When Repairing a Roof, Do I Have to Meet the New Codes?

New Code Threshold

• Some states and counties require roof repairs to comply with new building codes only when they constitute a significant portion of the roof. For example, Minnesota's state building code specifies that when a repaired area is at least 25 percent of a roof's total square footage, the repaired area must meet all current building codes. However, the remaining portion of the roof only needs to comply with codes that were on the books when it was installed. Full replacement roofs always need to comply with new codes.

Relevant Code Provisions

• Building codes include several different specific requirements that may apply to roof repairs. These include structural codes that relate to trusses, rafters and the load-bearing capacity of a roof's structure. Other codes deal with roofing materials, such as those that require shingles that do not contain asbestos or are resistant to damage from hail. Other codes that roof repairs must comply with cover the addition of a second roof layer or the addition of a new, heavier roofing material, such as slate.

Variations Among Codes

• Before undertaking a roof repair, it's essential that you understand which codes apply to you. Local building codes are the most specific, incorporating elements from state codes, national residential codes and international standards. You may need to refer to these other codes to determine exactly what your roof repair needs to be in compliance with. It's also possible that codes for roof repairs haven't changes since your home was built or since a new roof was installed, which leaves you free to make repairs, using the materials and methods that the rest of the roof uses.

Working With a Contractor

• All but the simplest roof repairs will require you to hire a contractor with professional roofing experience. When comparing roofers, ask about their knowledge of local building codes. The estimated price of repairs based on your existing roof may be too low when a roofer needs to buy different materials to comply with new codes. Likewise, if a roofer doesn't include the time it takes to receive a building permit when one is required, the process can throw off your home repair schedule and delay your project.