Rugs find their place on patios, porches

It can add just the right splash of color to a patio.

It can make a small urban terrace seem larger.

It invites guests to linger in an outdoor seating area.

Often made of a sturdy synthetic, this "it" is an indoor-outdoor rug.

In just the past few years, using rugs outdoors has become extremely popular, fueled by homeowners' desire to make their outdoor spaces feel and function like interior rooms, says Craig Jenkins-Sutton, president of Topiarius, a Chicago urban landscape design firm.

These seemingly magic carpets might enhance your outdoor spaces, but there are factors to consider about when and where they belong.

Lying out in the open?

The label may proclaim a rug suitable for the outdoors, but placement is "preferably in an area where they are protected from the elements," like a covered porch, says Los Angeles interior designer Mark Cutler.

'If you are using the rug fully exposed, then you will want to use a thinner one so it doesn't retain the moisture [after a heavy rain]," he adds.

"A thick one is fine," he adds, " but you will need to hang it to dry, otherwise you will get mold and critters on the underside."

Polypropylene is a common fabric that allows outdoor rugs to resist mildew, mold and fading from sun exposure.

A quick drying rug is also handy for cleaning because it can be easily hosed off, says Kurt Mull of Webster Carpet and Rugs, Cherry Hill, New Jersey.

Finding complimentary colors and patterns

Anyone who shopped for an outdoor rug a few years ago, but couldn't find the design they wanted, will be surprised at the choices now.

At the online home furnishing retailer Bellacor, for instance, the site features three times as many outdoor rugs this summer than last year, with similar annual increases since 2014, says spokesperson Marlon Heimerl.

Colorful, bold patterns may be more amenable outside than in, says Alisa Jaimeson of LuxeDecor, an online home furnishing site. "Some of the most prominent outdoor trends we're seeing are colorful stripes and bohemian patterns."

Still, "the rug should compliment the style of the client and should flow with the exterior design," says Sara Chiarilli, owner of Tampa, Florida, interior design firm Artful Conceptions.

If outdoor furniture is a solid color, choose a colorful, patterned rug, but "busy" furniture or cushions demand a "calming" rug, Chiarilli says.

Establishing a room-like feel

The great outdoors, even when it's just a step out onto a patio, "can feel limitless," says Chiarilli.

"A well-sized outdoor rug can help define an exterior room and transform a patio into a space that feels and operates like an interior room," explains Cutler. "Outdoor furniture has a habit of just floating around on these big decks, but using an outdoor rug correctly will break down the scale and make a giant area feel like a series of distinct spaces," he adds.

Indeed, the same thinking about placement of rugs in the interior applies to the exterior, too, Chiarilli says. A rug should be big enough, she adds, to "encompass a sitting area, coming underneath at least the front of furniture pieces."

Also, when used under a dining table, a rug should be large enough that chairs can be pulled out and in without touching onto the flooring underneath the rug.

Covering lots of territory

Maybe because they're associated with enjoyable outdoor activities like barbecues, informal gatherings and lounging, designers say indoor-outdoor rugs have a fun appeal, and they can be used to brighten just about any space that demands durable flooring.

Mudrooms, kids' rooms, laundry areas and doorway mats are popular insider uses.

Moreover, because many indoor-outdoor rugs are relatively inexpensive, buyers can "experiment" with colors and patterns, without a long-term commitment to a particular choice, says Christine Villanueva of LuxeDecor.