HOW TO SECURE & INSULATE PIPES BEHIND WALLS

hankwylerjr

Im in the middle of running new 1 1/2 black pipe along with hot and cold water, 3 inch sewer pipe from my basement to the attic to a new addition. I have this beautiful chase behind my shower wall that is probably the best way to go so we dont see all these ugly pipes. Question, how do I secure (meaning strap them to the wall etc) and tighten the black pipe with a coupler or union in that wall cavity? (I have two 5 foot pieces to join because of the space couldn't run a 10 or 8 foot up or down because of space restraints) Its only about 12 inches wide I dont want to open up the entire wall of my bathroom. Can I manually tighten them by hand put a pipe wrench in the attic at the top of the run and go downstairs and put the other on and turn? Its only me doing it. Also want to make these pipes quiet dont want them to bang or make noise if at all possible. I mean I can probably jam insulation around them after I wrap them with fiberglass insulation to maintain the heat going upstairs.

ratio

I think I'd try to do it all from below, insulate a section (cover the pipe with a [loose] cap or tape!), push that up, add another section, insulate, push that up, lather, repeat. If it's insulated, it shouldn't make much noise. If it's only ≈10' or so I wouldn't worry about strapping it in the wall either.

Jamie Hall

These are steam pipes? I'd assemble them as @ratio suggests. As to anchoring them -- they should be anchored firmly -- up down and sideways -- at one end (top or bottom, doesn't matter), but at the other end they should be anchored to they can move lengthwise (though not horizontally) freely. Any intermediate supports likewise -- the pipe must be free to slide easily up and down. Otherwise you will have expansion noises and you will be annoyed...

hankwylerjr

@Jamie Hall yes the black pipe we were talking about. What should I use? Do they sell special straps? I'll feed 1 5 foot piece up through the basement ceiling into the chase. The other piece I was going to run from the attic floor but your saying everything up from the basement? I'm using a coupler to join them. To tighten them however within that wall chase will be challenging unless like I said, tighten them like I described. I'll never fit my wrenches in that chase

Jamie Hall

Once you can fit a five foot piece up the chase, is there enough play to put the next five foot piece on and tighten it in the basement and feed that up? Or is the geometry such that that won't work? I'm envisioning putting one five foot piece up the chase, and than threading on a coupling and another five foot piece -- still from the basement -- and pushing the whole string up. However, if that won't work, do you have five feet headroom on the second floor? If so, lower the first five foot piece down and thread a coupling and the second five foot piece on and lower the whole assembly the rest of the way. If you don't have a five foot straight shot on either end... got a problem. You may have to use more, shorter pieces and more couplings, which could get tedious. In any event, I would not use a union anywhere on the string. I'd use couplings, and thread them up tight before they got pushed up (or down) into the chase.

I have a notion that the 3 inch DWV is going to be even more of a challenge... and I'd use PEX for the hot and cold water lines, You can try pushing the PEX, but you might have better luck dropping an electrician's fish tape down the chase once the other pipes are in and pulling the PEX back up with it.

I'm honestly not sure how I'd anchor the two black iron pipes -- they're the ones you need to worry about. That's the kind of thing I tend to stand and look at for a while and think about. And usually end up with some sort of creative Rube Goldberg arrangement...

ratio

Like @Jamie Hall said, smaller pieces if you can't get on the ends of the 5' pieces. Just be sure to make them up leak-free, it'd be a bear to find & fix a leak once the run's in the wall!

JUGHNE

Be sure to use real couplings.....not the "Merchant" ones that come with a length of pipe....those have no taper inside and could be a leaker.

I would maybe use good hangers on rods on the horizontal pipes in the basement. Just have them close to the 90 where it goes vertical. For the top of the chase, perhaps a piece of plywood with generous oversized holes drilled to allow for expansion of length with out being bound up by the wood. Rasp/file the holes to be as smooth as possible to avoid friction.

