Water Pipes

[mjb]

What is the best insulating material to use for hot and cold water pipes under a crawlspace? There is no insulation on pipes to be seen and I would like to prevent a disaster.

[AllanJ]

Look into the insulation used for steam heating pipes.

No matter how much insulation you put on the pipes, the danger of freezing exists unless you have at least one of:

1. The metal of the pipe itself conducts heat from the living space down to keep itself from freezing and the longer the span in the crawl space and the lower the temperature in the crawl space and the lower the R-value of the insulation you put on the pipe, the more difficult it is.

2. The water is turned on often enough or allowed to trickle enough in all lines so that movement of water prevents any one section of pipe with water still liquid inside from becoming solidly isolated after which time bursting occurs when that section finally freezes.

3. The temperature of the crawl space is above freezing.

I would do whatever it takes (do what I have to), including exhausting air from the living space down to the crawl space, to achieve #3. Should a power failure prevent #3, the plumbing system should be drained. Installing drain valves in the low points which would include several valves in the spans in the crawl space, is a good idea.

Other home handyman hints:
http://members.aol.com/ajaynejr/home.htm