I just had a new boiler installed - forced hot water. It's very nice, but in the process, I have lots of new piping running across the cold, cold basement.

I've looked at several types of pipe insulation, and I'm not happy with any of them.

At the big box stores, I get foam insulation. That's pretty nice, but it's kind of flimsy - it's only 3/8" of foam, and my old insulation was 5/8" of foam. 3/8" just doesn't seem like enough. According to the manufacturer, they're about R-2.

I tried the jointed fiberglass tubes, too. Also, just R-2, and I'd rather have the foam than more fiberglass.

I looked at Reflectix, an foil-coated air bubble sheet that can be wrapped around the pipe and stapled close. They claim R-4, but I'm doubtful. How much of the energy that I'm losing is radiant?

Any suggestions on how I can get some decent insulation on these pipes?