk quickly and easily.
Now that you have the tools you need let’s look at how to seal attic top plates properly.
How Do You Insulate A Top Plate?
To insulate a top plate, you’ll need to seal any cracks or gaps around it. You can do this with caulk, spray foam, or weather stripping. Once the cracks and holes are filled, you can insulate the area with fiberglass, cellulose, or spray foam.
Air leaks around attic top plates can cause drafts and energy loss in your home, pushing your utility bills up.
Properly sealing attic top plates will block drafts and make your home more comfortable and energy-efficient. Here’s how to do it:
1. Inspect the Area Around Your Attic Top Plates
You’ll need to check the top plates for cracks where air can escape. These are the areas you will need to seal.
Check the inside and outside of your attic top plates for any gaps, and note their sizes. If the hole is significant, you better use foam instead of caulk to mitigate the risk of air leaking.
2. Clean the Area Around the Cracks or Gaps
Once you’ve located the gaps, clean the area around them with a putty knife or utility blade.
This will help the new caulk or spray foam to adhere correctly. Scrape away any old caulk, paint, or sealant and remove any debris.
You should also clean it with a damp cloth and some cleaning fluid to ensure the area isn’t contaminated with pathogens or mold spores.
Dry the area thoroughly before proceeding. You don’t want to seal in moisture as this can lead to mold and mildew growth.
3. Apply Caulk To Cracks or Gaps Less Than 1-Quarter Inch Wide
For cracks or gaps less than 1-quarter inch wide, use caulk.
Hold the caulk gun at a 45-degree angle and apply an even bead of caulk along the length of the crack or gap. This will help get caulk deep into the crack or hole for a better seal.
The best way to apply caulk to prevent gaps in the seal is to use one continuous hand movement. This prevents any cracks from being missed.
Use your finger or a putty knife to smooth the caulk and remove any excess. Wipe away any caulk that gets on surfaces you don’t want to be sealed.
4. Apply Spray Foam To Cracks or Gaps Larger Than 1-Quarter Inch Wide
For larger cracks or gaps, you’ll need to use spray foam. Spray foam comes in a can with a nozzle attachment.
To apply, hold the can upright and aim the nozzle at the crack or gap. Carefully depress the trigger to dispense the foam.
The foam will expand 30-60 times its original size, so be sure not to overfill the space. Use a putty knife to smooth out the foam and remove any excess.
5. Inspect Your Work and Repeat As Needed
To ensure a proper seal, inspect your work after you’ve applied the caulk or spray foam.
If you see any missed cracks or gaps, repeat the process until all cracks and crevices are sealed. You may need to apply additional caulk or foam to seal everything properly.
6. Let the Caulk or Spray Foam Dry
Once you’ve applied the caulk or spray foam, let it dry for 24-48 hours before painting or staining. This will give the caulk or foam time to set and achieve a proper bond.
However, temperature and humidity will affect the drying period, so check the manufacturer’s instructions for more specific drying times.
Benefits of Sealing Attic Top Plates
If you love saving money and being more energy-efficient, you’ll love the benefits of sealing attic top plates.
By sealing cracks and gaps around your attic top plates, you can:
Save Money on Your Energy Bills
Sealing attic top plates can help you save money on your energy bills.
Drafty homes are less energy-efficient, so sealing the cracks and gaps around your attic top plates can keep heat in and lower energy costs.
It also reduces the strain on your HVAC system, which can help improve efficiency and prolong its lifespan.
Improve Your Home’s Indoor Air Quality
A stuffy, musty attic can lead to poor indoor air quality. This can lead to headaches, nausea, and other health problems.
By sealing the cracks and gaps around your attic top plates, you can improve airflow and prevent stagnant air from seeping into your home. This will help you breathe easier and improve your overall health.
The air within your attic tends to seep into other areas of your home. This can mean your poorly insulated attic space is effectively impacting the air quality in the rest of your home.
Mold spores and other nasty pathogens can enter your home through an unsealed attic space – problems that can exacerbate respiratory problems in those who live in the house.
Prevent Pests From Entering Your Home
Pests love nothing more than a cozy home to nest in. Once they set up shop in your attic, they can increase in numbers and damage the fabric of your building, potentially weakening it.
This can lead to a severe infestation that can threaten your home’s cleanliness. Sealing the cracks and gaps around your attic top plates will help keep pests out of your home and protect your family from their harmful effects.
Keep Moisture Out
Attics are susceptible to moisture damage due to their location and lack of ventilation.
When moisture seeps into your attic, it can cause wood rot, mold growth, and other serious problems.
By taking steps to seal the cracks and gaps around your attic top plates, you can help prevent costly water damage and keep your attic dry.
Reduce Noise Pollution
If your attic is full of cracks and gaps, it can amplify noise from outside and make your home feel less peaceful.
Ensuring your home is adequately sealed will dampen exterior noise from cars and other sources.
This helps increase productivity, concentration, and overall happiness, effectively making your home a much nicer place to live.
How Do You Seal a Wall Plate?
To seal a wall plate, apply caulk or spray foam around the perimeter. You can also use weather stripping to fill any gaps or cracks. Smooth the caulk or foam with a putty knife, then press the wall plate against the wall. Hold it in place for a few seconds to allow the adhesive to set.
Sealing a wall plate helps prevent drafts and energy loss. It also keeps pests and moisture out of your home. Follow these simple steps:
- Apply a layer of caulk or spray foam around the perimeter of the wall plate.
- Smooth the caulk or foam with a putty knife or your finger.
- Press the wall plate against the wall and hold it in place for a few seconds. The adhesive will set, and the wall plate will be sealed.
How Much Does It Cost to Seal An Attic?
Generally speaking, it can cost around $4,500 to seal an attic if you have it done professionally. This typically includes the sealing of the entire attic space.
If your attic is relatively small, you can expect to pay less, which may cost you around $1,000. However, if you’re doing it yourself, you can expect a much lower cost than this.
The only issue with doing it yourself is that you might make mistakes – mistakes that will cost you down the line when you call in a professional to fix them.
Typically, new builds come with a government-mandated amount of insulation, so you may not need to replace the insulation fully.
However, if your home is older, you may need full professional services to bring it up to standard – effectively costing you more.
Final Thoughts
Sealing your attic top plates is an essential part of maintaining your home.
Not only does it help improve your home’s energy efficiency, but it also helps prevent pests and moisture damage.
You will need to use caulk or spray foam to seal the cracks and gaps around your attic top plates.
By taking the time to seal the cracks and gaps around your attic top plates, you can save yourself money and headaches in the long run.
If you choose to have a professional seal your attic, you should bear in mind that the costs will go up.
If you found this article useful, you might also be interested in reading our other article, “Air Sealing Your Home For Efficiency: Your Ultimate Guide“, which takes a comprehensive look at air sealing your entire home.