All about plywood

Installing panels to protect your home's windows requires some up-front preparation and thought.

Published April 17, 2005

If you choose plywood to protect your windows, here's how to attach it properly.

First, the Florida Building Code recommends a minimum thickness of 7/16-inch, exterior-grade plywood.

The Federal Alliance for Safe Homes recommends double-headed nails, wood screws, bolts, wood or masonry anchors, nuts and large washers. The type of fastener required will depend on the type of construction (wood, masonry or concrete) and the type of exterior veneer (siding, brick or stucco).

If your home is masonry, "we recommend you use at least 21/2-inch masonry screws," said Leslie Chapman-Henderson, president of the alliance. "We do not recommend masonry nails."

Some of those masonry screws come with sleeves; some don't. Use them if you've got them. The alliance also recommends using washers with the screws.

If your home is wood, the alliance recomments using 10-penny common nails, 12-penny box nails, or 21/2-inch wood screws.

Wendy Fontaine, a spokeswoman for the Institute for Business and Home Safety in Tampa, says you can leave wood screws in place in a wood home. If you used nails or you don't want to leave screws in place, a two-part epoxylike putty filler is available in the paint sections of home improvement and hardware stores. Knead the two parts together and plug the holes. The plug will harden, and next time around you can redrill your hole there.

How many fasteners do you need?

The alliance offers this guideline:

"If the shortest dimension of the window or door is 4 feet or less, space fasteners at 6 inches on center. If the shortest dimension of the window or door is more than 4 feet and less than or equal to 6 feet, space fasteners at 4 inches on center. Plywood should not be used where the shortest dimension of the window or door exceeds 8 feet."

When you take down plywood, remove the fasteners and patch the holes with stucco, grout patching or wood putty, depending on the exterior of your home, the alliance recommends. Then touch up the paint.

Some people install their plywood on masonry homes with a permanent anchor, epoxying a sleeve in place and then attaching the plywood with a permanent bolt or screw. If that's what you did, just leave it in place. (Your fasteners should be rated for 490 pounds pullout strength. The label will tell you this.)

If you used masonry screws (one popular brand is Tapcons), you can back them out, remove the plywood and reinstall the screws. If you don't like the blue color of Tapcons, you can paint them to match your house.

Tapcons can be reused as long as they get a good bite into the concrete, said Jeff Burton, building codes manager for IBHS.

Citing information from the technical department of Concrete Fastening Systems, maker of Tapcons, Burton offered this guidance:

Remove the Tapcon to take down the plywood, then hand-tighten the Tapcon to seal the hole. This will also protect the threads on the screw.

When next you batten down, remove the screw, replace the plywood and screw in the Tapcon. If it spins and does not bite down into the concrete, replace it. If a new Tapcon of the same size spins and doesn't bite down, a larger diameter screw may be needed, or drill a new hole.

Fire officials discourage residents from leaving plywood up throughout the hurricane season. For starters, it's dark inside when the windows are covered.

Second, "Fire Rescue looks at these boards (of plywood) like burglar bars," Tampa Fire Rescue spokesman Capt. Bill Wade said. "Windows are designed so that someone can get through them in an emergency. If the boards are up, you can't get out. And we can't get in there to help you."

A boarded-up home can give the indication no one is living there, perhaps attracting burglars, and plywood can also attract termites and is a fire hazard, Chapman-Henderson said.

If you want to save your plywood in case it's needed again, keep it in a dry area. Lots of people put it up in the rafters of their garage so it won't absorb dampness standing on the floor. Some people also paint or varnish their plywood to give it a longer life. If it gets really soaked, plywood will eventually delaminate.

-- Times staff writer Shannon Colavecchio-Van Sickler contributed to this report.