DIY Network

Keeping the Inside Out: The Basics From "Blueprint for Home Building" episode DBHB-110

Host Jeff Wilson discusses insulation in this week's episode of Blueprint for Home Building.

In the past two episodes you have learned about cooling and heating your new home, but now it's time to see how important insulation is in constructing your dream house. Host Jeff Wilson will cover the topic from the basics to why insulation is also a noise reducer in your home.

The term insulation refers to any material that's used to slow the transfer of heat and air, but while heat and thermal management are the most commonly known functions of insulation, there are a few others of which you need to be aware.

There's a lot to know about insulation, including the different types you can purchase and the ways to install them. But before we get started you need to know a few basics.

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	Figure A
	Figure B

The Basics

There are fundamentally three functions that you want from insulation:

1. One is thermal properties. This is the ability of the insulation to moderate the flow of heat from outside to inside or vice versa in the cooling season. In order to rate the thermal performance of insulation products, experts use what are called "R-Values" (figure A), which means everything in the home is resistant to heat loss and heat gain, which are the R values. R value is a measure of resistance of heat flow through a material. The higher the value the more resistant to heat flow the insulation will be.

   Note: The Department of Energy has recommended R values for all the different climates areas in the United States.

2. Two is how it deals with air leakage. This is where the concept of creating a building envelope (more information, below) is important. The air leakage that builders are concerned with occurs through gaps, cracks and holes around piping (figure B) and wiring. To properly insulate a home you need an air-barrier system. Typically in a home, 40 percent of the heat loss or heat gain comes from air infiltration.

3. And lastly, how does it deal with moisture management in the walls and roof assemblies. A home can get moisture in the wall from several sources. One of the most obvious, of course, is external rain. You want to put on the right amount of insulation so the moisture that's in the wall cavity won't condense. You also want a good enough barrier on the external side that the moisture or the bulk water can't get in there from the rain.

A properly insulated home that fulfills all three of the above functions can save you anywhere from 30 to 50 percent on your energy bills. For this reason, it's important to understand the three functions of insulation thoroughly.

Note: Another thing you should look for when insulating your new home is to make sure that all parts of the house are insulated.

Figure C

What Is the Building Envelope?

All of your insulation products working together will form the insulating system, or as builders sometimes call it -- the "building envelope" (figure C).

The building envelope is that area of construction that's between the inside and outside of the house. Typically it's the exterior walls, roof, basement and basement floor.

A tight and efficient building envelope will keep the heated and cooled air inside by plugging up any gaps or cracks in the building envelope.

Talk with your builder about the type of insulation or moisture barrier that will work best for your home, especially if you live in areas with heavy rainfall.

Now that you know the three basic functions of home insulation, which are to control heat, air and moisture, in the next segment you'll learn about the different types of insulation you can purchase.

GUESTS :

Anthony Grisolia
Building Performance Specialist
IBACOS, Inc.
Website: www.ibacos.com

John Holton
Senior Architect
Ibacos
Website: www.ibacos.com

Shawn Rippon
VP Marketing
Icynene
6747 Campobello Rd.
Mississauga, ON, Canada L5N 2L7
Toll-free: 800-758-7325
Phone: 905-363-4040
Fax: 905-363-0102
Website: www.icynene.com

Matt Klym
Installer
Suburban Insulation, Inc.
193 Crowe Ave.
Mars, PA 16046
Phone: 724-625-2257
Fax: 724-625-3720
E-mail: mars@installed.net
Website: www.ibpteam.com

Gale Tedhams
Insulation Products Manager
Owens Corning
3000 Hasty Rd.
Toledo, OH 43615
Phone: 419-248-8978
E-mail: gale.tedhams@owenscorning.com

Michael Buchtel
Do-it-yourselfer
Insulation Fan
105 Levinson Pass
Williamsburg, VA 23188
Phone: 757-592-0184
E-mail: va_homebyte@yahoo.com

Dan Lea
Director
Cellulose Insulation Manufacturer's Association
136 S. Keowee St.
Dayton, OH 45402
Phone: 937-222-2462
E-mail: cima@cellulose.org

Wayne Gersch
Title: Insulation Products Manager
Owens Corning
Owens Corning 1 Parkway
Phone: 419-248-6833
E-mail: wayne.gersch@owenscorning.com