The ups and downs, ins and outs, of buying the right ladder

Fruit trees have to be pruned, houses painted, and living rooms wallpapered. All these jobs require a ladder. This means selecting the right ladder for the job, maintaining it properly, and using it with safety and care.

Most homes call for at least two kinds of ladders:

* An extension ladder that is high enough to work on the highest peak of the house.

* A stepladder for inside and some outside jobs.

The stepladder, when opened, should be high enough to do a job without overreaching or standing on either of the top two steps.

Determining the length of the extension ladder is a bit trickier. The rule of thumb is to allow 6 or 7 feet more ladder than the height you wish to reach. Most hardware and home-supply stores have charts to help you figure the ladder length right for your needs. Ask for them.

In buying ladders, you have a choice of wood or a lightweight metal such as aluminum.

The main advantage of aluminum is its light weight. Even a long extension ladder can be handled fairly easily by one person. Aluminum conducts electricity , however, and should not be used near power lines, for electrical work, or even in conjunction with power tools. Also, it is unstable in high winds.

A wood ladder is less expensive, will not conduct electricity, and is more stable than aluminum. But it is heavy to lug around and will deteriorate if left out in the rain.

Consumer Reports magazine gives wood ladders the edge over aluminum, since they are more rigid, stronger, more stable, and cheaper to buy.

Wood ladders will also last longer if they are periodically given a coat of shellac, varnish, or linseed oil. Never paint any type of ladder, wood or metal. Paint may hide unsafe defects and cracks.

Check to be sure the steps of your ladder are thick, deep, and well braced. Look for nylon pulleys and nonrotting poly-propylene rope on extension ladders. Make sure that the ladder has steps with a nonskid surface and that all four feet of a metal ladder have nonslip plastic or rubber tips. Most high-quality metal ladders today have these tips, but if you have an old ladder which does not, you can remove the danger of slippage by attaching ordinary shoe heels to each foot of the ladder.

Shelves should fold completely into the ladder. Wood shelves should hold at least 25 pounds, and metal shelves at least 50 pounds. Remember, though, the shelf is meant for paint and tools, and is not built to hold your weight.

Don't be afraid to test any type of stepladder that interests you. Open it in the store and see that the spreaders lock into position properly. Then stand on the second step from the bottom and grab the side rails. Shake it. Rock it. Sway it. How steady does it feel? If you feel insecure, buy another model.

Once you buy a ladder, what matters most is the way you use it. The Consumer Product Safety Commission gives the following advice for ladder users:

* Be alert whenever you're around a ladder.

* Face the ladder while climbing or descending.

* If you cannot reach a point, move the ladder, not your body. If the ladder must be moved, get down and move it. Don't jiggle or walk it to a new position while standing on it.

* Wear slip-resistant shoes.

* Observe the highest-standing-level labels.

* Never climb higher than the second step below the top of a stepladder. Never climb higher than the fourth rung from the top of an extension ladder or the level marked on the label.

* Don't leave a ladder unattended. It could be a hazard to children.

Proper maintenance will add years of service to your ladder. It should be stored away from heat and moisture in a sheltered place. Hang it horizontally on hooks or racks (shelf brackets are good) supported at enough points to prevent sagging.

Many homeowners find that the inside wall of the garage makes an excellent storage spot. You may want to attach an ordinary window lock on each side of your extension ladder to lock the two sections together for easier moving.

When the ladder is broken, bent, or twisted, or has been exposed to fire or chemical corrosion, it's time to dispose of it. Be sure you destroy it immediately so that no one else will be tempted to use it.

When using a ladder of any type, always keep a rope handy to anchor it securely whenever there is danger of slipping or shifting. If you plan to use it to walk on the slope of a roof, always use a rope as an anchor. This can be done by throwing the rope over the top of the house and anchoring it to a tree or some other firm object on the other side.

If there is a possibility that you will be mounting your ladder with mud, paint, or other slippery debris on your shoes, you would do well to install a corner brace to one leg of the ladder for use as a foot scraper. By cleaning the soles of your work shoes, you are not only making your ascent safer, but you also are keeping the ladder cleaner.

The most important point to remember, however, is that no matter how safe and well maintained your ladder is, it is only as safe as the manner in which it is used. And you are in charge of that!