Cause: Moisture is probably getting underneath the paint, perhaps from a leaking gutter overhead or from a steamy bathroom on the other side of the wall.
Cure: If you catch the problem right away, you might just need to address the moisture issue and then scrape off the loose paint, prime bare spots, and repaint that wall, for a total of a few hundred to a couple thousand dollars. Delay too long and the siding might rot. Patching and repainting the whole house might cost $10,000.
To prevent a chronically steamy bathroom, consider installing a new ventilation fan with a humidity-sensing switch that automatically exhausts moisture-laden air. Cost is about $250.
2. Flickering lights
Cause: If only a single bulb flickers, it might be loose in its socket or in need of replacement. If lights always dim when the refrigerator or other appliance turns on, the circuit might be overloaded. If groups of lights flicker, connections at the electrical panel or elsewhere might be loose, causing power to arc—or jump—over the gaps. Arcing is a serious problem; it starts fires.
Cure: Anyone can tighten a bulb. Handy homeowners can shut off circuits and tighten loose connections within switch boxes. If you’re not comfortable doing that, or if you suspect an overloaded circuit or loose connection at the panel box, call in a licensed electrician. You’ll pay $150 to $250 for a new circuit, and $500 to $700 for a new electrical panel—way less than what you’d spend to recover from a fire.
3. Rustling in a wall
Cause: Sure, termites usually signal their presence by building pencil-thick mud tubes up from the ground or by swarming from pinholes in floors or walls. But did you know it’s also possible to detect them by sound? Tap on a wall and then press an ear against it. See if you hear rustling that matches recordings of Formosan or other termites. A sound like crinkling cellophane could mean carpenter ants.
Cure: Call a pest-control professional. Cost is $65 to $100 for an inspection.
4. Loud knocking
Cause: If the knocking occurs when you turn off water, you have “water hammer,” caused when fast-moving water comes to a sudden stop and there is no air chamber (a short, specially designed piece of pipe) to cushion the shock wave. If knocking occurs when your furnace switches on or off, metal ducts are expanding or contracting as temperature changes.
Cure: If water pipes are the issue and there is an air chamber near the faucet, it may be filled with water and needs to be drained. You might be able to do this yourself. If you’re not confident of tackling that or if there is no chamber, call a plumber ($65 an hour) to add one. Those snapping ducts? Just get used to them.
5. A toilet tank that refills all on its own
Cause: Worn interior parts may be causing water to trickle through the toilet constantly, causing the water level in the tank to lower and eventually triggering the refill mechanism. A leaky toilet potentially wastes 1,500 gallons a month.
Cure: Untangle or loosen the chain—it may be too tight and preventing the flapper from seating fully, letting water leak out the flush valve. Or, try bending the tube connected to the float ball. If those don’t work, replace the valve and flapper inside the toilet tank (under $25 if you do it yourself, and a little more if you upgrade to a water-saving dual-flush valve).
6. Creaks and groans
Cause: All houses creak and groan a little as parts expand and contract with temperature fluctuations and with changes in levels of humidity.
Cure: None—it’s normal for house to make a few snaps and pops. But don’t ignore really loud groans when there’s been an unusual amount of snow or rain, especially if your house has a flat roof. There may be an excessive or even dangerous amount of weight on your roof. If you suspect that may be the case, be prudent: Get everyone out of the house and call in a professional to check the roof.
7. Musty odors
Cause: Mildew, a fungus, is growing because indoor air is humid enough to allow condensation to form on cold surfaces. Basements are favorite haunts for mildew.
Cure: Keep surfaces dry by one or more strategies: increase air movement with a $20 fan, keep relative humidity below 50% in summer or 40% in winter with a $175 dehumidifier, or make surfaces warmer by adding insulation.
8. Rotten-egg smell when you run water
Cause: Bacteria that produce hydrogen sulfide gas (the scientific name for “rotten egg smell”) are in your plumbing, or there is a problem with your water heater. Fill a glass with hot water, step away from the sink, and take a whiff; if you detect no sulfur smell, they’re in the drain.
Cure: Disinfect the drain by pouring in a $1 bottle of 3% hydrogen peroxide solution, sold at drug stores. A sulfur smell in only hot water points to the water heater as the problem; call a plumber to disinfect the system or replace the tank’s magnesium anode. If hot and cold water both smell, call your water supplier (or health department if you have a well).
9. Strange-tasting tap water
Cause: Mineral content of drinking water varies, so taste does too. But if the water tastes metallic, iron or copper may be leaching from pipes. If you taste chlorine, your water supplier may have overdosed on disinfectant, or a correct level could be interacting with organic material within your plumbing system.
Cure: If chlorine seems high at all taps, or if you taste metals, call your water supplier or have your well water tested. If only one tap has water with high chlorine or if the taste goes away after you run water for a few minutes, flush your system or call a plumber.
An under-the-counter water purifier with a top-quality activated carbon filter will remove heavy metals, bacteria, and other contaminants. In addition, it removes odors and bad tastes. Expect to pay $150 to $200 for a purifier with a replaceable cartridge.
10. Sour milk
Cause: With today’s hyper-pasteurized dairy products, milk doesn’t sour easily. So if it or other refrigerated food spoils unusually fast, the temperature in your refrigerator could be too high.
Cure: Get an $8 refrigerator thermometer and adjust the control so on each shelf stays below 40 degrees. If you can’t achieve this, consider buying a new Energy Star-rated refrigerator. Fridges are pricey, $450 to $2,000 or more, but you’ll save energy as well as food and might qualify for rebates.
11. Trembling floors
Cause: If items on tables and shelve jiggle and shimmy when you walk past, or if your floor feels like it gives under your weight, the floor joists might not be sturdy enough or past remodeling might have removed a support wall.
Cure: Have a structural engineer or experienced contractor see whether you can add more joists, bolster existing ones with an additional layer of plywood subflooring, or add a post to support the floor better. You’ll pay up to $500 for a structural engineer to evaluate your problem.
12. Mysterious breezes
Cause: If a ground-floor room seems drafty, air may be seeping in along the foundation or through an improperly sealed window or door. A drafty attic can make things worse, as warm air currents will rise naturally and exit through any gaps in the attic, pulling colder air in through lower-level cracks.
Cure: Starting in the attic and working your way down, seal all gaps.