Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Help!! staple-up insulation foil myth

wrooper Member Posts: 58
Hi all,

I have lurked here forever and used the info to design my own house's system.

I am selling a fixer-upper that has soft black pipe staple-up insulated below with R-19,paper faced,spaced 2".

The buyer's inspector is requesting replacement of the insulation [1700 sq ft] with foil faced and claiming 50% efficiency gains will result.

While I will allow that there may be some theoretical gain [5%?] I believe this is not cost effective.

Can anyone support me with their opinion? No liability,just an opinion based on what I have described.

Thanks in advance and my apologies to those I have contacted directly if you are repeating yourself      Bill


  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
    Foil Insulation

    Foil insulation is a fool's errand. While it will perform slightly better than non-foil initially, it is only a short amount of time till the foil gets dirty and dusty. When that happens it looses it's ability to reflect radiant heat and is no better than regular paper insulation.

  • wrooper
    wrooper Member Posts: 58
    Thanks Harvey

    Thanks Harvey,

    Can you mention your qualifications so I can use your statement with this inspector?
  • bill_105
    bill_105 Member Posts: 429
    50% improvement?

    Is he saying the fuel bills will drop that much? As long as the R-19 is installed nicely, not a chance.  

    Last time I checked a home inspectors job was to find defects.                               
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
    Mechanical Contracter

    I am just a lowly contractor with no letters after my name.

    In Radiant specifically,  I have been trained by Uponor, Taco, Viega, Dan Holohan, John Siggenthaler, Mark Eatherton, John Barba, either directly or indirectly. And lets not forget all the great people on the Wall, I have been trained by them to.

    I even have some certificates somewhere. I don't remember where though.

    Most Home Inspectors are bothersome people. I feel for you.
  • wrooper
    wrooper Member Posts: 58
    find defects?

    finding defects is fine,inventing defects is another story
  • Ironman
    Ironman Member Posts: 7,354
    edited February 2014

    Some, maybe most home inspectors do a good job. But then there are the ones that are real fountains of mis-information, like this one. Because they carry inspector credentials, home owners, and buyers, assume that what they say is gospel. I've been called out to houses more than once to have to refute some foolishness that a home inspector told potential buyers that was holding up a sale.

    Everything that Harvey told you is correct. The main issue is heat transfer plates, not foil-backed insulation. With out plates, the heat output of the floor will be less than half of that with plates. But even that doesn't settle the matter. The real question is: does the floor, and any supplemental heat source, produce enough heat output to match the heat loss of the house at design temperature?

    For what it's worth: I have 40+ years experience, several masters licenses and own a business that designs, installs and services radiant systems. I carry a class "A" Virginia license.

    Ask the inspector where he got his radiant training and faulty info.

    I get real tired of people spouting off info that they haven't researched and confirmed by a recognized authority.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • wrooper
    wrooper Member Posts: 58
    Thanks Bob

    Thanks Bob,

    This house does not have plates,IDK if they are/were available for Onix? tube in 2004. The house does seem to have enough radiation to heat. I have had it up to 72 degrees back in December.

     I'm sure the inspector was swayed by the fact that the thermostat was set at 45 degrees and here in upstate NY this house [log construction] was seriously "cold soaked" after 2 months. He walked in and turned the boiler on and was surprised? that the house was only warming by 1 degree per hour in the 3 hours he was there.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    For the real low down...

    Go to industry friend Robert Beans web site at www.healthyheating.com

    He has a whole section on reflective radiant barrier insulation.

    Everything the previous responders have said is correct.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Rich_49
    Rich_49 Member Posts: 2,766
    R Value

    is R value . If R 19 has a paper , foil , encapsulated it is still R 19 .  Ask your home inspector to go into a closet with no light and a mirror , then ask him what he sees .  Bet he sees nothing because you can only reflect light and the last time I checked there was not much of that commodity within a ceiling , floor or wall cavity .  Here are some letters for you if it helps . I'll send them in a PM because I think it's obnoxious
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • SWEI
    SWEI Member Posts: 7,356
    Plates for Onix

    Call Watts Radiant and ask them what's compatible.  I suspect their new FlexPlate might have been made for it.  It's also possible that some U-plates will work.
  • wrooper
    wrooper Member Posts: 58
    Healthy Heating foil

    Thanks Mark,

    I have looked at Healthy Heating but did not think it was on point. They talk a lot about the uselessness of putting "bubble foil" under slabs. I think it is pretty well established that "bubble foil" is a scam,particularly when they claim values in the range of R-30 per inch.