hankwylerjr

I just measured my basement floor to the ceiling. It is approx 8 feet 6 inches. So, with that being said Im wondering if I can squeeze a 10 foot piece (drill a much bigger hole to allow me to manipulate it at an angle straight up to the attic) now in the attic I only have about 3-4 feet because the roof comes down at an angle because its behind my knee wall. If I leave room for expansion I may need to use bulk insulation and just cram it in there because I will have two gaping holes one in basement one in attic. Let me be clear, there is plenty of room within the chase so i dot anticipate running the sewer line and PEX. My only major concern is was joining the two pipes for steam together within the chase wall. If I use some Blue Monster and really crank it tight I think that it wouldn't leak. If it does, I think that the boiler will tell me by looking at the gauge? Far as securing the pipes I think they will be done using standard 1 1/2 straps prob available at the big box stores. Im attaching what a 10 foot piece looks like at an angle running from my floor to the top of my ceiling. If the 10 wont work Ill have them cut it at 8? (I got rid of my pipe threader last year) plumbing supply will do it because i buy everything from them. The part that concerns me still @Jamie Hall is once I get this put together Im going to have issues most likely once the run is completed and I have my Tee in attic. From there we said we can run the 1 1/2 over to the larger rad and run a smaller line over to the very small rad. Im worried about this being pitched correctly so that its not bubbling and banging. Im working alone and taking my time

Jamie Hall

Sounds like you have a plan.. Bravo! It's always interesting...

At the top. The two radiators are in opposite directions (of course!) from where the riser comes up? At the top of the riser, use a T oriented at right angles to the direction the pipes to the readiators have to go. Use close nipples and a 90 to get the pipes headed in the right direction -- and that way you can set the pitch of the "horizontal" runouts to whatever you need.

hankwylerjr

@Jamie Hall lol just because I have a plan doesnt mean its going to work for me. If the 10 foot works it will be simple. If not maybe the 8 will get me to where I need to be in the attic. Ill revisit this when i finally get this run completed. Appreciate all the advice and help and dont be afraid to add to it anytime Il be working on this for a little while yet maybe in a week it should be one. The 90's will get me the right pitch Im assuming. I couldnt get the square plug off the main however. My plumber is coming over to cut a 3 foot section of the main and add a Tee for me to tie into. The plug was rounded absolutely nothing would break it free. Plus, I can get much closer to my riser by the NBP so that my run will get nice and toasty really quick :-) Plumber is backed up obviously if he cant come son Ill try to do it myself but dont want anything going wrong when its cold outside. I think that the Tees and elbows are malleable and I prob could smash em and just get a new length of pipe from the supplier add a union and ut it together myself (if iw was spring already Id tackle it myself)

STEVEusaPA

Keep in mind when your all done, those penetrations will need to be sealed. You don't want to create a nice fire chase from basement to second floor.

hankwylerjr

Yes, never thought about that. Maybe some type of fire block foam or caulking I'm thinking, ty

hankwylerjr

Question, can I run my 1 1/2 from one corner to another? See diagram. Otherwise, I'll be spending another 150 bucks on elbows nipple etc

dopey27177

Be sure you use a 3 elbow swing at the base of the riser. Additionally, that is the location to install the hanger support for the riser. 3 elbow swings should be used for the piping off the top of the riser, the swing joints will take care of expansion and contraction. Additionally make sure you allow for proper pitch to your new radiators.

Jake

hankwylerjr

@dopey27177 3 swing joint sounds tricky for my experience. Also this elbow in my sketch is actually a Tee see above comments and my original sketch. Any idea on how to put this together properly would be appreciated

EBEBRATT-Ed

@hankwylerjr
Use a riser clamp to support the pipes at the top of the run in the attic. You will probably have to go to a real plumbing supply and not the big box stores.....don't think they have them

Your probably going to have to install the pipe in 3 pieces instead of 2 unless you open up the wall. and use 2 couplings

JUGHNE

Hank, we talked about the swing joints previously.
And do not bull head the tee. Use the side branch of the tee for one rad and come off the top for the larger rad.

You should add those "extra" swing 90's to get the slope.
If I remember your project, it is border line for sizing and return slope for counter flow piping.

hankwylerjr

@EBEBRATT-Ed I successfully worked a solid 1 piece 10 foot from the basement to the attic this far I'll be back soon at son's game

hankwylerjr

@JUGHNE I had the opportunity to get an old steam head on the phone for a brief convo. He's disabled and retired. I told him my plans and my concerns about the EDR for my project. He simply chuckled, he further said that with that 1 1/2 run from the 2 inch I'd be "fine" and that I could comfortably squeeze out one or even two more rads and still have some left. He is a master plumber and has done mostly steam in NYC for over 50 years. I'll take a chance. If it doesn't work I'll replace the larger one with a smaller. It's staying where it is in the attic too heavy for me for 2 flights of stairs

hankwylerjr

I'm going to have problems with the assembly of this swing joint. I bought a box of elbows, nipple today. I understand about the rest for the most part and appreciate the help tremendously.

dopey27177

Here is some thing to be careful about and a different way to tie in your steam riser.

