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Flow of Cool, Dry Air Can Help Reduce Mold

February 09, 1992| From Popular Mechanics

QUESTION: We are having a problem with mold growing throughout our new home during the winter. The house is brick and the walls are insulated well, including the windows. We have ceiling fans in every room. We've kept the thermostat at 68 degrees Fahrenheit. How can we prevent the mold from returning, especially in closets?

ANSWER: You must introduce cooler, drier air into your house, since it's so well insulated and draft-free. You can duct fresh outside air into your hot-air heating system plenum, but it should be dampered and connected to a humidistat set to go on when your furnace does. You can also preheat this air, but in order to do so you should consult a licensed mechanical engineer.

Your house is now so tight that cool, dry air cannot leak in under doors and around or through unsealed windows or through uncaulked gaps in the walls. This drier air would offset the moisture produced inside your home by normal living--steam from showers or baths, and cooking.

Adding exhaust fans in the kitchen and bathroom can help solve the problem. Opening a window once a day and running these fans for 10 or 15 minutes should help. Experiment with how wide you open the window and how long you run the fans. While this will negate some of the energy saving built into your new house, it can solve the mold problem.

Visual Distraction May Scare Off Woodpecker

Q: Every spring, it's great to hear the songbirds come back, but along with them we also get a plague of woodpeckers. While these birds can be decorative, they seem to find my house, with aluminum siding, particularly attractive. Their drumming makes a constant racket and they even dent the siding with their beaks. What can I do to drive away the woodpeckers, preferably without also getting rid of the songsters at the same time?

A: For woodpeckers, drumming serves the same function as singing does for other birds. They're establishing a territory and attracting a mate. Houses serve as a fine resonator and amplifier for the drumming sound, so the birds find them more satisfactory than most trees.

There's also another attraction for the birds. Some insects may spend winter months in the small spaces they find in your home's siding and other features. Other insects bore into the wood. They're all food for the woodpeckers.

Our suggestion is that you should start combatting Mr. Woodpecker as soon as he starts.

In order to drum, the bird must be able to hold onto the structure. Therefore, you should try to remove ledges, cracks and crevices which might make good footholds.

Although chemical repellents are sometimes effective, we've had somewhat better success using visual distractions. Mothballs hung in an open mesh bag--an old nylon stocking works well for this--are the usual chemical attack.

We tied foil pie tins and strips of aluminum foil on three-foot-long strings and hung them from our soffit at three- to four-foot intervals. The slightest breeze made the foil sway and twist enough to keep the birds away.

These scarecrow techniques should not discourage the songbirds because they like the bushes next to your home.

Reconstituted Wood Comes in Wide Variety

Q: Can you give me a brief explanation and use of the various type of wood panels available (aside from plywood) such as particleboard?

A: The panels you are referring to are known as reconstituted wood panels. Particleboard is the most widely used and known in this group. This non-veneered panel is made from wood chips bonded with resins under heat and pressure.

Industrial grade and underlayment are the two most common types. Industrial particleboard has a fine finish and is used in furniture and cabinets under a plastic laminate. Underlayment particleboard goes over a subfloor and under carpet or tile. Standard thicknesses are 1/2, 5/8, and 3/4 inch.

Waferboard is similar but made from wood wafers. Its distinctive wafer pattern makes it popular for cabinets, storage bins and craft projects. Construction uses include wall or roof sheathing, subflooring and underlayment. Sheets are available in 7-16ths, 1/2 and 3/4-inch thicknesses.

Oriented strand board (OSB) is like waferboard but has thin wood strands instead of wide wafers. The strands are mechanically oriented in perpendicular layers like plywood veneer grains and then bonded with phenolic resin. Considered to be one of the strongest reconstituted panels, OSB is used like waferboard. Besides standard 4x8-foot sheets, larger panels up to 8x24 feet can be ordered in thicknesses from 1/4 to 3/4 inch.

Hardboard is made by interlocking refined wood fibers and then compressing them into thin, hard, impact-resistant sheets with heavy pressure rollers. The well-known Masonite is a hardboard. It's used where low weight but not high strength is needed for such things as cabinet backs. Use hardboard where good finishing qualities are needed.

Tempered hardboard has been treated to improve stiffness, hardness and finishing properties. It can be used outside for shutters and door panels. It comes in 1-16th, 1/8 and 1/4 inch thicknesses.

Fiberboard, also called grayboard, is a non-veneered structural panel used for carpet underlayment, sound deadening, exterior siding, wall sheathing and protective floor cover-up. Standard panels are 4x8 but they also are available in 4x10, 4x12 and 8x12 sheets, 1/2 and 5/8 inch thicknesses.

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