Insulation & What You Need To Know

Look closely at the roof of this picture. Notice how there is white on the roof above the garage and not over the house? Know why? Heat loss!! This time of year is great for understanding how well, or not, your house is insulated. First thing in the morning, after a frost and before the sun has a chance to melt it off your roof, take a look to see if you have areas that heat is escaping. If you have tree limbs over your roof then those areas don't count. But, if your roof looks similar to the pictured one, you should have it inspected by a reputable insulation company. So let's discuss some insulation specifics.

Purpose of insulation

There is some misperception out there that insulation is to assist with air loss. Stuffing insulation in openings will not arrive at the desired result. Insulation, including spray foam, will still allow air to flow through it and negate a good portion of the insulation in the first place. For best results, it is imperative that all gaps and penetrations be sealed prior to installing insulation.

Poly Seal

Poly seal is a spray form of insulation that comes in a can with a directional tube to allow you to get between anything that penetrates the wall and the wall itself. This will close off-air and even pests from entering your house and attic. Poly seal is not to fill in major gaps. Fiber cement board and siding should cover the bulk of the openings and poly seal will close up the fine areas.

Once your "envelope" is sealed up and you are ready to insulate what type goes where?

Walls

Standard 2x4 walls are usually insulated with fiberglass batt insulation or foam. Batt insulation comes in different densities that range in rating from R11 to R15 with R13 being the minimum to meet Texas code. Spray foam will get you a rating between R14 and R28, depending on the product used. Keep in mind that installing fiberglass batt yourself can be a terrible job, depending on how much you have to install.

Be sure to cover your body from head to toe to avoid the insulation touching your skin.

When installing wall batt insulation it is best to use faced insulation which means it has a paper cover on one side. Install with the paper side facing the room and to ensure the insulation stays in place, you can staple it to the studs.

Floors

Second story flooring requires a minimum of R30 to meet Texas Code.

Attic

When using fiberglass batt insulation in your attic, a minimum value of R38 is required in Texas. More common in an attic is blown cellulose insulation which, to meet code, must be a minimum of 12" thick.

Radiant Barrier

Installing radiant barrier in your attic can decrease your heating and cooling costs by as much as 45%, depending on the balance of your home’s envelope. Radiant barrier installs across your attic rafters and keeps heat and cold from permeating your attic and ultimately your home.

Energy Audit

A great way to find out where your home is lacking is to hire a home energy audit company to asses your home. There are companies that specialize in this process. Another option would be to use one of the larger insulation installation companies to give you advice on what your home needs to be the most energy-efficient.