Advice Requested Re Steam Pipe Insulation

Emily718

Hello. This is my first post here. I recently read about Dan in The New Yorker magazine and ordered his book We Got Steam Heat. We have owned our 1890s brick townhouse in Brooklyn for 3 years. I investigated our system and discovered that our basement steam pipes are completely uninsulated (also, not enough air valves and pressuretrol at incorrect pressure). We decided to tackle the insulation ourselves. My husband and I measured the pipes and based on posts here, I ordered a fair amount of fiberglass pipe insulation from Buy Insulation Products.com in 1.5" thickness (18 3-foot pieces of 2.5" pipe insulation, and 6 pieces of 2" pipe insulation) - we will need more but wanted to get started with this. The insulation arrived the next day, and we were excited to get started this weekend on improving our system. We just went to the basement, and it looks like we may have mismeasured the diameter of the pipes or they sent the wrong product. When we measured the 2.5 inch diameter pipe clamshell, it appears to have a 3" diameter opening. This does not fit tightly around the pipe, it hangs loosely on it. (Pictures attached.) My question is, can we still use the loose clamshell insulation? Will it work to insulate the pipes even if it is loose?

I know there are so many experts on this board. I am grateful for your advice. Thank you in advance.
Emily

New England SteamWorks

1. They should fit very tight. Either you mis-measured your pipe, or you were mis-shipped. On their adhesive strip each roll of insulation has the size printed on it, pipe size x insulation thickness. If you have 2-1/2" pipes yours should read 2-1/2" x 1-1/2". Does the marking match what you ordered? Does the 2" pipe insulation you ordered fit on the pipe in the picture?
How to measure pipes
2. Insulating the fittings is also important. You can get the PVC fittings from the same source. If you mis-measured you'll be tempted to use what you have, but then the PVC fittings won't fit, and your insulation job won't be ideal.

Emily718

Yes, I am sure I mismeasured because the 2" insulation fits. Can I trim the oversize clamshell to fit by cutting a strip off one side of the clamshell? I don't want to pay to send it back. Thank you.

KC_Jones

For steel pipe:
2 3/8" OD = 2" pipe
2 7/8" OD = 2 1/2" pipe
3 1/2" OD = 3" pipe

vaporvac

Emily718 said:

Yes, I am sure I mismeasured because the 2" insulation fits. Can I trim the oversize clamshell to fit by cutting a strip off one side of the clamshell? I don't want to pay to send it back. Thank you.

Try it on one section and see. Be sure to report back your findings.

Fred

You cani it with a sharp razor knife or box cutter. If you got tape strips that are seperate from the insulation, just trim the insulation. If you got insulation the has an overlapping tape strip attached, cut the insulation from the side that does not have the tape strip on it. Should be fine.

New England SteamWorks

Yes, I am sure you coud trim it to get it up there. But you'll be adding a lot of additional work for less than ideal out come. I would suggest you sleep on it. A little time might make you feel better about sending it back. After all, you went to the trouble to try to do a bang up job by ordering 1-1/2". If you plan on staying, you'll be looking at your work for a long time.

Emily718

I am going to see if the company accepts returns. If anyone knows of a supplier where I can buy these in person here in Brooklyn, please let me know!

LarryK

I think you're best off ordering it. There is a 24hr plumbing supply with lots of steam stuff in Clinton Hill, but they don't stock 1" and the 1 1/2 is going to be even harder to find and it would take the same amount of time to get it.

New England SteamWorks

Personally, I like those BuyInsulation guys (I'd be surprised if they didn't accept a return). And I find it easier to order online then going through an intermediatary who may, or may not be familair with the whole system, especially when you start to order the PVC fittings with all the different sizes. That's enough to drive a counter guy nuts, but not your computer. And everything is in stock.

BobC

i agree they are good at what they do but the shipping is a bit much (oversized rates).