Taken from my book on seam heating

hankwylerjr

@dopey27177 looks like a good book

hot_rod

vertical piping is usually supported top, and maybe bottom with riser clamps, as Ed mentioned. Really nothing in the wall. Install pipe, with riser clamp up top, slide insulation on.

ethicalpaul

I think you’ll find that with the 3 90s it will actually be easier, not harder, to get things aligned. That was my experience with my recent repipe.

Try it dry in the open to see how it works

hankwylerjr

@ethicalpaul 3 90s with what size nipples?

hankwylerjr

My parts so far plus black pipe, besides pipe straps do I need anything else? @Jamie Hall

ethicalpaul

It depends. You can use the lengths that get your pipe where you want it to be. The “close” nipples are the shortest and the street elbows are even tighter.

You can see my solution in the posts in this thread: https://forum.heatinghelp.com/discussion/177777/autumn-saturday-radiator-repipe

hankwylerjr

Do I need 2 swing joints? One coming out the top of the tee for larger rad and one out the side for the smaller rad. What parts do I need exactly for the two swing joints any help much appreciated

ethicalpaul

Jake said above that he recommended that you put the swing joints on the top and the bottom, and I don't disagree. However, it all depends on your situation.

In my situation I linked above, I had a three piece in the basement, and not on the top. It depends on where you have to get to, and how much expansion/contraction you expect.

Each additional joint gives you another axis of motion and will require a nipple and an elbow. It's difficult to give precise instructions in a forum I'm afraid. Remember that people spend whole apprenticeships and in fact careers getting good at pipefitting!

hankwylerjr

@ethicalpaul I understand. I helped pipe-fitting as a teenager for extra money never made it as my trade changed. I have some knowledge and in fact have installed other rads in our rentals through two and three floors but they were failry straight runs however, swing joint is not something I had a lot of experience with unfortunate. Im going to my plumbing supply now Il tell them I need to make 2 swing joints and get all the parts. Ill dry fit everything today and maybe upload a picture of what I am working with Im certain Ill get some solid advice from y'all. I have no choice at this point the only plumber familiar with these steam one pipe systems is booked solid and for whatever reason isnt really motivated to come to my home soon. Seems like he has other works thats easier or where he can make more $$$. He did say he would do it but I cant simply wait until next month.

hankwylerjr

maybe I use 2 street elbows coming out of the Tee to make it easier?

Hap_Hazzard

You'll find that the street elbows can make it difficult to get the exact angles you want. When you screw a fitting onto a pipe, you can usually tighten it up to one full turn after it starts getting tight, but when you screw a street fitting into another fitting, it gets tight more suddenly because cast iron fittings are much harder than mild steel pipe.

hankwylerjr

For the very smaller rad can I use a reducer on the tee down to a 1 inch pipe? It's a 4 foot run. It would make it cheaper and probably easier to handle then running 1 1/2 to a tiny rad

Hap_Hazzard

It will also allow it to fill faster, because there will be less air to vent out. You can either use a reducer coupling or get a tee with two 1½" and one 1" fitting. They have all kinds of special tees at SupplyHouse.

hankwylerjr

@Hap_Hazzard I need a couple of 90s but I think that this setup (attached) would be sufficient providing I get the both runs to the rads at a good pitch?

Hap_Hazzard

Looks good to me.

hankwylerjr

What kind of pitch am I looking at with a approx 4 and 6 foot run for maximum return. I dont want or want to minimize any noises banging etc if at all possible? About to secure my 10 foot run vertically with the riser clamp and Im plumbing it up now. Once everything is secured Ill slide the pipe insulation up and fill the voids with foam or fire block caulking. I will then insulate all pipes behind my knee wall with fiberglass and loose insulation with some zip ties because Ill never see it so if dont have to look pretty.

Hap_Hazzard

Well, for maximum return it would be vertical. The minimum pitch is 1"/10ft for countercurrent flow and 1"/20ft for concurrent.

hankwylerjr

@Hap_Hazzard yes however no all vertical run in this scenario. If I can pitch the runs much more than that, 1 inch every 10 feet, I should be OK?

ethicalpaul

Yes

hankwylerjr

I'm using blue monster pipe dope and their brand Teflon like tape for the pipe joints. Is there anything better? Secondly, how tight am I supposed to get these swing and other joints and other connections? I understand that there will be movement with expansion and contraction?