Dec 14, 2019

Exploring the Science Behind Ice Dams

Learn all about the science of ice dams on your home from Barry Strandz, a professional and educator with over 30 years experience in the home remodeling industry.

Listen To The Entire Home Improvement Show Here:

What Causes Ice Dams?

Home with a large number of icicles hanging from the roo

There are always two issues that cause ice dams: a lack of insulation or a lack of ventilation.  One of the most visible ice dam warning signs is a high volume of icicles on your roof edge.  Story and a half homes have a heightened risk for ice dams because of their architecture.

Homeowners with ice dam issues often notice that their lower level living areas are colder than upper levels.  Story and half homes built in the 1980’s face a unique challenge because the roof trusses provided minimal space for insulation, particularly near the outside walls.

Oftentimes, blown-in cellulose was used and many homes could have benefited from additional insulation at the time of installation.  Without enough insulation, the home’s internal heat migrates up from convection to the top of the roof, providing that area with the highest concentration of warm air.   This means that a sizable amount of heat is working its way through the assembly of the insulation up past the decking and onto the roof surface, melting the snow cover exacerbating an ice dam problem.

Working with a reputable insulation contractor that uses diagnostic testing, such as FLIR imaging, can allow them to identify temperature differentiations within your home, pinpoint the source, and propose steps towards addressing the situation.

Learn More About the Diagnostic Testing Contractors Use to Pinpoint Home Energy Deficiencies:

How to Address Ice Dams

In story and a half homes, the best method for addressing ice dams is the creation of a hot roof.  To create a hot roof, insulation is installed near the roof sheathing and is closed off to outside air flow.  When compared to vented roofs, hot roofs have a slightly higher roof temperature.

When an attic is filled with spray foam insulation to produce a hot roof, the attic’s temperature rises because the thermal envelope is shifted underneath the roof, due to ventilation being absent.  The creation of a hot roof equates to energy savings because a home is prevented from leaking air through the roof.

Lindus Construction team member installing insulation on a Twin Cities roof

When it comes to building sciences, many professionals hold the belief that homes are too tight today, which has led to the creation of moisture and mold problems.  Even though historic homes rarely have moisture and mold issues, houses are not meant to breathe through their walls and attic spaces, as was the case with historic homes.  A common characteristic of turn of the century homes is that their doors and windows lacked adequate weatherstripping.  This meant the average 1000 square foot home in 1900 would have the equivalent of two whole house air changes per hour due to leaky windows, doors, and attics.  Once this was recognized, building code changes were implemented.

However, as the level of insulation and air sealing in exterior walls began to increase, the ability for walls to breathe was compromised.  Water vapor within the home began to rise to the attic space.  Without the ability for water vapor to exit the attic, frost begins to form.  Once temperatures rise and the frost melts, it dampens the home’s insulation, rendering it useless.  In addition, the home’s air quality is compromised.

To circumvent this issue, air exchange systems were introduced.  Heat recovery ventilators are systems that ventilate the house, while gaining the heat back.  This happens when outgoing air which was warm gives its heat to the fresh air coming in. As that air exchanges, the result is preheated fresh air coming into the home, lowering the strain on the furnace. 

Contact us today to get started on your home’s roofing or insulation project.

Our team answers homeowner questions every weekend on WCCO 8:30 AM from 9:00 am-10:00 am.  Have your most pressing home improvement questions answered by calling or texting 651.461.9226.

Browse Our Insulation & Ventilation Projects:

Our Insulation & Ventilation Reviews:

"I was very happy with the free insulation estimate I received from the Lindus rep. He took the time to walk me and my father-in-law through a thermal scan of all the leaky spots in my attic - and basement, bonus! - and was honest and forthright about the work they do and the best and most economical options available to us to improve ambient temperature control in these areas."

Rima F.
Lake Elmo, MN
January 9, 2024

"Lindus Construction did a great job of removing old insulation in our attic and then sprayed foam insulation to seal the air leaks in both our attic and basement. They then installed new insulation to meet current building codes and corrected venting issues. Randall kept me updated me updated at each step of project which I appreciated. The Lindus team was very courteous and did great job of keeping our house clean during this time."

Ken M.
Cottage Grove, MN
November 22, 2023

"Randall Bowman and an attic insulation crew attended to my Somerset, WI condo in Oct. 2023.  They were ahead of schedule, very conscientious about not causing any damage or mess in the house. Very conscientious about not blocking traffic for my condo development neighbors. And, they were very efficient-- finishing earlier than they estimated. I would highly recommend Lindus Construction and the two insulation company they contract with."

Deb M.
Somerset, WI
October 12, 2023

"Fourth project with Lindus. Brandon Larson analyzed issues that occurred last winter.  He came up with a plan to prevent them from happening again."

Jane S.
Solon Springs, WI
August 7, 2023

"Great job! Kept us informed! Also, was very considerate. Made sure everything was cleaned up at the end of the day and took care to always wear masks around us, since my wife is immune compromised."

Dave G.
Maplewood, MN
June 26, 2023

"I thought it went very well!  No issues."

Brian B.
Ramsey, MN
August 24, 2023
Contact Us To Schedule A Complimentary Estimate. Receive A Heat Map Analysis With Insulation Estimates Through April 30th.
Some restrictions may apply. Call for details.