Each year, thousands of Arizona residents email or call Romero’s radio show with questions about everything from preventing fires in their chimneys to getting rid of tree roots in their sewer systems. His goal is to provide answers that suit the specific lifestyle wherever someone lives in Arizona. Here are questions about home maintenance and improvement from the Tucson area.

QUESTION: Back in my childhood, we had a small solar water heater on top of our house. It was shaped like an old breadbox, and the water that heated up in the box ran down into the hot water pipes in the house. They used to manufacture these devices in Tucson. Whatever happened to them?

ANSWER: Those bread-box-style passive water heaters are no longer available. But you can buy some newer versions of passive solar heaters. There is one on the market that is about 3 feet by 8 feet and can be installed on your roof. A pump moves cold water through a pipe up to the device. Another pipe takes the heated water down into your water heater. Your natural gas or electric water heater can serve as your backup on cloudy days when your passive water heater can’t produce much hot water or when you need extra hot water. A passive system like this can produce about 40 gallons of water at a time.

Typically, if this hot water system is installed on your roof, it needs to face south at about a 40-degree angle. If you have a flat roof, the collector can be placed in the middle of the roof, so that neighboring homeowners won’t see it. Passive systems can be very reliable and long-lasting. A system like this will weigh about 600 pounds when filled with water, so the city and county building regulations require the installer to make sure the weight is properly distributed on your roof.

Modern active solar water heaters are more expensive and complicated. Generally, they circulate a heat-transfer fluid through a rooftop collector and then into a heat exchanger, where water for your home gets heated.

Q: I’m having a problem with a dwarf Valencia orange that I planted three years ago in my yard. It bloomed like crazy the first two years, but it hasn’t bloomed since, and it hasn’t ever had fruit. Now a couple of strange branches have grown very tall and have tiny little leaves on them. What’s the matter with this plant?

A: Generally, with a citrus tree you can’t expect much fruit at all for the first two or three years. You also have to remember that we’ve had two frosty winters in a row, and your plant may have lost a lot of branches as a result. I’d give it one more year; if it doesn’t recover by then, you should probably give up on it.

It’s always hard to grow citrus in Central and Southern Arizona because of the frost in winter; some parts of Tucson can be colder than others. Plants have to be thoroughly covered at night many times during the winter. It’s sometimes easier to grow dwarf citrus in a pot on your patio where it gets more protection from the cold. Those long crazy branches you’re talking about are probably suckers from the rootstock on which a nursery grafted the Valencia tree. You need to prune them off so they don’t take over the tree.

Q: My mother in-law has a trailer with a ramp that leads to her front door. The walkway on the ramp is made of expanded metal. It can get very slippery when wet, so I would like a way to make it less slick so she won’t fall. I need to do it inexpensively. I was thinking about attaching »-inch plywood to the metal and then coating it with some rough paint that is for non-slip purposes. Do you have a suggestion?

A: The solution you have in mind is probably the least costly remedy to the problem you face. Just make sure that you use a marine-grade plywood so that it will stand up to rain and other weather conditions. Secure the plywood firmly to the expanded metal and use a coarse enough deck paint to ensure adequate traction when someone is walking on the ramp. There are additives that you can put into paint to create a rough surface and prevent slips on walkways. Do not use paint that was intended for painting the interior of a house.

For more tips, go to rosieonthehouse.com. An Arizona home building and remodeling industry expert for 25 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) and -FM (97.1) in Tucson and KGVY-AM (1080) and -FM (100.7) in Green Valley. Call 1-888-767-4348.