Pipe insulation, what you should know

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Hairyhosebib, Aug 22, 2010.

  1. Hairyhosebib

    Hairyhosebib New Member

    Messages:
    173
    Location:
    Arizona
    I would like to make an attempt at sharing some information about pipe insulation. Hopefully I will be able to post some pics of how to make fitting covers and install insulation properly. I have 30+ years of plumbing, drain cleaning and pipe insulation experience at two University/research settings.
    Is pipe insulation important? Yes it is. Most people only recognize it's importance in saving money by keeping plumbing systems to a particular temperature. It is also used as a sound deadening on drains. To the average homeowner it should mean another way to stop mold from growing in those dark , quiet covered places where nobody ever looks. Mold can be very dangerous and cause health problems for you , kids and pets. Condensation or sweating pipes is common and is just asking for mold to grow where there is moisture. If it can help stop this, then it's price and time is well worth it's price.
    Another thing about pipe insulation that really seems to bother people is what happens if it catches fire? I can certainly tell you, the last thing I'm going to worry about when my house is burning down around my ears is how toxic the fumes are that are being produced by a few feet of burning pipe insulation. Take a look around your home. Pretty much everything you have in your home could be made from some man made material that will burn. A huge number of items are made from plastic which is derived from oil. When it burns, IT'S TOXIC!! Isn't it nice to know that our government cares that we don't die from toxic smoke from pipe insulation but we can from other items?
    For the typical homeowner I suggest using the Armaflex ARMACELL foam pipe insulation with a minimum 1/2" wall thickness. I see Home Depot sells it in a 3/8" thick wall that is pre split with the tape. I would steer clear of this and seek out a plumbing supply house that sells the solid tubes. You will need to buy the Armaflex 520 adhesive too. You will learn to cut angles with a knife so it is better to handle when the wall thickness is 1/2" and not already split open.
    You only need some simple tools and the adhesive to do a nice job with little practice that I will share.

    1. Knife= I use a hacksaw blade that I sharpen down on the back edge to a point. It will need to be pointed. I would not use a utility knife, you need something with some length to it. Also this material will dull a knife blade quickly. A hacksaw blade does a great job when roughed up with a good file. Saw blades are cheap too. You could use a steak knife but you will need to keep it roughed up. You could use the teeth of the saw blade but the edge will be rough, you still need a point to stick in the insulation to cut circles.

    2. Ruler

    3. compass? It's one of those drafting tools that makes circles. I have been referring to it as the fancy circle maker for so long, I really don't remember what you call it. It has a needle on one side and a pencil on the other to draw circles.

    4. rags

    5. WD40= to put on the rag to clean the adhesive from wherever it gets on that you don't want it on.

    6. Adhesive = to glue pieces together with. You will put a thin film of the glue on each surface, wait a minute and join the pieces together. OH! it's toxic and very flammable too!

    7. gloves= optional. cotton, not rubber. Glue will eat the rubber. I personally don't use them for this.

    8. glue gun and brush= an optional tool if you have a lot of insulation to put on. A seriously cool tool sold by MCMASTER CARR. Basically, it's a pump type oil can with a really nice brush that screws on. A REAL TIME AND GLUE SAVER! It is made by PLEWS TOOLS.

    9. Narrow pieces of wood , they could be 1" inch long and 1/2" square. A hardwood is best. You will need these where pipe is hung with pipe strap, ETC.

    10. Some good duct tape. You will need this for covering the piece of wood where you have cut a small rectangle and glued in the piece of wood to support the weight of the pipe with water in it so it does not flatten the insulation on the underside of the pipe.


    If you are building or remodeling a home you will need to make the holes for your pipes at least 1" inch bigger than the pipe and 2" would be better. Make certain that you have plenty of room between the pipes to make the insulation fit around the pipe without it getting squeezed or pinched. Be sure to take in account for extra room of valves and unions too. Squeezing, pinching and tie wraps are big NO NO's If the outer skin is damaged, coat it with the glue or paint it with glossy water borne paint to identify if it is a hot or cold pipe.
    If you are going through a floor, you may want to take a piece of rolled metal or bigger pipe and put in the hole to sleeve it first. Then install your pipe, then the insulation. As you install the piping system you can cut pieces a couple inches shorter and slide over the pipe as you go. Take great care not to damage the inner or outer skin. keep the unused sections in a safe place to avoid damage. If a piece of pipe or metal gets laid across it, it will get permanently squished down. Cut out and discard areas that get squished or poked. I am in no way affiliated with the Armacell company. I am doing this on my own for your information.


