Air ducts can last a long time if they’re properly maintained. An energy audit can assess their condition.

QUESTION: I have a question regarding the air ducts on my 2,000 square-foot house built in 2007. If we have the ducts sealed now, will we still have to replace them in four years when we likely will be replacing my air conditioner?

ANSWER: It’s hard to say without knowing the condition of the ducts. If the system was designed and installed correctly, it shouldn’t need to be replaced that soon. If you feel the ducts are leaking, you probably should have an energy audit first to assess the ducts and determine the leakage volume. That audit would determine if it’s worthwhile investing in repairs or waiting until replacement of the AC unit.

Q: Why do grackle birds pinch off the leaves on my orange tree? Are they trying to get closer to the fruit? The whole top of my tree is leafless now, and I watch the birds snipping the leaves while they’re sitting inside the crown of the tree. Any suggestions?

A: Most likely they take the leaves to use in nest construction. Since grackles are often found in large groups, they could be removing quite a few leaves off the tree. There may not be much to do short of covering the top of the tree, but a pest control company might be able to help.

Q: Do you recommend using a radiant barrier-type paint on the outside of our house that supposedly can help with insulation? I was told it could be sprayed or painted on the roof and sides of the house where the sun shines intensely. Reportedly, it would then help lower our electric bill for air conditioning during the summer.

A: Unfortunately, it’s rare that homeowners see much benefit or utility savings when coatings like that are applied to houses in Arizona. But in the last 20 years, cork coatings have come on the market and have gotten lots of positive feedback. But it’s still too soon to tell how the cork will hold up and block UV rays on a long term basis under the intense desert sunshine. In the meantime, use good quality 100 percent acrylic exterior paint.

Q: How often should the fill valves be replaced under a bathroom sink? My home is 22 years old and many valves in the house are original and are showing some signs of corrosion. A plumbing company that did some work at my house said they all need replacing, but I’m not sure if that’s really true.

A: If the valves are corroded, then they should be changed, especially if they are the old-style gate valves that have to be twisted to turn off the water. You want them replaced with ¼-turn ballcock style valves that make it easier to turn off your water in an emergency. You also want to have the water supply lines replaced, too. The cost should not be too great because the parts are not that expensive.

Q: I had some stucco repaired before my house was painted, and the product used apparently had silicone in it. Now the new paint job is peeling off where the repairs were made. The paint did not adhere properly to the affected spot. How can I fix this?

A: Building supply stores can sell you a water-based primer to use on that area of your wall. After you prime the wall, you can then repaint successfully.

For more do-it-yourself tips, go to rosieonthehouse.com. An Arizona homebuilding and remodeling industry expert for 29 years, Rosie Romero is the host of the syndicated Saturday morning “Rosie on the House” radio program, heard locally from 8-11 a.m. on KNST-AM (790) in Tucson and from 9-11 a.m. on KGVY-AM (1080) and -FM (100.7) in Green Valley. Call 888-767-4348.