DEAR SAM: This winter, mainly, and other winters, too, have given me a severe problem on the outside of my home. Clogged, frozen gutters! With the slightests thaw, the snow melts and the water goes behind the wall shingles and wets the knotty pine finish in my den and even the rugs. Is there any way to defeat the route the melting snow takes? I have heard of electric devices but that doesn't seem to be the answer. There must be a better way and I'm hoping you can give me the answer. Surely a great deal of expense will entail if not corrected!

ANSWER: During two decades as a building contractor, I learned many tricks of the various trades, one of which concerned a better way to install roofing gutters. I called it a modified "dentil" which allowed not only the usual overflow of water at the front of the gutter but also at the back, without the adverse side-effects of seepage in the house walls.

Tooth-like "square blocks" appeared below the gutter at 16 inches on center, but actually they were rectangular and extended behind the gutter to project it at least an inche from the fascia board. This permitted a suitable opening at the rear of the gutter, so that melting ice (in winter) and excessive rainfall (in spring) could spill over. Rarely did any backup of water occur.

Homeowners should adopt this device when they are considering the installation of new gutters. In new home construction, there should be the additional safeguard of extended soffits, at least one foot from the house walls. But he modified dentils should be added simultaneously. Architects, who are designing custom homes, undoubtedly are aware of this precaution against backup of water.

DEAR SAM: Our home is a brick English Tudor with a slate roof, copper gutters and downspouts. We have rarely had trouble with snow during the past 25 years of occupancy but this winter has brought to our attention the hazard of snow-slides from the roof, which might injure pedestrians and, of course, break some of the foundation plants. The existing roof guards have deteriorated and we need something more substantial.

ANSWER: You are quite right in being concerned about snow guards for slate roofs. Although the slate roof has unusual longevity and is almost indestructable, it does require some maintenance.

David Levow, Inc. of Hackensack, N.J. manufactures the Fitrite snow guards not only for slate roofs but also for tile, corrugated metal, flat and batten seam metal, asbestos and asphalt shingle roofs. Naturally, the greater the pitch and size of the roof, the more the need for the protection.

Have your gutters or downspouts have been damaged by snow-slides in addition to the shrubs? If so, you need more than protruding shingle rings; also, you won't have the expense of replacing a substantially good roof when you can obtain Fitrite snow guards which are adjustable to any pitch. They are installed parallel to eaves and gutters and are set back one or two courses from the edge. They consist of pipes, two or three depending on the pitch, and brackets.

Howeowners with high pitched roofs of various materials may benefit similarly from Fitrite snow guards. For a descriptive brochure, write to the manufacturer (7 Georgia St., S. Hackensack, N.J. 07606) or in the Boston area, to Beacon Sales Co., 50 Webster Ave., Somerville, MA. 02143.

Samuel Fishlyn welcomes your questions on home improvements but can only include those letters of general interest in this column. Write to him at: 10 Madoc St. - P.O. Box 62, Newton Centre, Mass. 02159.