Question on Insulating Main Pipes

Larry in Phila

rjbphd--I have read the book, and the board. The pipe replacement was an emergency job, and it was done under a home warranty. I am not going to pull out 30' of new 3" copper pipe now to put back in iron (and everything else after that stretch was already copper...) The question is about insulation.

Larry in Philadelphia

Hey, all. I have a question about insulating my mains.
I have 1-pipe steam, about 42" of 3" copper followed by 21" 2 1/2" copper, and then several feet of 2", one long run, before the main vent and and then returning. When we moved in here last year there was only insulation on about the first 30', now gone because this section of pipe rotted and had to be replaced. The insulation was wrapped fiberglass batts.
I plan to replace this with fiberglass insulation, appearance is not a concern here and the premade is very costly.

Question 1--what thickness is sufficent? Do I need to work off long R-13 rolls, e.g., or can I go with thinner 2 inch that would be much easiewr to work with (though costlier!)?

Question 2--How far do I need to take this out? Heat loss is not a major issue as my first floor is old wood boards laid directly on the joists, so the heat from the mains gets directly to the first floor, but obviously I also want to give the steam less chancve to condense early (especailly as this is a 3 story house).

Question 3--How close to the heater and the headers pipes should I wrap this?

Thanks in advance for your suggestions.

Unknown

copper piping?

Replaced section of rotten piping? With copper again? Should be black iron pipes and then re insulated as a one time thing..

frank_25

seein' how ya put it that way...

2" is the thickness to use on ALL steam and dry rerturns.

Brad White_115

Insulating Copper

Yes, 2-inch is prescribed for piping of that size. One of course may argue that replacing it with iron and selling the copper at today's prices may finance the change and perhaps a cruise....