    MORE LATER
    Last edited: Aug 24, 2010
  2. jch

    jch New Member

    Are you only referring to water supply pipes?

    Or is there foam insulation that fits 3" or 4" ABS drain pipes too (to deaden the sound)?

    Thanks!
    .../j
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,815
    Location:
    Cave Creek, Arizona
    quote; I see Home Depot sells it in a 3/8" thick wall that is pre split with the tape. I would steer clear of this and seek out a plumbing supply house that sells the solid tubes. You will need to buy the Armaflex 520 adhesive too. You will learn to cut angles with a knife so it is better to handle when the wall thickness is 1/2" and not already split open.

    If the piping is already installed, then the presplit insulation is preferable, since all you have to do is peel off the plastic strip and press it together. If you are using solid tubes, why would you need the adhesive? When I use Armorflex, I slide it around the corners rather than miter the insulation.
  4. Hairyhosebib

    Hairyhosebib New Member

    Messages:
    173
    Location:
    Arizona
    Yes, I am mostly referring to water supply lines. I have insulated drain lines to cut down on the sound of water running through a drain in office areas where restrooms are on the floor above. Some haughty taughty professors just don't like to hear water running when they are trying to think hard. Drainlines can also condensate , drip and ruin ceiling tiles and invite mold to grow. Holes in floors and walls where waterlines and drains go through can get pretty ugly too.

    pushing the insulation around fittings is a huge NO NO!! You are causing it to be pinched on the inner part of the elbow and cause stress and stretching on the back side as well. You will also damage the inner skin of the tube. You do make a point I forgot to mention. As you are installing your piping system you can cut lengths that are shorter than the pipe to save time and glue, just slide it over the ends of your pipe being careful not to tear the inside skin. Once the installation is complete you can do a leak check and then finish the insulation work. I make elbows out of four pieces. It's about a 30 or 33 degree angle. I have been doing it that way so long they just pretty much come out in a perfect 90 degree. Even if you don't get them perfect you can still have room to fudge it and they will still look good too. You will need the glue in order to cut the miters. You could use household contact cement but the 520 is a better product. Armaflex may still sell tubes that you slide the insulation through and then cut the miter joints. They make the 90's out of two pieces, I think they look ugly with that big squared end sticking out. You also have to cut more accurately too. Armaflex can be purchased in several large diameters and wall thicknesses. They also make it in a 3' by 4' sheet in several thicknesses. They also used to offer a package of templates to lay on the sheet to cut out for big piping jobs. I used to have a set that I had transferred to 1/4" plywood with the size written on them and a nice wood finish too. I had left them in my barn in Indiana and the guy I rented the house to when we moved to AZ burned down the barn! The problem with insulation foam tubing is there is no directions on how to properly install it. Most people take it home and force it around the pipe and slob it up with duct tape. I have seen contractors come on campus and do the same thing. It's just ugly and disgraceful!
    In Indiana there are M E N A R D S stores that actually carry a premade elbow and tee, ETC fittings. You may want to check that out. They may be the harder foam stuff that I am not a real fan of. It may just be a silly preference thing. I do prefer the Armacell. There is another company that makes a similar product but is slightly more dense and stinks bad. The name escapes me though. This type of insulation is a great product but at the same time it is very delicate to install properly. Pipe insulation is an art form in of itself. Union insulaters sometimes make more than a union plumber or steamfitter. You really have to know a lot of math when doing big insulation work. Pretty much the same as a sheet metal guy. The other brand is RUBATEX.
    Last edited: Aug 22, 2010
  5. Kimster

    Kimster New Member

    Messages:
    87
    Location:
    Manitoba
    I'm assuming you're referring to copper or other metal pipes. What about insulation for Pex? Should you and with what?