    I am worried that my inspector will respond with the several internet radiant sites that recommend foil faced fiberglass under their DIY staple-up.

    As I mentioned in my first post,I believe there may be some theoretical/short term advantage to foil faced batts but want to establish the futility of removing kraft face to replace with foil face.

    BTW I email bombed you on another address I found on-line,sorry Bill
    PLUMMER Member Posts: 42
    Double trouble with the foil bubble

    If I remember correctly that's what the article was called. Written by a formerly mentioned hydronics ME. Foil bubble miracle claims are the cause of many failed projects. I would specifically request which foil product he's referring to, then request the pertinent ASTM, HUD specs for his product of choice. Usually it doesn't go any further, because even R-13 will exceed the 3.5R value of a single layer with an enclosed & required 6" air space of the trouble bubble, including the Radiant gain claim of the foil. Don't let him use the stated percentage of radiant gain, but make him stick to an actual R value. Unless he's stubborn or has ulterior motives, he will quickly see the light you have bestowed upon him. Some fancy bubble products make several layers or wraps of the bubble and add the R values up. This couldn't be further from the reality. Each layer requires its own 6" of up disturbed and sealed air space to be able to add the R value. Bubble foil itself has almost NO R value, it's the sealed air space that makes the 1.7-3.6 R value. Several well documented articles and tests on this. Digging for them is sometimes hard, cause the foil market has done a lot of work, let's call it. Even a few of the article authors have been threatened with lawsuits. The key is ASTM approvals and ratings info.
  • wrooper
    wrooper Member Posts: 58
    bubble foil distraction

    sorry if I was unclear

    This is not a discussion of the "bubble foil" scam.

    The inspector is requesting removing kraft faced batts and replacing with foil faced batts.

    My point is just that this is folly

    Thanks for all the replies
  • I Concur

    WIth my colleagues, I have done it both ways and foil doesn't seem to make a difference. You should be able to get this info written down in Uponor's Literature.

    Thanks, Bob Gagnon
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Zman
    Zman Member Posts: 7,553
    Burden of proof

    I would simply ask the buyers inspector to provide any evidence to support his claim.

    Obviously the evidence would have to come from a third party agency, not the manufacture. He can't. It is his misinformed opinion.

    You could get the system up to temp on a cold day and ask him to verify the performance.

    If you have to satisfy the buyer to get this done. You can buy the foil and apply it to the insulation with 3M spay adhesive. Not a great job, but easier than hauling all the insulation out and buying new.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • CMadatMe
    CMadatMe Member Posts: 3,086

    R-Value is a radiant floors best friend. Like others have said R-19 is R-19 no matter the type. Sound like you have Onix tubing. The simple thing to do is to pull the installation manual and provide them with the manufactures insulation requirement.. If its installed with the minimum insulation as described by the manual then let them pay for it..
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Been there, seen that, done that....


    I am not sure what the current I+O manual for your tubing states, but many years ago, they did require the use of aluminum faced insulation. As others have stated, in order to get optimum radiant reflection, the reflective material must be 99.9% pure, should have a perfectly smooth face free of dust and other things that will affect its spectral reflectivity, and should have 1" of dead air space on either side of the reflective foil.

    If ALL of these parameters can't be met, then it won't work as expected.

    I was told by an insulation supplier that foil faced insulation is no longer manufactured .

    I have been to rubber hose staple up jobs that were severely underperforming. Upon arrival, we discovered that the required 2" air gap between the insulation face and the sub floor were not maintained when insulation was installed . All we did was go through the house crawl space and pull the insulation down, giving the required air gap, and the home finally became comfortable. We turned the operating temperature down from the 180 setting it had been at for 10 years. We lowered it to 150 and the place stayed very comfortable.

    I am a recognized expert witness in Colorado and the Federal court system. I am also a licensed Master plumber in Colorado. I've been doing what I do (Hydronics) for 37 years, soon to be 38.

    What are the qualification and credentials of your home inspector? How many years was he required to work in the field before he was able to hang his shingle? How many actual hydronic installations has he physically performed?

