DEAR SAM: This summer we purchased a colonial-style house at Cape Anne, Maine. We made some necessary refurbishments and felt quite content until a few days ago. The temperature outside hit 10 degrees below but we couldn't raise the house temperature higher than 65 degrees (without the fireplace). The attic floor already is well insulated. Storm windows and doors are tight. And the hot water boiler (with gas fuel) functions well. We wonder how to insulate the crawl space and how to improve the heating during cold weather.

ANSWER: The test of a heating system is usually determined under such conditions. You are wise to insulate the crawl space immediately, which will require 50-pound asphalt roll paper or polyethylene plastic to preclude the rise of ground moisture through the floor.

Most importantly, the floor joists should be insulated at the crawl space with full-thick blanket (R-11, Resistance to heat flor). The vapor barrier should face the living quarters to prevent room moisture from penetrating into the fiberglass. An insulating mechanic can easily staple the blanket between the joists, using "reverse tab" insulation.

When your fireplace is not being used, close the damper tightly to reduce the loss of house heat through the chimney.

The hearth opening should be blocked with plywood -- cut to fit snugly and covered with aluminum foil on the inside -- to stop drafts. The outside of this panel can be painted fireplace red or black to make it inconspicuous.

Aluminum foil should be placed behind each standing radiator to reflect heat, giving it better direction and dispersion.

Finally, I would recommend that you inspect the present water temperature gauge of the hot water boiler. If set at 140 degrees, it should be adjusted with a screwdriver to 155 degrees. Higher water temperature for the radiators should improve your room comfort as needed.

DEAR SAM: I've had my driveway and yard paved with new asphalt. The contract specified the price and a five-year warranty against cracking. When the work was completed, the contractor stated that "after one month, seal coating is necessary and it would cost $150 additional." He never mentioned this before; I thought I was getting a complete job. I am a widow and a senior citizen and I can't afford this extra cost. Can I hold him to his contract? Do I really need the seal coating?

ANSWER: Since the work was completed in October with freezing weather still a few months away, you should check the paved asphalt for any cracks. If you find some, you should advise the contractor of the conditions of the warranty and ask that he make immediate repairs. Call upon friends to assist you in the inspection.

Simultaneously, send copies of your letter and contract to your state's office of consumer affairs for assistance.

P.S. Adverse effects usually do not appear unless the asphalt pavement has cracks which will allow the penetration of rainwater. The purpose of seal coating is to limit the porosity of the asphalt and to cover up some blemishes; also, it is used in older asphalt driveways to improve their appearance.

Samuel Fishlyn welcomes questions on home improvements but can include only those letters of general interest in this column. His address is 10 Madoc Street, P.O. Box 62, Newton Centre, Mass. 02159.