Steam Heat - Replacing pipe insulation

Lori_2

The asbestos insulation is being removed from the steam heating pipes in my basement. What material can be used to insulate them and where can it be located?

Tom Giedraitis

1" Fiberglass is commonly used.
I have some left over from when I did my steam lines if you're intrested. Otherwise, look in the yellow pages under insulation and find someone who sells it.
HD usually won't have it.


Tom

Brad White_2

1 inch is just a place to start

At least here in MA and model energy codes in many places require at least 1.5 inch thick (not even 1 inch is mentioned in the 201-250 degree F. category you are in).

You could use the 1" mentioned as a base layer and "nest" other thicknesses over it to the new outside diameter.

Realistically, though, the first inch does most of the work.

But my advice is to follow the code and put in at least those thicknesses. It will shorten your cycle times (burner on to heat at the radiators) and will out-perform the old asbestos insulation by half.

The code table reads thus:

Pipe Size(s):Thickness of Insulation*


<1" :1.5" thick


1" to <1.5":1.5" thick (this range ought to cover your branches).


1.5" to <4": 2" thick (this range ought to cover your main size)

* This thickness presumes a k factor of 0.25 to 0.29 and this includes fiberglass. Do NOT use foam insulation. It will melt.

Lori_2

Thanks for the info. Are there different types of fiberglass? Can I just get a roll of fiberglass with kraft paper backing that is at least the appropriate thickness and wrap the pipe with that?

FRANK_24

YOU CAN GET ALL THE INSULATION YOU NEED AT YOUR LOCAL PLUMBING SUPPLY HOUSE. JUST ASK FOR FIBERGLASS INSULATION WITH THE NOMINAL SIZE DIAMETER. THERE IS NOTHING SPECIAL ABOUT THE TYPE. YOU SHOULD USE GLOVES, AND PROTECTION FOR OTHER AREAS OF EXPOSED SKIN AND A GOOD DUST MASK. THIS MATERIAL HAS NOT YET MADE THE LIST OF HAZARDOUS MATERIALS (THAT I KNOW OF ) BUT IT WILL CREATE ITCHING AND WHO NEEDS TO INHALE LITTLE SPECKS OF AN IRRITANT?

Brad White_2

To expand on Frank's comments

what you want is termed "molded fiberglass" ("moulded" if you are in Canada :^)> ), and is covered with a white all-service jacket (ASJ) which has ripstop nylon over foil and under a white kraft paper outer jacket. Ask for self-sealing strips. Johns-Manville, Knauf and Owens-Corning are typical names you may find. There are others.

Fittings are covered with fiberglass blanket inserts (diapers I call them) then jacketed with PVC covers and sealed with white PVC tape.

I recommend that you do the steam mains and branches first, then go back and do the fittings. Fittings can be tedious and can make or break the appearance of a job. I have often said that insulating pipe is an easy job to do but a hard job to do WELL.