DEAR SAM: My two-year-old house is located in an area with poor soil drainage, although the grade is satisfactory. A sump pump alleviated the problem when water came up from the basement floor, but another problem still remains. After a heavy rainstorm, my covered window wells fill up from the bottom and occasionally overflow into the basement. The cinder block walls, which are painted with StaDri, are stained from the water, especially at the windows, where it sometimes takes a week for the wells to drain. I have already bricked up one basement window, but am nervous about the standing water.

ANSWER: You probably have clay in your soil, which helps hold water rather than letting it drain. More important, the foundation shold have been of poured cement instead of cinder block, which is usually hollow. Also, with an engineered elevation above the water table, your basement floor would have been protected with an outside French drain along the perimeter and the walls would have had polyethylene vinyl covering imbedded in asphalt.

Install a French drain along the inside perimeter of the foundation and connect it to your existing sump pump. Any excessive rain will be absorbed by the drain and expelled by the sump pump to an area some distance from the house foundation.

For further relief, if necessary, the cinder block walls should be plastered with two coats of cement, mixed with Medusa waterproofing, for a thickness of at least one-half inch. The window wells should have connecting bituminous pipes that drain the water away at least one foot below the existng windows, if needed.

DEAR SAM: We have a problem with brick disintegrating on the lower level of our split-level house facing the hillside. The house is only 13 years old and already some bricks are falling apart.

ANSWER: You need the services of a mason to refurbish the brickwork, not only to replace broken bricks but to repair the brick joints with new pointing. Undoubtedly, the brick is only a veneer with a backing of cement block.

If any of the brick courses of the lower level are imbedded in the ground of the hillside, the surface water may be causing this deterioration. The mason may decide to plaster these underground bricks with waterproof cement, consisting of 1 part Portland and Medusa cements (ratio of 4 to 1, respectively) and 3 parts sand. Wait until the weather is warmer, however.

Because of the hillside setting, you need better drainage at this wall so that surface water will not flow against the house proper. An outside French drain five feet out and parallel with the rear wall can intercept the water and channel it beyond the sloping grade of the house into a storm drain or large drywell. Remember that your house walls are not intended to be retaining walls for surface water flow, unless they were originally constructed with French drains at the foundation footings, with piping connected to a storm drain.

DEAR SAM: I have two sliding Thermopane doors that barely move. The roller/wheels rattle, clank and hardly turn; I have to pull, tug and shove to open and close them. Now, one slider has broken its seal and condensation forms on the inside of the glass. What can I do?

ANSWER: You can look under "Glass" in your Yellow Pages and call Libby-Owens-Ford, manufacturers of Thermopane. The company will send its representative to inspect the doors and determine how old they are. If they are less than 10 years old, the company will replace them under its limited warrantly. There will be a charge for installation. They can tell you who can fix the rollers, which may have become corroded. If the rollers are nylon, there may be some obstruction in the track, such as a nail or pebble. Only an inspection will determine whether replacement parts are needed; there will be a service charge for parts and labor.

Samuel Fishlyn's address: 10 Maddoc St., P.O. Box 62, Newton Centre, Mass. 02159.