Other stories by Martin Holladay

• Q&A: R-19 vs. R-20 Wall Insulation

  Q: The federal stimulus plan's energy tax credits for insulation are based on the 2009 IECC, which raises the wall insulation requirement for climate zones 5 and 6 from R-19 to R-20. To meet this requirement, the R-value of the cavity insulation must be at least 3.63 per inch. Does this mean that...

• Q&A: Is It Safe to Retrofit Exterior Foam Insulation?

  Q: I built a lot of homes in upstate New York in the 1980s using 2x6 studs, fiberglass batts, and a poly vapor retarder for the shell. Given the rising cost of heating and cooling, the owners are asking about energy upgrades to their walls. I'd like to suggest adding 1 or 2 inches of rigid foam on...

• Q&A: Does Radiant-Barrier Paint Work?

  Q: My painting subcontractor is recommending Thermo-Tek, a paint the manufacturer says is a radiant barrier. What can you tell me about products like this one or similar coatings made with something called ceramic microspheres that claim to have thermal characteristics and promise significant...

• JLC Extra Q&A: Comparing Propane and Oil

  Q. Which home heating fuel is usually cheaper, oil or propane?

• A Close Look at Common Energy Claims

  Understanding energy consumption and moisture movement in the homes we build is hard enough; rampant half-truths and misconceptions only make it harder.

• Q&A: Vapor Retarders and Building Inspectors

  Q: I'm building a house in North Carolina, which has a mixed-humid climate (climate zone 3). My local building inspector - backed up by his boss - requires a polyethylene vapor retarder on the interior side of cellulose-insulated walls. My insulation contractor says that interior polyethylene is...

• Q&A: Flash-and-Batt Insulation: Good Idea or Bad Practice

  Q: Is the flash-and-batt technique - where an inch or two of spray-foam insulation is applied to the interior side of roof or wall sheathing before fitting rafter and stud bays with fiberglass batts - a good way to insulate?

• A Builder's Guide to Energy Codes

  A close look at current energy codes - and where they're headed.

• Efficiency Dos and Don'ts From an Energy Nerd

  With high fuel prices here to stay, now is the time to get it right.

• Q&A: Are Bubble-Wrap R-Value Claims Accurate?

  Q. Are Bubble-Wrap R-Value Claims Accurate? Am I the only one confused by the claims of manufacturers of foil-covered bubble wrap and foil-covered flexible thin plastic foam? Apparently, if one is to believe the advertising, a 3/8-inch-thick roll of foil-