Insulate steam pipe half set into garage ceiling

JH3550

I am looking to insulate two steam pipes that run along the ceiling of my garage to heat a room above. Part of one of the pipes is half in the ceiling (picture attached). Can anyone suggest how to insulate that part? I was planning on using fiberglass insulation on the rest. What thickness would people recommend?

The house has a one-pipe steam system. It was built in 1924 and the garage and sunroom above were added in 1929. The radiators in the sunroom are not getting hot, and the previous owners installed an in-wall electric heater. The system works fine for the rest of the house; heats evenly, runs quietly, etc.

Thanks!

random12345

I have the same problem in my garage. I would like to hear suggestions from others as well. My thinking is to use 1" pipe insulation where possible, and in the areas where you can't fit it in because it's too close to the ceiling, just use half the insulation tube and use wire to attach it. Most of the heat will still be lost from the top of the pipe, but it's better than nothing. I've also considered using UT SolaFlex by Armacell. It's an elastomeric foam that's supposed to be good to 300 F.

https://armacell.us/products/utsolaflex/

I've used Knauf pipe insulation for the rest so far.

https://knaufnorthamerica.com/en-us/products/pipe-insulation

random12345

Another thought I just had would be to use some kind of metal pipe cover like this: https://insight-security.com/anti-climb-downpipe-cover-galvanised. Then just put a layer of fiberglass into it and screw/nail the box into the ceiling. Seal the edges of the cover with caulking.

EBEBRATT-Ed

Insulate where you can with 1" insulation. Use fiberglass. Do not use Armaflex it will not last.

The area the insulation won't fit around the pipe you could build a three-sided box around it and stuff it with insulation. You could use wood or the cover @random12345 suggested

reggi

As suggested already... though the some of the pipe appears to have pieces of insulation laying on top of them and once removed may give you enough clearance for the 1"fiberglass... What's the ceiling material? Concrete?

EdTheHeaterMan

Insulation is easy. just slap it on and cover it up. How nice do you need it to look? since there is a piece of Insulated Flex Duct there, then I might suggest the you need it to look at least that nice. But, just adding insulation to that pipe might not get your other problem resolved.

The house has a one-pipe steam system. It was built in 1924 and the garage and sunroom above were added in 1929. The radiators in the sunroom are not getting hot, and the previous owners installed an in-wall electric heater. The system works fine for the rest of the house; heats evenly, runs quietly, etc.

Seems like you might want to find out why that sun room radiator is not heating BEFORE you cover everything up with insulation. Let's consider a few things. After that pipe gets buried in the ceiling, there might be a vent at the end of that main (or feed) before it turns up into the sunroom. The pipe may also not have the proper pitch the drain the condensate properly. The vent on the actual radiator may be the only vent on that branch and therefore not fast enough to get all the air out of the pipe and radiator. (everybody with steam already knows that Air and Steam does not mix). If you don't get the air out the radiator wont get hot.

JH3550

Thank you, everyone, for your suggestions!

Ceiling is concrete.

I hadn't thought about the vent being part of the issue. I'll take a look at what's there.

JH3550

Here are pictures of the two radiators. Looks like the vent is mounted in a different spot on each one. (We haven't moved in, yet, so this is the best I have right now):

bburd

The upper vent hole is for hot water. The lower hole is for steam. When using steam, if the vent is in the upper hole the radiator will probably not heat fully.

ethicalpaul

You are not going to get much heat through that concrete to heat the room above. I'd forget that idea, but insulating the steam pipes will at least prevent you trying to heat your (presumably) cold garage.

Gsmith

Doesn't look like concrete, looks like mortar was troweled on to some unknown substrate. Might try removing a small piece somewhere to see what's under the mortar. Be careful and remove only a small piece, there could be asbestos board or other asbestos insulation under the mortar. But if its not something difficult to deal with like asbestos, then maybe removing the mortar just above the pipe area will allow you to put the insulation all around the pipe.

veteransteamhvac

As others have said, before you insulate, make sure the pitch is correct on all pipes. Since you're not yet moved in best to wait and see.

The garage ceiling pipes are an easy thing to insulate using either fiberglass, the round encased Owens Corning, or rubber EPDM. I don't get the hesitation to use rubber in interior spaces like this and especially in tight situations such as this. It's very flexible and easy to administer. The encased round fiberglass is very stiff and not flexible. I personally would just use 3/4" rubber here as you will be able to stuff it into those tight spots against the ceiling. For the parts that you cannot slip the top over the pipe towards the ceiling I would cut out the top 1/4 and use wire or tape to secure it in place.

Assuming the situation is that the garage ceiling pipes are simply condensing the feed steam to these convectors (after you've replaced those old vents) you really should not stop at just insulating the pipes in the garage. Insulating the pipes all the way back to the header will give the steam a much better fighting chance of making it all the way out there.

JH3550

Thank you for all the advice!

The pipes are insulated in the basement by *something* that is wrapped in black duct tape (almost certainly asbestos, but encased). I’ll check the pitch and inspect the vents in addition to insulating the garage pipes. 

Is there a way to tell if the vents are worn out other than the fact that the radiator is getting very warm? 

veteransteamhvac

Vents are limited life animals, and since you are new to the house a wholesale replacement of vents is prudent. Steam professionals will recommend the same for your boiler controls, LWCO and pressuretrol.

pedmec

Also might want to make sure the radiator valve is open. sounds obvious but every once and a while we get a call like that.

might just try 1" fsk duct wrap and just try and screw it to the ceiling around the exposed 1/2 pipe. Its hack but it will work

PRR

> if the vents are worn out
If you don't know, assume they are shot. They are not that expensive(?). The system will NOT heat if air does not vent.
Get Dan's Book(s)!!! https://heatinghelp.com/store/ (My goodness, he has been busy!) My first steam house I was clueless. My second steam house, I knew I was ignorant and it was costing big money so I read Holohan books front to back then back to front. Probably you want The Lost Art of Steam Heating Revisited (I guess I read the 1st edition). You might want We Got Steam Heat!: A Homeowner's Guide... first (it was not out when I needed it?). Yes you could buy bushels of coal for what these books cost; I assure you (my experience) you will more than make-up the book cost in fuel bills.
IMHO, the naked pipes are not your cold radiators. "Could be" for long runs, and especially short burner cycles, but steam was often specced for sleeping with windows open so there's capacity to heat the cellar, the garage, the crawlspace. Just adds to your fuel bill.
The system presumably worked once. The pipe pitch was OK then. Unless you see a lot of plaster/concrete cracking, assume the pitch hasn't changed much. (Yes, can't hurt to put a level on it. For long runs to large loads there's a spec; for a couple small convectors I'd think dead-level would heat, even if bangy. Which you do not report.)

Start with the books, compare to the living house. I think you will replace the air vents. I remember getting a big box mail-order (yes! that long ago!) and having 13 of 15 radiators HOT that night (big change from 5 hotties). As Dan will tell you, there's often a vent in cellar at the end of the main horizontal pipe. Mine was hard to get at, but when I did it, ALL the radiators heated.