    TIA!
  6. Hairyhosebib

    Hairyhosebib New Member

    Messages:
    173
    Location:
    Arizona
    It could have the potential to condensate, I would insulate it. I would use the armaflex on it too. If you are using the expansion method or sharkbite fittings you will butt the end of the tube against the fitting and make a cover from a piece of insulation tube that will fit over it. The diameter is easy to make bigger with little effort. I will soon take some pics and post. I will be taking pics by myself so it might be a little harder to show without help.
  7. Hairyhosebib

    Hairyhosebib New Member

    Messages:
    173
    Location:
    Arizona
    Taking measurements might seem unimportant. Measurements are taken from END to CENTER, CENTER to CENTER and END to END. This refers to the bottom pic.


    [​IMG]


    The pictures seem to be getting jumbled. Here is a photo of pieces that I cut, one that I have glued together and one that has been cut into two pieces to show consistency of wall thickness around the entire 1/2 " copper elbow. You won't get this when the insulation is forced around a elbow or when the pre slit stuff is forced around the diameter of the pipe. KNIT PICKER NOTE: OK, so they are not perfect 90's. I have not made any of these for awhile, I'm a little out of tune. It's nice that this product can have some room to cheat.
    There is the hacksaw blade that I grind down on it's back edge to a point. A file can be used to keep the edge roughed up. It is crude but they are cheap and expendable. If you lose it in your attic or wherever you can barely fit in while working on the insulation it will be easy to replace.
    I'm not even going to try to convince anybody this is a fun job. When I worked at Purdue, I volunteered to be the insulator. There are plenty of times that holes were not big enough to accommodate the insulation or pipes were too close together because of space or worse yet, trying to put insulation around a pipe with one hand while trying to steady myself in an awkward position. Normally the plumber was responsible for doing their own insulation work. The insulator job was born out of politics and when the old boss retired, that job did too. It only lasted about three years. Then I was back out doing plumbing and the insulation too like everybody else.
    I'm really interested in guiding you through a job that you know will get done to the best of your ability. You can have the most beautiful pipe installation in the world but when you do a sloppy job with the insulation, this is what everybody sees and you pretty much have to judge the job by the cover. If you paint it to color code it, it will make what looks bad bare even worse!
    The other nice thing about a elbow like this is it can be cut open from the front, back or either side in order to put it on the pipe. You won't always get a good 360 degree view of the work. Be sure the pipe is wiped clean of flux residue and moisture before putting it on. Also be aware of solder drips hanging off of fittings that might be unseen, they might cut you.
    While I'm thinking about, I would like to say that a ball valve has got to be the hardest thing to put insulation on and still look decent. I have seen jobs where a ball valve extension handle is put on to raise the handle. They are expensive but do help quite a bit. They are hard to find too.
    If you have a water line with a heat tape taped on, naturally you will want a larger size insulation. This product is not fond of being stretched.

    Attached Files:

    Last edited: Aug 24, 2010
  8. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Best tool in my box is a 1$ serrated bread knife from the dollar store.
  9. Hairyhosebib

    Hairyhosebib New Member

    Messages:
    173
    Location:
    Arizona
    Yes, That would probably do the trick as long as it goes down to a point to pierce the insulation to make small holes to wrap around tees and valves, etc. You also need it to be narrow in order to cut fish mouths in when butting up to a branch in the line.
  10. Kimster

    Kimster New Member

    Messages:
    87
    Location:
    Manitoba
    Wow, that's pretty nice. I've never seen anything like this. You're obviously someone who takes their trade seriously. What do you do for tees?
  11. Hairyhosebib

    Hairyhosebib New Member

    Messages:
    173
    Location:
    Arizona
    [​IMG]

