THERE IS always one kid on the block who gets everything he wants. On our block he was Tom Bumbry (who went by another name), absolutely the only kid around who had his own Hammond organ to fool with by the time he was 12. Simply disgusting.

One day I taught old Tom - good old spoiled Tom - a lesson in frugality. I invited him along on one of the gang's regular excursions into the nearby forest. There we lived off the land for a summer's afternoon, building in a dark corner of hardwoods a lean-to shelter I assured Tom would stand up under any conditions.

We covered the reeds and branches with oak leaves as thunder rolled up from the western skies. I assuaged Tom's cries for mommy with stories of how well the Indians had made out in similar shelters. It rained and rained and for five minutes or so we were safe and dry under out rood of leaves and happy and full of wonder at our genius. Then the whole thing collapsed. Tom ran home screaming and I was forbidden ever to use his basketball hoop again.

That's the thing with roofs. You just never know.

They stopped using leaves as roofing material about the same time they invented corn. Still, occasional leaks are known to spring.

These can occur in many areas of a roof: worn, broken or missing shingles, a hole, pitted flashing or lost caulking. Leaks, native to Washington government offices, are mysterious things. Often they will wander far from their source before entering the house in the form of a drip or stream. Ancient methods of accurately locating a leak's source have been lost. However, it can be traced approximately by crawling through the attic, finding where the water enters and sticking a wire or a nail through the roof at this point far enough to be seen from the outside.

The leak seaker must climb on the roof and resume his search.

Several home improvement books include information on leaking roofs and what to do about them. Among these are Home Maintenance (by William Weiss, Scribners), Home Repair (by Gershon J. Wheeler, Reston) and Home Remedies (by Christopher Fahy, Scribners). In searching for your leak, beware of Fahy's story line. It can easily lead you into the next chapter, dripping notwithstanding.

Some roof repairs can be done yourself, once you have located the trouble spot. If it is an asphalt shingle that has broken or worn through, you can mend it by sawing through the nails with a hacksaw, (or prying them out if you can reach them without breaking the shingles in the row above), replacing the shingle with a new one and nailing it back in place. Use only galvanized roofing nails with the extra-large heads. Nails with smaller heads can pop through. If the shingle is self-sealing, there's no need for roofing cement. Otherwise cement should be smeared under the shingle to keep it from flapping around.

Working on the roof can be a tricky business, what with falling and all, and many homeowners would rather somebody else do it. The Washington Center for the Study of Services reported on roofing repairs in its Winter 1977 issue of Washington Consumer Checkbook (ask for it at your library). In its usual thoroughness, the center gave many tips in contracting a firm to fix your roof, plus a complete index of two dozen Washington area outfits, what services they offer and how they rated with readers who had employed them.

If you are able, you will lessen the possibility of big surprises on the final bill if you know what is wrong with your roof and how much work is required. Ask several firms for an estimate and for references. Some may have already done work in your neighborhood. When you have narrowed your choices, call the local consumer affairs office and ask what, if any, complaints have been registered against them.

"Most problems I've seen have to do with skylights, leaks around the skylights," said Dennis Marquise, home improvement investigator at the Montgomery County consumer affairs office. "Certain companies won't touch certain jobs. The better ones can foresee problems occurring and won't do the job. Most of the complaints we have concern four or five firms."

When you have chosen a company for the job, begin nothing before you sign a contract.

Insist on a contract that specifies the repairs to be made; the materials to be used; and that the firm remove all debris when the job is completed. Write into the contract that the firm also secure a building permit, if possible in your jurisdiction; when the work will begin and how long it will take; the full price for the job; how undorseen repairs will be priced; and how the payments will be made.

A number of roofers require payment only after the job is complete and the customer satisfied. Beware of those who want the full price up front. Push for a written guarantee. Warranties on some materials range from 15-25 years. But often these are extended by the manufacturer only as far as the installer, who must decide in turn how much to pass to you. Warranties on workmanship are often no longer than a year.