Fiberglas pipe insulation (white paper with yellow glass inside)

[Techie1961]

I have been working with the Fiberglas pipe insulation sticks for quite a while. They are the white ones that are split and have an adhesive strip to hold them on. The one thing that I haven't been able to figure out is corners, tees, etc. Does anyone know how to do fittings so that they look professional?

 

[rlitman]

For my house, I use mitered joints, but in every professional installation I've seen, they use plastic elbows and white paper tape.

 

[Rookie2]

A salesman showed me how easy it was to cut using a serrated steak or bread knife. The plastic elbow is the only way to go if you are on a job.

 

[Ron Lombardo]

They make ZESTONS for the tees and 90's held in place with tacks and the inside filled with loose insulation that comes with them. I usually don't use the Zeston Tees ... i do what they call STOVE PIPE tees. I run the pipe insulation past the tee and cut out tight for the pipe on the bull of the tee ... then come back and cut the end of the section of insulation concave so it fits over the side of the pipe insulation on the run. They make a product called CP-11 which is a thick white mastic to paint the ends and joints.

Yes a steak knife or larger knife very sharp works best to cut.

 

[Techie1961]

For my house, I use mitered joints, but in every professional installation I've seen, they use plastic elbows and white paper tape.

I've been told about the mitered approach but when I try this the elbow or tee is too large. It kind of makes a messy looking connection with it bulging. Do you use a larger size insulation so that it will go over the fittings? The proper size fits really close to the pipe walls.

 

[Techie1961]

They make ZESTONS for the tees and 90's held in place with tacks and the inside filled with loose insulation that comes with them. I usually don't use the Zeston Tees ... i do what they call STOVE PIPE tees. I run the pipe insulation past the tee and cut out tight for the pipe on the bull of the tee ... then come back and cut the end of the section of insulation concave so it fits over the side of the pipe insulation on the run. They make a product called CP-11 which is a thick white mastic to paint the ends and joints.

Yes a steak knife or larger knife very sharp works best to cut.

I find that one of the FatMax knives with a carbide edged blade works really well also. I extend it fully and lock down the screw. It gives about a 4" blade.

I have thought about the plastic coverings but I don't use plastic on the straights since my customers won't pay for them. I have thought that it wouldn't look good with paper on the straights and plastic on the fittings.

 

[Ron Lombardo]

The fittings come numbered ... GOOGLE Zeston® 2000 PVC Insulated Fitting Covers there is a pocket guide ... for copper pipe or iron pipe ... they are sized by the pipe size and thickness of the covering.

There is also a new product i like its called venture clad ... its an aluminum sticky back for covering exterior duct and piping ... it think it has a lot of other uses.