After spending hours on my back in a dirt-floor crawlspace that had become a favorite with cats,  trying to thaw out a frozen pipe with an anemic hair dryer, I smartened up. The space was too tight and access too difficult to use a torch safely on the pipes. Nor could a torch or blower easily reach the most likely source of the problem: the spot where the pipes took a 90° turn to run up an outside wall to the kitchen sink.

On one long disgusting crawl back out to the light and air, I passed a pile of rocks. They were part of the backfill used to grade the site when the kitchen addition was added to the house years ago. I gathered up a supply of fair-sized rocks and popped them in the oven.

I baked the granite rocks, which were dry from having been under cover for years, at 450° for 30 minutes. Dense rocks such as granite store and transfer heat pretty effectively. Wet or porous rocks should not be heated unless you really want some excitement. They can explode.

I lugged the bag of baked rocks back under the kitchen and carefully wedged them around and atop the frozen pipes, stashing several on the sole plate where the pipes took their turn. After stapling a length of fiberglass insulation over the rocks and pipes, I went upstairs, opened a magazine and listened for the sound of running water. Sure enough, in about 30 minutes the blockage melted. I’m embarrassed to say that I’ve used this trick several times now on the same pipes.

Ralph Jimenez, Weare, NH