Bob

Emily718

Hi. In the process of exchanging the oversize pipe insulation, I am doing a much more thorough job measuring the basement pipes for insulation including the near boiler piping. It is going to turn into quite a lot of insulation (e.g., current figures are 72.5 feet of 2" pipe insulation, 18 feet of 1.25" pipe insulation, 11 feet of 1.5" pipe insulation, and some additional pipe I have to remeasure, plus a lot of L, T, and other fittings covers. I had previously ordered 1.5" thick fiberglass Owens Corning insulation (see pics above). Would it be sufficient to use 1" rather than 1.5" insulation? Most of the pipes are in a basement; it's not cold down there (but not hot either). There is a fresh air intake in the boiler room meaning there is a cold draft coming into the boiler room area. Would it be OK to use 1.5" thickness for the near boiler piping (near the fresh air intake), but 1" on the rest of the piping?
Thank you,
Emily

ChrisJ

Just thinking out of the box here but,
Won't the slightly oversized insulation perform just as well assuming there's no gaps between the sections?

Personally i'd rather have the oversized 1.5" instead of tight fitting 1" if those were my two options.


As far as where you use thicker, I'd use the 1.5" in any cooler or cold areas. I wish I had in my crawl spaces, or even 2". Near the boiler is the last place you should use it assuming the boiler is under a heated space (livingroom, bedrooms etc). Chances are most of that heat goes up and ends up in the livingspace anyway. This doesn't mean don't insulate it, just means 1" is plenty.

Emily718

ChrisJ: commenters above said the insulation should fit snugly, not be oversize. Hatterasguy, My kids are still little (7, 9), so we are probably in the house for at least another 15 years, possibly 20. Still, thinking of going with 1" just because, well, it seems probably sufficient.

ChrisJ

Emily718 said:

ChrisJ: commenters above said the insulation should fit snugly, not be oversize. Hatterasguy, My kids are still little (7, 9), so we are probably in the house for at least another 15 years, possibly 20. Still, thinking of going with 1" just because, well, it seems probably sufficient.

Hi Emily,
I'm aware of that and they are correct.
However, if you end up paying shipping costs on this due to the mistake, I'd be considering using it anyway. Your problem is going to be making sure all joints are tight between the sections of insulation and the ends must be sealed. As long as air from that gap can't escape, it'll perform well.

If you want it to be perfect (which I always do) then you need to swap it for the right size. I'm just not sure it's financially the right thing to do.

ChrisJ

Hatterasguy said:

It takes 11 years to payback the difference in cost between 1" and 1.5" assuming gas at $1/therm.

Anybody suggesting 1.5" ought to be sure you're staying there awhile.

This is assuming fuel stays at these costs and it's assuming a set ambient temperature around the piping, no?

Didn't we figure out the payback would be quicker with a 30-40F ambient (my lovely crawl spaces, etc)?

ChrisJ

Hatterasguy said:

Correct.

Also assumed 2.5" pipe.

The disparity in cost is presumably less with 2".

All of mine is 2"
You sure you did 2.5"?

Emily718

Thanks to you for your comments. The shipping costs are extremely upsetting. I am trying to work out a solution with the company.

ChrisJ

Emily718 said:

Thanks to you for your comments. The shipping costs are extremely upsetting. I am trying to work out a solution with the company.

@Hatterasguy What's your opinion on my idea for them to use the incorrect size insulation and just keep all the seems tight in between sections and fill the ends to ensure no air leakage?

I think that oversized insulation could be made to work fine with a little attention. Especially since the shipping costs are the painful part.

ChrisJ

So worse case scenario, buy a length of the proper size insulation and cut that and install pieces of it at the ends of your run to seal the ends.

Emily, I'd use the insulation you have. Just keep the seams between the pieces tight and tape them. Do what you can to seal them at the ends, like using the suggestion I had above.

It'll perform fine, probably look fine and save you a lot of money.

Emily718

Thanks you guys! This is great information!

Emily718

I may end up hiring someone to put this in -- my aunt has made me nervous about working with fiberglass. Would anyone have a recommendation of an appropriate individual to properly install the pipe insulation? I am in Brooklyn, NY.

vaporvac

Quick question on sizing. I'm going to buy 2" for my unconditioned garage, but planned on 1" for my NBP and a small bit of basement just before the garage. However, there was a post by @Paul Pollets and @Brad White that said this:

Not less than one-inch thickness of moulded fiberglass insulation on steam as a functional minimum. The energy code here in MA has this at 1.5 inches for piping up to 2" size and 2" thick above that. Just a point of comparison, but no one will arrest you yet.

