Being a homeowner in Minnesota means understanding the different aspects of building codes and what they mean for you. To guarantee legal compliance, safety, and the endurance of your roofing system, it is essential that you understand the building codes related to roofing, whether you’re planning new roof installation, replacement, or repairs.
To help you out in making the best decisions for your roof we will introduce you to some of the most important Minnesota roofing codes throughout this blog post, with emphasis on important details that all homeowners should be aware of.
What Are The Minnesota Roofing Codes?
The 2020 Minnesota Residential Code, which aligns with the 2018 International Residential Code, is one of the most important parts of the state’s construction codes that regard roofs. This guideline guarantees the safe and efficient construction of roofing systems while considering Minnesota’s particular temperature and environmental circumstances.
Many of Minnesota’s building codes have been implemented in response to the difficulties presented by severe winters, which include large amounts of snow and ice accumulation that can cause problems like ice dams, leaks, and structural damage if roofs are not properly designed and constructed. Therefore, the Minnesota building codes regarding roofing are dedicated to advancing building methods and strengthening a home’s ability to withstand these weather-related difficulties.
Key Parts Of Minnesota’s Building Codes
General Requirements
1. Building Permits
Before starting a roofing project, homeowners need to get a building permit from their local government. This usually means submitting plans and paying a fee to local building departments, along with allowing them to inspect the project at various stages in order to make sure it follows the code.
2. Materials
All roofing materials must be installed according to Chapter 9 of the 2020 Minnesota Residential Code and the manufacturer’s instructions. Common materials include asphalt shingles, metal roofing panels, wood shakes, and tiles, each with specific installation requirements.
More Specific Material and Installation Standards
1. Roof Slope
The roof’s slope affects which materials and techniques can be used. For example, asphalt shingles can only be used on roofs with a slope of 2:12 or greater. For slopes between 2:12 and 4:12, extra measures like double underlayment are also needed to prevent issues with water and ice.
2. Ventilation
Proper roof ventilation is required, especially in enclosed attics and rafter spaces. The code requires at least 1 square foot of ventilation for every 150 square feet of attic space. This includes cross ventilation with openings protected from rain and snow using corrosion-resistant materials.
3. Ice Barrier Requirements
To guard against ice dams and water infiltration, a self-adhering, polymer-modified bitumen sheet (ice barrier) must be installed from the eaves to at least 24 inches beyond the interior wall line.
4. Decking Requirements
The roof deck must have solid decking with materials like plywood or oriented strand board (OSB) to support the roofing system and prevent sagging.
5. Underlayment
Underlayment is a secondary barrier against water. The code requires underlayment that meets ASTM standards, with specific requirements based on roof slope. For slopes less than 4:12, at least two layers of underlayment are needed.
6. Fasteners
Asphalt shingles must be secured with at least four galvanized roofing nails per shingle. These nails need to penetrate the roof decking or underlying material at least ¾ of an inch, ensuring that the shingles are firmly attached and can resist wind uplift and other forces.
Specific Installation Guidelines
1. Existing Roofs
In some cases, new roofs can be installed over old ones without removing them as long as the new roof transmits loads directly to the building’s structure. However, you can’t install metal panels over wood-shake roofs, according to Section R908.
2. Flashing and Leak Prevention
Flashing is essential for preventing water from entering the roof at vulnerable spots like valleys, pipe penetrations, vents, skylights, and more. The code requires that valley flashing be at least 24 inches wide and made from corrosion-resistant materials to divert water and protect against leaks effectively.
3. Inspection and Compliance
Regular inspections ensure the roofing work complies with the building codes. This includes checking the structural integrity, proper installation techniques, and adhering to ventilation and drainage requirements.
4. Manufacturer’s Instructions
The code emphasizes the importance of following the manufacturer’s instructions for installation. If the code and the instructions conflict, stricter requirements must be followed to ensure the roof performs well and meets safety standards.
Installation and roofing materials must follow manufacturer directions and Chapter 9 of the 2020 Minnesota Residential Code. This code is enforced statewide under Minnesota Statute 326B.121 and is based on the 2018 International Residential Code (IRC).
Also Read: How to File a Hail Damage Roof Insurance Claim in Minnesota
Why the Roofing Codes Matter
1. Promised Safety
The main goal of building codes, including roofing codes, is to ensure the safety of buildings and the people in them. Following the Minnesota state roofing codes helps ensure roofs are installed correctly, reducing the risk of leaks or structural failure.
2. Longevity
When roofs are installed according to the code, they last longer. Code-compliant roofs can better handle Minnesota’s tough weather, like heavy snow, rain, and strong winds.
3. Legal Requirements
Not following roofing codes can lead to fines, penalties, and problems when selling your home. Buyers often want proof that the roof meets local codes, so following these rules is important to protect your investment.
4. Enhanced Durability
A roof built to code lasts longer, saving you money by preventing the need for repairs and replacements.
5. Insurance Needs
Many insurance policies require roofs to be up to code. Non-compliant roofs can lead to denied claims or canceled policies.
How Often Are Minnesota Roofing Codes Updated?
The Minnesota roofing code is part of the broader Minnesota State Building Code, which is updated every six years. The latest update was implemented on March 31, 2020, and the next update is expected around 2026.
Considerations For Homeowners Prior To Roofing Projects
Homeowners in Minnesota should keep these factors in mind when planning a roofing project:
1. Assessing the Existing Roof
Check for damage such as leaks, missing shingles, or sagging. Depending on the condition, you might need a full replacement or just an overlay of new materials.
2. DIY vs. Professional Help
Decide whether to tackle the roofing yourself or hire a professional. Hiring a licensed contractor ensures compliance with codes and proper handling of permits and inspections.
3. Overlaying New Materials
Adding new materials over old ones can be cost-effective but might lead to issues like extra weight and ventilation problems. The code has specific guidelines for overlays, so consulting a professional is a good idea.
4. Climate Considerations
Choose roofing materials that can withstand Minnesota’s harsh weather, including heavy snow and ice, for a durable and long-lasting roof.
Also Read: What to Do if Your Roof Suffers Hail Damage in Minnesota
Ensure Your Roof Is Up To Code With The Experts At Clear Cut Xteriors
Knowing the Minnesota roofing codes is crucial for keeping your home safe and sound. By staying updated on the latest requirements, evaluating your roofing needs, and working with licensed experts, you can make sure your roofing project is done right and follows local rules.
Choose Clear Cut Xteriors for expert roofing services. Our licensed professionals ensure your project meets all building standards with high-quality workmanship. Contact us today at (651) 340-3410 to get started and see the difference!
