(MONEY Magazine) – Just when you thought the housing boom couldn't send renovation prices much higher, Hurricane Katrina blew them through the roof. Now manufacturers and retailers are hustling to help Gulf Coast residents start replacing or repairing some 632,000 destroyed or damaged homes. Plywood prices were up 50% in some areas in the weeks after the storm. Cement shortages have plagued at least 32 states. Rising gas prices mean that trucking even small loads is suddenly costlier. What to do for your home redo? Delaying some projects until prices drop might make sense. Or consider substitute materials and building methods to help ease wallet squeeze.

WOOD, IF YOU COULD

WHOLESALE LUMBER +14% Since Katrina hit on Aug. 29

Plywood is extremely strong and versatile. It's also expensive lately, selling for $28 per four-foot-by-eight-foot sheet in September. • One alternative to plywood for floors: oriented strand board (OSB). The price is up too, but it's still 20% cheaper than plywood, and contractors say the newest generation of OSB is plenty strong enough. • For exterior walls, think about skipping both OSB and plywood and trying foam sheathing instead. That's right, foam. "I don't mean the Styrofoam that was in your McDonald's cup in 1976, which was lots of little Styrofoam balls pressed together," says Jonathan Brown, a general contractor in Chicago. "This is extruded foam that comes out in one stronger sheet." It's one-third to two-thirds the price of plywood, depending on foam thickness. Plywood is still stronger, so your builder must compensate by bracing the walls. But even with the bracing, foam sheathing should still cost less in many parts of the U.S. • To save on lumber, you could use what are called advanced framing techniques. Example: Spacing studs 24 inches apart instead of the usual 16 requires less wood for your walls. When done properly, it's a safe move that saws costs and saves heat, says Shawn Martin, director of applied technology for the National Association of Home Builders Research Center. "Every time you have a stud in the wall," he says, "that's a place where there's no insulation. You want enough studs in a wall to make it strong enough, but don't go beyond that."

PIPE DOWN

COPPER PIPE AND TUBING +15% In the past 12 months

A new bathroom, kitchen or laundry room should be located as close as possible to other "water rooms" in the house (or be stacked vertically if they're on separate floors), and any hot-water heater should be positioned nearby. Tightening everything up saves on piping materials like copper or polyvinyl chloride (PVC). Plus, hot water arrives at the tap faster, meaning less water gets wasted. Families in houses designed this way use 38 gallons of hot water a day, compared with an average of 64 gallons nationally, researchers at Oak Ridge National Laboratory report. • If you must spend money on a lot of piping, look into cross-linked polyethylene pipe, or Pex. Every twist and turn of copper pipe requires a separate joint that must be soldered by someone charging an hourly rate. Pex is plastic and flexible, so it's possible to quickly "fish" the pipe through your walls as one continuous tube (and leave fewer points where the material can spring a leak). Plus, it's cheap--about 39¢ a foot for inch-wide pipe.

CONCRETE RESULTS

CEMENT +13% In the past 12 months

New Orleans in drier days had been the port for 10% of the nation's cement. Since many areas of the renovation-mad U.S. were already seeing tight supplies before Katrina, don't expect an easy time getting your orders filled in the next year or so. This is especially a problem if you're building a house--or an addition, or a garage--with a traditional foundation. Conventional construction typically means sinking the footing (the concrete that supports the house) below the soil's frost line so that a cold snap won't crack the foundation. Some experts recommend a frost-protected shallow foundation (FPSF), which has insulation around the foundation to contain heat. In some areas, an FPSF can trim up to 21% from your tab because the footing needn't reach down as far; it uses as little as a third of the concrete (less concrete means less cement), and you'll save on labor costs for excavation.

A BAD CASE OF SHINGLES

ROOF SHINGLES +10% In August alone

Post-storm demand is fierce for quick-repair goods like roofing and plywood. Some prices may stay sky-high for six months. "If something can be postponed, it might not be a bad idea," suggests NAHB economist Michael Carliner, who expects materials costs to rise 10% to 12% in the next year--maybe more in the Texas-through-North Carolina belt. • Don't count on most prices dropping to pre-storm levels over the next year or two. Victims of last year's Florida hurricanes are just now starting to rebuild. Katrina's casualties, unfortunately, should need an even wider recovery window.