Most people seem to have 2" pipe, but mine is all 3" and 4". Do I really need this thickness in the basement or can I get by with 1" as planned? It's a lot more expensive given my large pipes
And what the heck in an insulation diaper. I can't seem to find a pic.

Fred

1" is fine in a basement. MA has a lot of, what seems to be considerably more stringent code. The question is how many people follow them, especially on retrofits. New Construction, probably. 1.5" may be better but I don't know what the payback might be. 2" in an unconditioned above ground garage, I would agree.

vaporvac

Any pics of a diaper?
Have any non-pros done the High temp cement with mastic approach instead of fittings? Is this cheaper, more work, more difficult? Any tips from the pros?

ChrisJ

vaporvac said:

Any pics of a diaper?
Have any non-pros done the High temp cement with mastic approach instead of fittings? Is this cheaper, more work, more difficult? Any tips from the pros?

Here's one.
Not sure why, but you asked and I aim to please.

vaporvac

That is about all I'm getting searching for a pic of insulation diapers!

ChrisJ

Oh.
What's an insulation diaper!?

Fred

Could they mean Tee Fittings for pipe insulation??
http://www.statesupply.com/pipe/insulation/fiberglass/fitting#./fitting?&_suid=145383586910303677092142892027

vaporvac

I think that's what most pros use. the diapers are cheaper, I think. I'm not sure. The co's list them, but don't show a pic.

New England SteamWorks

I am not a fan of the mastic approach. It's messy and not as visually appealing. I also think it doesn't insulate as well, but that is just a guess. Where it does come in handy is for fittings in impossible to reach locations.

The fiberglass wadding for the Tee fitting is just a rectangle, but the shape for an elbow is sort of like a reverse diaper, if that is what they mean.

vaporvac

Interesting. I think gerry gill ? (maybe) mentioned he did his all with High-temp cement with mastic over scrim. I do have some crazy places super high up; we'll see what is easiest when I'm up there. I bought all my insulation today and figure I'll deal with the fittings after. That should get me 90% there, I hope. My silly NBP has a zillion 90s and 45s since I have the two boilers, each with a drop header into yet another drop header.
My last bit of mains and returns has a runout for a couple of rads, but has a big ol' shut-off valve to both the runout and return at the 45%. Has anyone seen that before? There are shut-off valves at the rads. It's very strange and I'm just now noticing it.
I got my insulation from a local Cincy place specializing in industrial and commercial stuff for a very competitive price, cheaper that ordering from the web (and the local plumbing shops), all in stock and pulled for me within 20 minutes. They were so nice.
P.s. sorry for totally hijacking this thread.

BobC

The problem with ordering online is the shipping is crazy (oversized rates).

Bob

ChrisJ

BobC said:

The problem with ordering online is the shipping is crazy (oversized rates).

Bob

Hatterasguy said:

BobC said:

The problem with ordering online is the shipping is crazy (oversized rates).

Bob

At $4.83 for 3' of 1.25"...........I'll suffer with the shipping............

@BobC

Where are you able to get quality pipe insulation cheaper?

vaporvac

I bought mine locally at Kremig Insulation for less. How much less varied by size, I can't imagine there aren't other major suppliers elsewhere. This wasn't my local pluming supply house, but an insulation specialty place. Of course, I pay tax, but the difference in price and possible shipping made up for that in a few sections. they also had EVERY size I needed. Call around. Online is obviously great for those living remotely, in small towns with no other option.
@Hatterasguy and @ChrisJ , where did you order from, ooc?

ChrisJ

I did 3 orders from buyinsulationproducts.com

First one was a huge order to do 90% of my piping.
Second was to do my dry returns.
Third was to re-do my header after it got wet from the cheap king valve leaking.

vaporvac

Does anyone have instructions for putting on a (insulation) diaper? How does it stay on.... zip ties. Does it NEED something over it?

ChrisJ

What is an insulation diaper!??!?


If it's a PVC fitting cover you wrap the fiberglass around the fitting and then cover it with the PVC cover and tape or tack it.

BobC

I used lacing cord on mine and then put the plastic covers over it.

Bob

vaporvac

Are the plastic covers necessary or just for looks?

ChrisJ

vaporvac said:

Are the plastic covers necessary or just for looks?

Keeps the fiberglass clean and from getting snagged on stuff etc.