OSB Board/Wall sheathing
A 4 layer system is designed to maximize energy efficiency potential in your home. It primarily refers to the components used in a siding system. The very first component is wall sheathing, the next is the insulation material or fanfold. Proceeding the insulation is the house wrap; lastly, the last component in the 4 layer system is the insulated siding.
Energy Efficiency: 4 Layer System
Considering R-Values
In any insulating products, an R-value is assigned to evaluate an insulating material's thermal resistance. The higher the R-value, the greater the insulating effectiveness is. The type of thickness, insulation, product location, and density are all factors that determine the R-value. Additionally, the type of climate and heating and cooling system you have can also influence the R-value. Due to the variety of factors that can influence R-values, there is no one-size fits-all R-value.
To get an idea of what R-values may be appropriate for your area, see ENERGY STAR's recommended R-values map. You can also contact an insulation professional to more accurately and easily determine what R-values are appropriate for your needs.
Other benefits of insulated siding
In addition to increasing energy efficiency, insulated siding also reduces noise pollution of up to 45% from exterior sources, making your home a quieter place. Moreover, depending on the manufacturer, insulated siding can be stronger, more resistant to cracks, and impacts from objects, and have a longer lasting appeal. For example, the manufacturer, Certainteed uses Cedarboards: for an authentic look and texture of natural wood; rigid foam technology designed and tested to withstand hurricane winds; PermaColor technology to assure color performance, resistance, and durability; heavy-duty thickness for improved durability; a straight-profile face for a flat even face replicating the look of milled cedar; and lastly a lifetime limited warranty
We mentioned how vinyl siding is a type of material that is versatile, cost effective, and provides protection from weather. Though a good choice to make when choosing a siding, there can be further improvement to the energy efficiency in your home by installing insulated siding and considering which siding underlayment you have.
Energy Efficiency | Siding
What is insulated siding?
Insulated siding is like any other traditional siding with the exception of one difference. Whereas most common siding leaves an empty gap between the wall of your home and the siding material, insulated sidings fills in this gap with an insulation that is attached to backside of the siding itself.
How does insulated siding improve energy efficiency?
The space between your exterior wall and interior home is typically insulated with a batt insulation (pink insulation). Other than the physical wall surrounding your home, batt insulation is meant to repel any weather conditions outside. However, batt insulation can wear off over time, and it alone is not sufficient enough to combat extreme climates. In such harsher conditions heat or cold can seep through the batt insulation in your wall cavity and transfer through the wood studs in your wall allowing energy to leak through your walls, this is known as thermal bridging.
Insulated siding acts like an "extra blanket' around your home. It reduces thermal bridging by implementing a rigid insulated foam that contours the siding it's attached to and minimize any space between the exterior wall and siding while maximizing energy efficiency in helping homes stay cooler in the summer and warmer in the winter.
Thermal bridging without insulated siding. Photo courtesy of Progressive foam.
Thermal bridging with insulated siding. Photo courtesy of Progressive foam.
What is Siding Underlayment?
Is a material that is attached to the exterior walls of your home before installing any siding. It's primary function it to be a protective barrier against moisture and air that can get through siding or any other small openings. If there is inadequate insulation from exterior weather elements, moisture and air infiltration will travel through the wall cavities and may cause rot, mold, and energy loss. Siding underlayment helps prevent energy loss and moisture build-up when insulated siding is not being used or there is no other insulating protection covering the walls of your home.
Choosing the right siding underlayment
Siding underlayment's main purpose is to prevent moisture and air going through the wall siding. The underlayment is not limited to vinyl or fiber cement siding. It can be applied beneath any other siding textures which include brick, stone, wood, and more. It is important to choose a manufacturer that produces siding underlayment that has superior functionality in resisting moisture and air. For example, GreenGuard uses polystyrene (XPS) underlayment, which is a synthetic material that is lightweight, durable, lays flat for a smooth even finish, cuts easily for installation, and improves energy efficiency overall.
Siding underlayment
(fan-fold)
Fiber cement siding
Using Housewrap
Housewrap is similar siding underlayment in keeping air and water out, but it also uses a unique material science to allow water vapor to escape and prevent rot and mold inside the walls. There are some house wrap materials to choose from: Perforated wraps which use "micro-perforations" or thousands of holes for breathability; and Low Perm Microporous Film Wraps which use a fabric backside that is laminated with a delicate film. Tyvek® HomeWrap® is the original home wrap and is the most trusted brand in the industry. Other house wrap materials and/or brands are not as durable and are more vulnerable to water penetration and retain excess moisture
Tyvek® HomeWrap® keeps homes cool in the summer and warm in the winter. The allowance of moisture vapor to pass through helps promote drying in wall systems which lowers the risk of mold and water damage. This simultaneously happens while the house wrap stops air movement through walls further increasing the R-value to provide more energy efficiency by allowing the HVAC system to work better.
How Housewrap saves energy
Wall Sheathing/OSB Board
This is the structural bare wall without any insulation components. If too much moisture gets through walls, there is a high chance of mold and rot rendering these walls weaker. Too much air significantly decreases energy efficiency
Insulation Board
Also known as siding underlayment. It is the last line of defense against energy loss. It prevents moisture and air penetration
Tyvek Housewrap
2nd line of defense - Housewrap allows moisture vapor to pass through to enhance drying of wall systems while stopping other air movement and excess moisture
Insulated Siding
This is your first line of defense when it comes to energy efficiency. Rigid foam is attached to the back-end of the siding to increase insulation value while still promoting a smooth flat finish