    Tees are pretty simple. Measure your center line to your end or use a random length. You can take your fancy circle maker and scratch an outline in the skin as a guide for you to cut at. This will be important if you are doing large pipe jobs. You can also just free hand a hole. That is what I did here. If they look ugly or are a little big , it is of no matter. I free handed this fish mouth cut, I have made nicer and I have made worse. Again, this type of insulation can be forgiving and can be fudged a good bit. Big box stores sell a gray colored insulation that is much firmer than the Armacell and greater care will need to be used. You are simply contour fitting the cut pieces together like a puzzle. Could be a great activity for a little kid.. Just for fun you could figure a scale to make sure the letters are the same size and cut all the angles to spell your name.
    I cut the circle first. Then I cut it through it's length. Then I cut it from the edge of the circle to the length cut. I do not ever cut it through the center of the circle at it's length. It's hard to explain, but it takes strength away from the insulation. They are really hard to glue and need a lot of baby sitting. The first part I glue together is the area from the edge of the hole to the length cut. Then I glue the length. I will glue the fish mouth part at it's length then the fish mouth part to the other part.. I'm sure a video would be more helpful here.
    Yes, I do take this job seriously. It is the final part of the plumbing process with the exception of painting You know how hard you worked on installing the pipe and I know it is no fun trying to fit yourself in tight places so you won't have to pay somebody big bucks to do it for you. Now you are putting the insulation on to protect the pipe and everything around it to avoid heat loss, condensation, mold, bugs, etc.
    Last edited: Aug 25, 2010
  12. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    I didn't know that insulating pipe was complicated enough to require explanation...
  13. Hairyhosebib

    Hairyhosebib New Member

    Messages:
    173
    Location:
    Arizona
    http://www.mcmaster.com/#adhesive-dispensers/=8knhh3

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    [​IMG]

    [​IMG]

    Here are some pics and a link about the handy dandy glue gun I mentioned earlier. You will need to get a small plastic dedicated container with a good sealing lid to put a used brush in. Spray enough WD-40 in the container to cover the brush or brushes in when they are not being used. The brush will last a long time when properly cared for. When you are ready to use a brush you will remove it from the container of WD-40 and laying the brush flat on a sturdy surface you will drag the tip of the knife through the bristles to pull out the old glue. When most of the glue is removed you can put the brush back on the glue gun and pump some fresh glue through into a rag. Take the rag squeezing and pulling the bristles to remove excess WD-40 and then you are ready to use the gun again. If the gun has set for awhile, just pump some glue through and use a rag to work the glue into the bristles to loosen them up again. The gun is pretty easy to take apart and clean. The brushes are of very good quality. You can bend a wire to put through the hole of the used brush to help retrieve it from the container with the WD-40 in it. If you are in the handyman business this will be a real time and glue saving tool.
    Last edited: Aug 26, 2010
  14. Hairyhosebib

    Hairyhosebib New Member

    Messages:
    173
    Location:
    Arizona
    [​IMG]

    [​IMG]

    Supporting the pipe insulation in hangers or resting on any surface is important to maintain it's shape and integrity. The weight of the pipe and fluid within will cause it to become flat on the bottom. I found this nice piece of maple wood perfect for this lesson. I cut them into 1" long pieces. You can gently press the block to the skin of the insulation and it will make an outline that you can then cut out the rectangle. Next glue the piece of wood in the hole. Put a little bit of duct tape over the block because I said too. Then place it on a piece of bent metal to help protect the skin. The hanger is a clevis hanger, not typical for the home. Whatever hanger you have, make certain you are not squeezing the insulation down to hang it. If you are using unistrut and the clamps, insulate the inside of the channel as best you can and then cover over the clamp . I have seen insulation squeezed down with the clamp or insulation butted up against the channel and what is in between is not insulated at all, you are inviting problems.
    Last edited: Aug 26, 2010
  15. sapper12B

    sapper12B New Member

    Messages:
    1
    Location:
    Florida
    Great information on pipe insulation

    Many moons ago , I was a pipe insulator by trade, although I worked mostly with Cal-sil and mineral wool ( nasty stuff ) I had a chance to work with rubber ( A-flex) We used to get it large rools which was great if you could just slide it on the pipefor straight runs. Thanks for the great info . I have to insulate my well room due to sweating. Im not sure if I can mention a website, but I was able to buy a nice rubber knife and glue gun from a site called www.respiratorpartsplus.com. I searched for glue gun, and I found it, also found a great knife. Thanks again for the great info!
  16. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,815
    Location:
    Cave Creek, Arizona
    If I need pipes insulated to that extent, I hire an insulation contractor. THey work a lot cheaper than I do.
  17. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Any hobo will tell you that newspaper makes great insulation. I Insulated all my pipes in the first shack I built with papers rolled around a mandrel and taped with duct tape. CHEAP in the extreme, and its still there and never had a pipe freeze.

    Corners? Your old underwear and socks and more duct tape.

    Its called Eco-insulation.
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