DEAR SAM: The steps leading to our home have crumbled because of the severe winter. They are set in a hill. The steps appear to be constructed of large gravel and pieces of flagstone, which are presently loose. The risers, in particular, have crumbled. My husband has in the past repaired smaller damage with epoxy-cement, but this winter that also crumbled. Can you help us repair our steps and walk?

ANSWER: For a substantial, professional job you should call upon a reputable mason. If your husband has the know-how, he can tackle the repairs as follows:

1) Remove all the loose masonry, including the flagstone and concrete sections of each step individually, possible making a paper sketch as to the present placement of each flagstone in the tread-walk. Remember that flagstone when wet is quite slippery and it might be better to eliminate it and use a cement "float surface" for better traction. If you prefer to use the flagstones, they must be set over a good base of Portland cement and held in place by mortar dabs beneath them and by full mortar joints.

2) Since the risers have disintegrated, these should be built first. The ground pressure indicates that a least six inches of area fronting the rise should consist of solid masonry. Dig away this area, place a 2x8 of the correct length for the riser, 1x8x10-inch end-pieces, nailed and braced, and fill the cavity with a cement mixture of 1 part Portland cement, 2 parts sand and 3 parts peastone gravel (or equal).

3) Prepare each tread (or section of walk) with a frame of 1x4-inch strapping, extending up two inches for receiving the new combination base and suface. You will not need the flagstones, unless you wish to install first a one-inch base, permit it to dry, and then apply the mortar dabs and mortar joints to implace the flagstones. A level is necessary to make each frame accurate, which should be supported by horizontal 1x2 strapping and stakes.

4) A cement edger is needed to round off the edges along the strapping. This is used after the cement has set slightly and a wood trowel has provided a float finish. Also, this edger achieves a "smooth" perimeter border and prevents any breakage in the cement, when strapping is removed.

Samuel Fishlyn welcomes letters on home improvements and will include those of general interest within the limited space. Write to him at Box 62, Newton Centre, Mass. 02159. For a personal reply, please include a self-addressed, stamped envelope.