They suck up everything from chunks of plaster and nails to microscopic drywall dust and pools of water.
The mess that comes with drilling, sawing, sanding, and demolishing can be formidable—consisting of debris that's at once too rough, too large, and too fine for the average household vacuum cleaner. The answer is stored in millions of garages and basement workshops: wet/dry vacuums. The fat hose, strong motor, and big tank of a good vac suck up everything from chunks of plaster and nails to microscopic drywall dust and pools of water. Some even have detachable motors that can be used as leaf blowers.
Wet/dry vacs range in size and power from hand-carried 1-gallon models to heavy 20-gallon monsters. A small portable or rolling vacuum is fine for the occasional minor job (and makes a great car vacuum as well), but anyone getting into a large renovation project should consider investing in (or renting) a bigger machine.
Hose diameters vary from model to model; the manufacturer matches the size to power and capacity. You will have some choice on hose length. A longer hose is more convenient, but length reduces suction.
Where the hose attaches to the tank, look for a screw-on or locking connection so it doesn't pull loose when you tug on the vacuum.
Since wood dust is a carcinogen, choose a vac that comes with a HEPA filter, which can trap particles smaller than 1 micron. (Or buy one to fit your vacuum for $25 to $70.) Look for models with a filter bag inside the tank, so you don't end up with a mushroom cloud of dust when you empty the tank.
Some models work as a pump, which lets you hook up a garden hose to clear out a flood.
Watch out for a short power cord, which forces you to drag around your own heavy-duty extension cord. Look for a built-in cord reel for long cords.
Most vacs include a floor sweep, crevice tool, car upholstery tool, and a wide water blade. Make sure the tools can be stored on-board so you have what you need where you need it.
Shop vacs make a lot of noise: 85 decibels and up is typical of unmuffled units, 60 db for those with mufflers. Decibel levels above 80 require ear protection. (Always wear ear protection when the vac is connected to a power tool.) An add-on muffler (about $10) quiets most vacs to acceptable levels.
An internal switch should automatically shut off the vac when the tank is full.
Bigger might seem better, until you have to empty it when it's full of water. A 10- or 12-gallon capacity is the most practical for household use. Plastic is lighter and cheaper than stainless steel, but steel is more durable. Tall vacs can tip easily. Low units are more stable, but this limits capacity. Try pulling the vac by the hose — if it tips, don't buy it.
Saves the trouble of grappling with a water-filled tank to empty it.
Four wheels are better than three, and at least the front two should swivel. Outrigger wheels improve stability but require a wider path and are more likely to get tangled.
Manufacturers rate vac power by many measurements, each of which means something different.
Power draw in amperes. More is better, up to 12 amps; more than that can trip a typical household circuit.
Peak horsepower. Measures maximum power. Not a good indicator of performance, but sometimes the only spec available. Look for 1.5 to 2 hp on small machines; at least 3.5 on larger ones.
Sealed suction or sealed pressure in inches of water lift. Measures the motor's suction power with no air flow. Look for 50 inches or more.
Air flow in cubic feet per minute (cfm). Tells how powerfully the motor draws in air, and factors in restrictions like filters and bags. Best comparison between similar machines. Anything less than 90 cfm isn't very effective.
Air watts, which combines air flow with sealed suction. Useful for comparing two similarly configured machines; 250 air watts and up is good.
Hooking Up Power Tools
Many power tools come with exhaust ports for attaching a vac hose to directly suck away dust or wood chips. However, unless your power tools and vac are made by the same manufacturer, you'll probably need a universal adapter (less than $10) or a roll of duct tape to connect the hose.
Better still is a vacuum that has an outlet for plugging in the tool. The outlet is wired with a delay switch so the vac starts up when you turn on the tool and stays on for several seconds after you turn it off, to clear the hose and tool.
Uses: Cleaning up small jobs, such as patching drywall, sanding wood, or clearing out a dryer duct.
Capacity: 1 to 4 gallons.
Features: Small, easy-to-tote tank with handle. Some are cordless, with batteries from 12 to 18 volts. Cordless handhelds without a hose are not very powerful; those with a hose are 1 to 2 peak hp.
Expect to Pay: $30 to $100, plus another $80 for a battery for some cordless models.
Shown: DeWalt cordless or corded wet/dry 2-gallon vac; about $100; homedepot.com
Uses: Quick, permanent access in a garage or workshop without set-up time or storage issues.
Capacity: 3.5 to 5 gallons
Features: 3 to 4.5 peak hp. All the hoses on hanging vacs are 18 feet, so if your workspace is bigger, you'll need an extension (though this reduces suction).
Expect to Pay: $70 to $90.
Shown: Shop-Vac Hangup Pro; about $85; acehardware.com
Uses: Collecting dust and debris made by power tools; small-project and car cleanup.
Capacity: 5 to 12 gallons.
Features: Power-tool outlet with delay switch; fine-dust filtration even without HEPA filter; air flow over 110 cfm and noise level less than 60 decibels, both important with power tools. Best type of all-around vac, though somewhat pricey.
Expect to Pay: $100 to $300.
Shown: Porter-Cable 10-gallon wet/dry vac; about $280; amazon.com
Uses: Demolition and construction site cleanup.
Capacity: Up to 20 gallons.
Features: Tough but weighty stainless steel tank on a rolling cart; 80-plus inches of water lift.
Expect to Pay: $225 and up for smaller models, at least $400 for 12 gallons or more; $25 to $45 a day to rent.
Similar to shown: Tornado 15-gallon wet/dry vac; about $550; sears.com
Uses: Workshop and job-site cleanup, plumbing or aquarium disasters.
Capacity: 10 to 16 gallons.
Features: Vacuum that converts to a pump (drains via a garden hose). Power increases with tank size: 3.5 peak hp for 10- to 12-gallon tanks; 5.5 hp for 14 gallons; 6.5 hp for 16 gallons.
Expect to Pay: $110 to $140.
Shown: Craftsman 16-gallon wet/dry vac; about $120; sears.com