QUESTION: The floors of our 16-year-old townhouse are carpeted, but whenever anyone walks in the first-floor foyer or the stairs to the second floor, there are annoying squeaks. What is the cause, and what is the cure?ANSWER: Most squeaks occur when the subfloor loosens from its supporting joists and rubs against a popped nail. For stairs, the problem is similar: The tread loosens from the riser. In both cases, you can silence the squeak by eliminating the movement.If you have easy access to the floor joists in the basement, first have someone walk on the floor above to determine where the squeaks are. Then, insert a wood shim there, tightly between the subfloor and the joist. That should stop the movement - and the squeak.For the stairs, the cure is the same: insert a shim between the riser and the tread.You may not be able to get under the stairs or the floor. In your case, you're going to have to pull up the carpet to get to the floor underneath. Locate the squeaks in the same way, and then renail the subfloor to the joist. This time, use ringed nails, which have edges that lock into the flooring and are designed to prevent loosening, or spiral nails that turn like a screw and tighten when driven in. If you can work from the top down, drill pilot holes before you nail, so you won't split the wood.

QUESTION: Should I use 87-octane gasoline or a higher octane in a lawn mower?ANSWER: Follow the mower manufacturer's recommendations, if you know them. But in general 87 octane, the lowest grade of gasoline typically available at the pump (known as "regular unleaded") is just fine. Small engines typically don't need expensive gasoline and a rating of 87 is the least expensive grade.But always make sure the gasoline in the mower engine is fresh, meaning no more than a month old. As gas ages, it tends to lose some of its punch, and it may be harder to start the engine and keep it running because of that. At the end of every season, empty the mower engine.

QUESTION: We have a double oven that works great, but it's harvest gold. Can it be repainted?ANSWER: Yes, but I strongly recommend hiring a professional who specializes in refinishing appliances because ovens generate heat and so the new finish must be heat-resistant.Instead of repainting, which may be less durable in the long run, you might want to ask about porcelain enameling, which manufacturers use on range tops, oven doors, burners, and grates because it is less susceptible to scratching and staining.In any event, contact the manufacturer of your oven - most large appliance companies have the documentation on their products, even those made several decades ago - to make sure the oven can be repainted; the company may have used some sort of finishing process on the appliance that will make it difficult to do so.If you decide to use a professional refinisher, make sure the estimate spells out how long the new finish is likely to last; get a written guarantee of the work.