    DO NOT replace your insulation with foil faced or bubble foil bubble insulation. So long as you have the requisite 2" air gap, you are fine.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Gordy
    Gordy Member Posts: 9,546
    Foil faced insulation batts

    The only thing foil faced batts verses kraft faced batts are DESIGNED to do is provide greater vapor transmission resisitance, and elevate fire retarding. Not reflect radiant heat.

    In reading your post he is trying to do niether with his recommendation.

    Plenty of Ammo here to give the inspector.
  • jonny88
    jonny88 Member Posts: 1,139
    Letters after name

    if i refer to dans book correctly Ramer phd tld mat

    plumbing heating designer these letters dont mean a thing.

    I enjoy reading your comments and advice,Thanks
  • wrooper
    wrooper Member Posts: 58
    It gets worse

    Thanks for all your replies

    Now the buyer [not inspector] is saying that the return water temperature has caused unseen damage to the boiler! [Weil Mclain CGS]

    What happened was the buyer and his inspector showed up at the house during the polar vortex and I had the thermostat set at 45 degrees to save propane [I feared the talk of shortages] I had been ,most days,going there and firing the woodstove.

    They adjust the thermostat up and apparently the buyer observed the return temperatures to be less than 130 degrees as the manual calls for and now he is claiming this as a defect. BTW this system was not installed by me,does have boiler bypass piping and has been in operation for 10 years.

    I give up. He apparently does not get "cold start" or "steady state at design temperature".

    Looking at the manual there are many warnings about low return temperatures but does not give any caveats about taking these readings at operating temperatures or allowing system to reach steady state. Talk about just enough information to be dangerous!!
  • Ironman
    Ironman Member Posts: 7,354
    Return temp

    What controls the supply temp to the floor? Is there any provision for boiler protection?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • wrooper
    wrooper Member Posts: 58
    boiler protection

    boiler bypass piping

    My point is that buyer is looking at return temps when a cold start boiler is starting

    My understanding id that as long as return temps exceed 140 at some point during a call for heat then condensation is burned away
  • wrooper
    wrooper Member Posts: 58
    supply temp to floor

    sorry, forgot,supply temp is controlled by taco mixing valves
  • Gordy
    Gordy Member Posts: 9,546
    I will say

    That this home inspector is being thorough good for the buyer.

    Last year a friend of mine bought a log home with all kinds of trouble......and had a home inspection for 400 bucks. When i asked what the home inspector said about the issues in all facets plumbing, structural, electrical .... My friend said all the inspector said is this house will be a lot of work.

    About the low boiler return temp boiler shock would be what the inspector may suspect. If in deed there has been thermal stress over the last 10 years it would be leaking by now.

    Simple boiler bypass does not always guarantee protection through out a heat call.

    I have a WM Cgm 7 that's been drinking 95* return water from my radiant for 21 years simple boiler bypass installed.. Reasons of survival rate can be attributed to a generously oversized boiler. But as far as condensing its a non issue as boiler is always above 135 after heat call.

    Incidentally I have been hoping this thing would die so I can mod/con it. I hate pulling a perfectly good unit out to install a new one. That's why I have not worried about the return temp for the last 13 years I have had possession of the castle. Alias it lives on.
  • wrooper
    wrooper Member Posts: 58
    boiler shock?

    Thanks but I think you may be over your head

    Boiler shock comes from returning cold water to a hot boiler. A potential problem for a boiler that is running at 180 degrees 24/7.

    If you read my post you will see that a boiler coming up to heat was being returned water at some temp less than 130 degrees

    I would suppose that cooler water might cause some condensation before the boiler reached operating temp but "thermal shock" ,if occurring,would cause a problem before 10 years went by
  • Gordy
    Gordy Member Posts: 9,546
    edited March 2014
    Thermal shock

    Not over my head. Depends on how your system is set up. Staple up is what you have. What temps are you supplying? Is it zoned? Usually it happens when a certain zone is turned down to bare bones and the boiler is up to temp maybe coming off a call from another zone. Boiler is hot cold zone calls, and bingo bypass piping only helps a little.

    So the boiler can be a cold start boiler, and still get thermal shock in certain scenarios

    If your boiler is suffering from excessive condensing then there will be metal flakes in the pan below the burners, and on the burner tubes. Don't know your service regime annually or otherwise. Has it been serviced periodically?

