DEAR SAM: About 18 months ago, the paint an my metal-covered roof began to peel. A painter scraped it and repainted it -- on two brutally hot days. Last winter and spring, the new paint began to shed large flakes. It got worse with this year's cold nights. The previous paint supplier told me that there is no satisfactory roof paint being manufactured. Can you steer me in the right direction before I paint again"

ANSWER: Although the trouble may have developed from the abnormal temperature, I suggest that you have the next paint job done during more temperate weather.

According to a chemist of the Benjamin Moore Co., a satisfactory treatment for a metal roof would consist of the following: (1) On bare areas, apply a primer of Retardo that contains a rust inhibitive and a semi-sheen. (2) The finish coat should consist of Iron Clad, an oil base (alkyd) with good penetration. If the old paint continues to flake, you should "spot-prime" only these areas and apply the finish.

Use light colors that will reflect heat.

DEAR SAM: I have an oval dresser mirror, 12x15 inches, with wood frame, which has lost its shiny, goldleaf appearance. How can I restore it?

ANSWER: Depending on the value of the framed mirror, you can do it your self or take it to a professional.

If the gold leaf has tarnished, you may need a safe cleaner to restore its color. Hardware stores may have a mild silver polish and tarnish preventive for sterling, silver plate of gold. One such product is made by Hagerty & Sons, South Bend, Ind. 36624.

The cleaner should be applied with a soft cloth and then polished. The tarnish should disappear, if the original gold leaf has not deteriorated.

If a new golf leaf is considered necessary, you should look in the Yellow Pages under Artists' Materials and Supplies. You may check with several stores about gold leaf and instructions for application. In your local area, you may find that a "Book of Gold Leaf" is available for $12.95. "Siquid Gold Leaf Paint" sells for $2.95 per bottle.

If you prefer a professional restoration, check the Yellow Pages under Picture Framing.

DEAR SAM: Several rooms in the town house I'm remodeling have embossed ceilings and the paint is peeling to the base metal in many spots. The paint-removing substance used are not effective on the ceilings since the solvents don't soak in. How can these metal ceilings be stripped so that they will have a smooth finish when repainted?

ANSWER: I do not recommend the use of liquid paint-removers, even in stripping wood or furniture, unless the operation is done with excellent air ventilation. Methylene chloride chemical, usually an ingredient of such solvents, is hazardous to health.

You may remove the paint with sanders or you can camouflage it with a specific type of paint. Some methods include garnet paper on a wood block and hand-sand; an electric sander -- belt or disc type, or Sand-Block, which is available at many hardware stores.

Also, USG paint has a thick texture that will conceal the slight paint variations of the undercoat, even when not completely removed. If you prefer a "smooth" surface, you may use an acrylic latex paint with a filler in one or two coats.