Drainage Planes

Key to replacing the exterior of your home is making sure you have a proper drainage plane. When you've removed all of the old siding, take advantage of this time to add additional insulation, replace any rotting sheathing, and improve air sealing. These items will help prevent water damage and provide an air-tight home. Learn more

Also remember that this is one piece of the house-as-a-system approach, and interacts with insulation, air sealing and moisture management.

Exterior Finishes

If you're going to replace the exterior of your home, complete a simple life cycle analysis that includes sustainability when choosing between finish products. Take into account the environmental impact of harvesting and manufacturing the siding, where it is made, the transportation impact of getting it to your home, the durability and performance of the product, the maintenance requirements, the impact of disposal when it comes time to replace it, and cost both initially and over the lifetime of the product. The initial investment of certain products may be higher than others but may be a less expensive over its lifetime and a better choice.

Each product has both favorable and unfavorable sustainable attributes. To highlight some of the defining qualities among the options, fiber cement board balances lifetime performance, maintenance, durability, cost, and manufacturing. Wood siding has a very low embodied energy and, depending on harvesting methods, the lowest environmental impact. Brick and steel are very long lasting but use the largest amounts of energy to manufacture which releases carbon dioxide and air pollutants. Vinyl is a poor environmental choice in nearly all these ways. With proper maintenance, most cladding products can last the life of the building. Look for exterior finishes that can withstand our harsh Minnesota climate, that are sourced locally from sustainable resources, and contain recycled content.

View exterior finish comparison chart

Click on finish options below for additional information about siding characteristics and compares performance factors:

• Fiber Cement Board
• Wood
• Metal siding products
• Stucco
• Brick
• Stone
• Engineered wood
• Vinyl

Roofing

Like siding, the roof of your home should be durable, functional, and aesthetically pleasing while still being sustainable. The materials used on your roof provide moisture resistance that greatly impacts the energy performance of your home. The roof is the first line of defense against rain, and the same drainage plane principles that apply to siding apply to roofing. In addition, you need an ice and water shield on bottom edge of roof and in valleys.

Roof penetrations must be sealed and flashed to prevent damage to your roof material and leaks. If moisture resistance of your roofing material fails, it could jeopardize the performance of your attic and even wall insulation and damage both framing and finishing materials. The same is true for the the insulation in your attic or roof space; if improperly insulated, winter ice dams can form and damage roof materials. (Learn more about resolving ice dam problems.) Proper installation of roof materials is vital to its performance. Many manufactures require product- specific certified installers to maintain warranties. For those that do not, make sure you select a reputable, experienced installer. Your roof is an integral part of your building envelope!

roof materials comparison chart

Since re-roofing is typically done out of necessity alone, most products are selected based on initial cost, rather than considering cost per year of useful life. As a general recommendation, products that offer longer lifetime performance are more desirable. The high embodied energy and cost of more durable products may be recouped by less frequent replacement. Metal roofing products are a good option in terms of cost, durability, lifetime performance, and recyclability. From manufacturing to disposal, asphalt shingles are a poorer choice in terms of environmental impacts. If you collect rainwater for landscaping, be aware that your material choice may affect the safety of using that water on food crops. Learn more here, and compare impacts in this chart. The information below describes roof products with respect to performance and sustainability. More info can be found in the Minnesota Sustainable Housing Initiative.

Types of roof materials:

• Metal (lead-free) Roof products
• Wood Shakes & Shingles
• Clay Tile
• Fiber Cement Shingles
• Composite recycled rubber & plastic shingles/tiles
• Asphalt shingles
  

Other roofing options:

• Solar integrated roofing systems
• Green Roofs
  

Cold Roofs:
As part of your building envelope, your roof and unconditioned attic space should be detailed as a "cold roof." In cold climate areas, this means that the attic space should vented to move "cold air above the insulation but below the roof materials." Natural ventilation prevents the build up of ice dams and helps regulate roof temperature. Avoid mechanical roof ventilation systems as they often lead to moisture issues. Ventilation at roof peak allows warming attic air to escape and soffit vents draw cool outside air into you unconditioned attic space to reduce ice damming.

Ice dams are a common problem to many Midwest homeowners. Ice dams occur when snow melts from heat escaping through the roof, and ice builds up on the edge of your roof preventing melted ice from draining off. Learn more

Roof penetrations including skylights, ventilation ducts, and chimneys that are uninsulated or improperly sealed can lead to energy loss, ice dams, and roof deterioration. It's important to have proper flashing and insulation around any roof penetration to avoid both air and water leakage. Learn more