Skip to main content
Questions? Call!

Attic Air Sealing & Insulation

Although not always the cost effective solution, two-part spray foam air seals
and insulates unlike most insulation solutions which do not act as a proper air barrier.


Effective Insulation is Two Parts
Regardless of which material and application is used, insulation is not fully effective unless it is properly installed and fully aligned with a contiguous air barrier. Insulation works because it incorporates air pockets that resist the flow of heat, or slows the conduction of heat. This resistance to heat flow is measured by the R-value of the material. 

Most insulation  (with the exception of spray foam and rigid foam board) does not stop air flow.   Most cost effective insulation solutions require a separate air barrier or "skin" to stop the flow of air. For the air barrier itself to be effective, it must be contiguous and continuous across the entire building envelope, with all holes and cracks fully sealed, and it must be perfectly aligned with the insulation. 

You need both parts of the jacket to make it work the best.  The same goes for the insulation around the house.

Insulation & Air Barrier 
Must be Aligned

All Six Sides of the Home
Most Insulation is Wrong

Missing Air Barrier

Attic air sealing and insulation Maryland

A Common Issue:

Insulation does not act as an air barrier
and is less effective as a result.

Air Barrier Installed

Proper air sealing and insulation Maryland

The Solution:

For insulation to be most effective, gaps
around the existing air barrier (drywall,
flooring, framing, etc.) must be sealed up.

Proper Insulation Treatment


Are these issues on your mind? 

Too cold downstairs in winter?
Does your AC run all day in summer?
Does your heat run all day in winter?
Do you have enough attic insulation?
Are your HVAC ducts properly sealed?
Do you have drafts in your house?

Proper insulation treatment, including air sealing and following recommended R-Value guidelines, can solve all of these issues!

Think in Terms of Jackets... 
Attic air sealing and insulation Maryland

*A jacket has two parts that make it work best. 
*The zipper and the thick layer.
*If the zipper is open air can get in 
*Insulation is similar and needs two things
*Air sealing and proper insulation

Air sealing (zipper)

Makes insulation most effective.
Most homes have two or more major bypasses.  


Insulation (coat liner)

Insulation is not designed to stop the flow of air.
Most homes are under insulated. 

How to Beat the Summer Heat

Comfortable summer home

Thermal image of a ceiling that is missing insulation taken during summer.  The heat from the hot attic radiates rapidly into the home if insulation is mis-aligned.

Temperatures in the attic during summer months can be between 150-160 degrees.  It is a brutal place with stifling air and high amount of humidity.  When an attic is not properly vented, air sealed and insulated the building heat and pressure in the attic forces radiant heat through the drywall and slowly, steadily and surely into the house.  

Consider this:

Homeowners that have a minimum insulation level in the attic equal to R-19, reflective roof shingles and proper ventilation can experience up to two-thirds less solar heat gain than those with characteristics such as little to no insulation, dark roofing shingles and no attic ventilation. 

Summer remedies for the attic include: proper ventilation intake, proper baffle installation, proper insulation levels, proper air sealing, rim joist/ crawl space air sealing and insulation.

How to Take Hold of the Winter Cold

In the winter, the heat runs warm air through ducts to increase the temperature inside.  As the temperature decreases outside the pressure in the house increases and it is a well known fact that warm air rises and when it does it gets pushed through cracks and crevices at the ceiling and other less well known areas known as exfiltration points.   For this issue it is critical to have air sealing completed so that the warm air that you are paying for has nowhere to go when it is cold outside!

Equally important to the warm home in winter is to have the right amount of insulation to prevent radiant heat from traveling from inside through the wall and into the attic or other areas of the home touching the outside.  By slowing the transfer of heat with insulation it helps to keep the inside (envelope) "bundled up" like the layers of a nice winter coat.

Winter Month Key Measures

Zip Up Big Thick Layer
Holes Identify Thermal Boundary
Crevices Kneewalls
Cracks Attic Floor
Bypasses Slopes
Overhangs Crawl space
Floor Bypasses Rim Joist
The One - Two Punch! 

1. Air Sealing an Attic

Attic air sealing company Maryland

This typical Maryland attic is getting air sealed around
existing insulation prior to having insulation blown to R-49

2. Loose Fill Cellulose Insulation

Attic insulation company Maryland

After air sealing an attic,
we use loose fill cellulose to insulate.

Here is why:

Good Fungicide
Good Fire Retardant
Maintains Best R-Value in Winter
Cellulose is an Air Retarder
Made From Recycled Materials
His a High R-Value Per Inch

Well insulated attic Maryland

Well insulated attic with loose fill cellulose.

Healthy vs. Unhealthy Summer Attic

Healthy attic vs. unhealthy attic Maryland climate

Air Sealing an Attic is Key for Winter

Air sealing and insulation Maryland

Attic Exfiltration Points
1. Plumbing vent bypass
2. Chimney bypass
3. Attic access hatch
4. Interior wall top plate
5. Electrical box bypass
6. Duct chaseway
7. Exterior wall top plate

    Specialized Maryland Contractor
    • MHIC Licensed
    • Building Analyst Certified
    • Envelope Professional Certification
    • EPA Lead Renovator Certified


    Hometrust Remodeling's mission is to help Maryland homeowners create a more comfortable home and save energy by using building science principles and modern air sealing and insulation techniques.

    Google Reviews

    Services & Service Areas

    Calvert County, Carroll County, Anne Arundel County, Baltimore County, Howard County, Montgomery County, Prince George's County

    Contact Us
    our facebook page youtube

    MHIC License # 114593
    Approved BGE Energy Contractor
    Approved Pepco Energy Contractor


    Hometrust Remodeling
    North Laurel, MD 20723
    Hometrust Remodeling

    Trust us to put all the pieces together right! 
    ©2021 Hometrust Remodeling | All Rights Reserved

    An Energy Auditor's Purpose 
    "Energy auditors visit residential buildings and talk to owners and residents.  They inspect, test, and measure to decide what energy-efficient retrofits are practical and cost effective." Residential Energy