Attic Insulation FAQs

Your ducts and air handler often sit in the attic. The hotter it gets up there, the harder your AC works to cool the air before it reaches your rooms, and the more heat soaks through the ceiling.

Insulation slows the movement of heat. In summer it keeps attic heat from moving down into your home. In winter it keeps heat inside.

R-value measures how well a material resists heat flow. The higher the number, the better it insulates. R-value depends on both the material and its depth.

The Houston area is in climate zone 2. ENERGY STAR recommends R49 for an uninsulated attic in zone 2, or adding up to R38 if you already have 3 to 4 inches. Depending on the material, that's roughly 10 to 15 inches of insulation.

Blown-in fiberglass and cellulose cover attic floors evenly and fill gaps around framing. Batts work in open, easy-to-reach areas. Spray foam seals and insulates at once but costs more. The right choice depends on your attic and budget.

If the old insulation is dry and clean, adding a layer on top is usually fine. Remove and replace it when it's been wet from a leak or flood, has mold, or has been contaminated by rodents.

Vermiculite insulation looks like pebbly, gray-brown or gold granules. Some of it contains asbestos. Don't disturb it. Have it tested, and follow EPA guidance if it needs to be removed.

Moisture from leaks, bathroom fans that vent into the attic, or poor ventilation lowers insulation's R-value and can lead to mold and wood rot.

A radiant barrier is a reflective foil installed high in the attic. It reflects the sun's heat back out instead of letting it soak into the attic. The U.S. Department of Energy says some studies show savings of 5% to 10% on cooling costs in warm, sunny climates.

Passive ventilation uses soffit and attic vents to let hot air escape on its own. Active ventilation adds a powered or solar fan to move air faster. Either one needs enough intake at the soffits to work.

In most homes, yes. ENERGY STAR estimates homeowners save an average of 15% on heating and cooling costs, or 11% on total energy costs, by sealing air leaks and adding insulation.

Yes. We've weatherized homes for BakerRipley and the Houston-Galveston Area Council since 2007, and we offer the same insulation and air sealing work to homeowners.