    If your boiler is plumbed according to WM I/O manual then point that out to the buyer, and inspector. If not they may have a point.
    PLUMMER Member Posts: 42
    Wow, inspector knowledge limited

    I would combat that with a professional in the trade to come out and hold the adult inspectors hand while explaining to the lack luster unknowledgable inspector about how these systems operate. Then give him an invoice for the education that he will continue to use for his job. If the inspector was really "good" you wouldn't be posting here. During the -9 temps last nite and this morning my 24 year old burn ham hasn't got above 138 in the last 12-14 hours. Not one sign of condensation, no rusty flakes, no drips and sizzles under sustained low temps. It's running at 112-126 with occasional peaks. Dust bunnies are more of a problem. It doesn't always run like this but it did last night since the ODR was turned to -20 or 30 instead of +20.

    It sounds like inspector/buyer is looking for something to knock price down, rather than being thorough. I usually see code violations corrected not this nit picky un knowledgable requests. Good luck either way. And these real trade professionals have plenty of EXCELLENT info for you.
  • Gordy
    Gordy Member Posts: 9,546
    Praying on the housing market

    Plummer is right. Next they will want window replacements. Triple glazed krypton filled please.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    I agree...

    Everyone is looking for a "good deal"… It's human nature, but it shouldn't happen at your expense.

    I think your assessment is correct in that they showed up to a totally cold house, and what they saw was perfectly normal.

    For the record, EVERY boiler condenses when it is first started. It is the long term condensing that causes issues, and the signs are REAL obvious. Fur growing around all of the flue pipe joints, rust falling out of the draft diverter and as others have said, onto the burner assembly.

    People hire home inspectors for two reasons. One is to find the obvious (have you ever seen the release caveats these guys put into their contractual agreement???) The other is to find something POTENTIALLY wrong, so that the buyer can justify knocking your price down.

    Unless you are extremely desperate, I'd tell this buyer that he is purchasing a working system "As is", and if he doesn't like it, let him walk. If he is REALLY worried about it, have him purchase a homeowners warranty plan (at his expense), like Blue Ribbon or one of the others on the market.

    My $0.02 worth. Keep the change :-)

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
    PLUMMER Member Posts: 42
    edited March 2014

    And I wish there was a LIKE tab here

    Good one Mark
  • wrooper
    wrooper Member Posts: 58
    thanks Mark

    Good one Mark,

    I don't know why I did not think to offer a home warranty. Will let you know how it goes. At this point I still don't know if this is "back door" price negotiation or first time buyer jitters.

    BTW I have supplied a link to this discussion to the buyer's realtor. Not sure if the buyer is reading along.
  • wrooper
    wrooper Member Posts: 58
    one more

    BTW, I think I figured out the buyer's claims about cold water returns. I initially misspoke but this boiler is piped with one pipe primary/secondary piping with the boiler in the primary loop.

    Unfortunately the buyer was looking at thermostats mounted in the supply/return of the secondary [loops] and saw LOOP return temperatures,which,of course, were very low especially at startup.

    I will let you know what happens
  • Plummer

    Is right about the like button, if we saw a reply had many likes we would know that it is likely the correct answer.

    Thanks, Bob Gagnon
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • wrooper
    wrooper Member Posts: 58
    Sale fail

    The buyer finally walked. I can't help but believe that it [and all the claims/issues] was just first time buyer jitters. Apparently the wife made the comment to their agent that the house "needed $20k of repairs/upgrades"

    Funny because when I am flipping the big selling point for me [in upstate NY with old housing stock] is that my houses need nothing which is unusual here.

    At least I kept the earnest money

    Thanks for your attention   Bill
  • wrooper
    wrooper Member Posts: 58
    I forgot to mention

    I spoke with an engineer at Watts/Onix who said he cringed when he read their install manual claiming "25% improvement" using foil faced insulation.

    He agreed to send me an email disclaiming this. 5 minutes later he called me back and said his mgr would not let him make any statements that contradicted the manual.

    Speaking with multiple installers etc in this area,most were making claims about the advantages of foil faced insulation in radiant applications.

    Apparently once something hits the literature it stays.........
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    True statement...

    The problem is, that the ideal conditions, as previously presented, will NOT be present in short order. Once dust gets onto the aluminum, it is virtually useless, and that generally happens within the first year.

    Take your wife out to dinner on the earnest money :-)

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.