Anyone who lives in drafty old houses knows that improving our home’s energy efficiency not only reduces your heating and cooling bills, but also improves the comfort of your home. Many increase their home’s efficiency through windows, attics and even shingles and floors. Many often overlook exterior walls when considering increasing their home’s efficiency. Yet, walls account for sometimes more than 35% of a home’s heat loss. This may be more if the walls are uninsulated. Improving your home’s efficiency through siding and insulation is important. We lose more heat through our walls than the roof, or windows. This is especially important in older homes where ceilings leak and less insulation has been blown into walls. Today we will discuss two tips to add energy efficiency when updating the siding on your home.
What Causes Heat Loss
The loss of heat through our walls is called conduction. Heat moves through solid materials such as concrete more quickly than gas materials. For example, an improperly insulated attic melts the snow unevenly where heat leaks through most easily. This exposes where the wood joists connect to the roof. Because of this, it is important for effective insulation to have lots of air. The studs are our home’s most vulnerable areas to heat loss. Usually, nearly 25% of most homes include these stud areas. While wall insulation improves the efficiency of our home, much heat still escapes through wood framing. This problem is called thermal bridging.
Improving Your Home’s Efficiency by Insulating the Home’s Exterior
The effectiveness of your home’s insulation depends on the material you currently have on the outside of your home as well as the insulation you have inside the walls. Different types of exterior materials carry different R-values (insulation values). Wood shingles provide an R-value of 0.87. Aluminum or vinyl siding yields an R-value of 0.61. Fiber cement siding only measures a 0.37 R-value. Energy code requirements for building in Idaho and similar climate zones call for above ground walls to have a combination of insulation adding up to R-20. This is higher than what is required in the basement or crawl space of your home. Improving insulation in existing buildings greatly improve their efficiency.
Because our homes more readily lose heat through the wood framing, the best options to increase energy efficiency comes from products that not only insulate the space between the walls but also the framing. Currently, there are two basic options in the market: flat rigid foam insulation and insulated vinyl siding
Flat Rigid Foam Insulation
Most people are familiar with batt and spray insulation which are great for interior spaces. However, these cannot be added to the exterior of a home. You can improve insulation by wrapping your house with flat rigid foam insulation. These sheets cover the entire exterior of the home. To increase efficiency, install two layers with the second layer covering the joints of the first. This type of insulation covers the areas prone to thermal bridging. Flat rigid foam insulation also levels out inconsistencies in the walls. This creates a flat surface making siding more consistent. The three different types of flat rigid foam most commonly used include: expanded polystyrene (EPS), extruded polystyrene (XPS), and graphite polystyrene (GPS). These types of insulation typically give an R-value of 3.8, to as high as 5.5 per inch. To learn more about these types of insulation click here.
Insulated Siding
You can also install insulated siding to increase insulation around your home. Like flat rigid foam insulation, this option also addresses thermal bridging. Insulated siding adds the foam directly to the back of the siding. Insulated siding comes in several options, including: steel, aluminum and fiber cement. Vinyl is the most popular option. Besides its insulating value, one of the greatest advantages is increased durability. The excess insulation reinforces the siding handling impact from elements such as baseballs and hail beautifully. This keeps siding nice and new for much longer than non-insulated siding. Some claim insulated siding lasts up to 100 years. Insulated siding adds an R-value between 2 to 4. However, many widely debate whether insulated siding inhibits drainage within the cavity between the siding and the house. This could increase moisture problems with rot and mold. Insulated siding is also very expensive, increasing costs between 20% to 50%. For some, this excessive cost makes the product not worth it.
By using insulated siding, flat rigid foam insulation or a combination of the two, you will be able to reduce the flow of heat loss in your home and save money. Improving your home’s efficiency through siding and insulation will decrease the costs to heat and cool your house. You will quickly see the benefits by installing proper insulation around your home. To know which system is better for you, reach out to a professional today. Whichever way you choose Specialty Home Products can help walk you through your available options. We will make sure the insulation is installed properly for the most efficient home possible. Contact our siding department today to learn more about our historic siding options.