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Insul-tarp

Who has used Insul-tarp. My cement contractor advised me that this is used on top of concrete not under it. He said that when you pour concrete on it it will billow up and have air pockets in it. Have any of your contractors have had this problem.

Comments



  • From what we've seen, Insultarp does not provide good R-value in underslab appilcations because it relies on the air pockets to provide insulation; under concrete, they don't stand up.
  • hr
    hr Member Posts: 6,106
    I use InsulTarp

    although I still prefer foam for the edge and vertical insulation. I agree it is not the same R value as 1" foam, but it sure seems to perform as well, and provides an excellent vapor barrier compared to foam sheet.

    InsulTarp does have some closed cell foam in addition to bubbles, also.

    I've been doing some testing with foam and Insultarp. I'll have details soon.

    hot rod

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  • Scott25
    Scott25 Member Posts: 30
    performance

    I have seen insultarp in action and am very impressed. Watched a 10,000 sq ft warehouse come up to temp from a cold start on a winter day in about 12 hours. AMAZING!


    I cant comment on billowing or air pockets because I have never seen that happen.


    Scott
  • Constantin
    Constantin Member Posts: 3,796
    Radiant Barriers

    ... usually work best in space, where there is no convection to worry about. On earth, I see their best application on the exterior walls, to keep the sun load out, and perhaps some of the interior load in. They may even work as a means of increasing the efficiency of a staple-up job, if they are supplemented by insulation behind them.

    However, below ground, they are little more than a thermal break, as far as I can tell. Glacier Bay manufacturers Vacuum Insulation Panels, items that offer a true R-50/inch but at a super premium price. Not to repeat myself too many times, but GB published a fairly comprehensive trashing of radiative barrier claims versus real-life results. Naturally, one could make the argument that Glacier Bay is somewhat biased since they make $$$ VIP's. However, I have found their claims to make sense.
  • mph
    mph Member Posts: 77
    Insultarp

    I keep seeing claims of how well Insultarp works but have yet to see any actual side-by-side comparisons done with foam vs Insultarp vs no insulation. On that 10k slab, were there uninsulated areas that were compared to the Insultarped areas? I find it hard to believe that this product can perform under a slab as well as the manufacturer claims. Even they have yet to provide any test data.

    I'm looking forward to Hot Rod's test results.

    Jeff
  • Lurker_2
    Lurker_2 Member Posts: 123
    Its all relative

    A wall[or floor] with an r value of 1 has ten times the insulation of one with a value of .1, but a wall with an r value of 5 has only 5 times better than one with a value of 1. That first 1 is the most effective and everyone after that is increasingly less effective, percentage wise. That would be why 'any' insulations seems so effective.

    It is the cost for the effectiveness that is important
  • Insultarp

    I recommend Insultarp to my contractors whenever they don't have the room for rigid polystyrene (blueboard/Dowboard).

    I like the foam component.

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  • Floyd_5
    Floyd_5 Member Posts: 418
    Are you including....

    the regular double bubble .....foil-bubble-bubble-poly products????
  • hr
    hr Member Posts: 6,106
    There are other issues

    to address with rigid foam. Termites, carpenter ants and other insects will burrow and honeycomb the stuff.

    Depending on your area of the country, site considerations, drainage, etc, foam sheets may not be your best choice.

    InsulTarp tells me they have tested their product in the same way as the foam board manufactures, and do not have a problem with insect attacks.

    I talked with the DOW folks at a RPA seminar years back. He told me they have actual colonies of various insects that they use for testing the products in. Sounds creepy, wonder who keeps an eye on the cages :)

    I suspect the aluminum barrier may be the reason. I know in Australia they wrap all under ground ICF installations with a metal wrap (stainless mesh I believe) to prevent termite damage.

    Dow and other foam manufactures acknowledge this problem and a searching for a long lasting, enviromentally safe product to treat with. Something to consider.

    hot rod

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  • booksman
    booksman Member Posts: 2
    billowing up

    I'm no expert, but when our basement contractors poured our floor two weeks ago, it had Insultarp under it. These guys didn't want to have any kind of insulation at all--least of all 2" foam board. Insultarp was a compromise. I figured it would be easier to install and wouldn't cause the "floating and cracks" the guys were worried about. I didn't get to see the pour, but in discussions afterward, the guys were very negative. They described the billowing up you mentioned when air inside the tarp was pushed to one end of a piece during the pour. They told me they had to cut a slit at the ends of each piece to let the air out and finish the job. And unfortunately, the floor does have cracks, although how many of those were directly caused by the tarp, I can't say.
  • Lurker_2
    Lurker_2 Member Posts: 123


    cracks in 2 weeks, bad concrete. I can't even imagine how that could be caused by insulation. Find a new concrete guy.
  • hr
    hr Member Posts: 6,106
    Never seen the billowing effect

    How did the air get inside in the first place? The InsulTarp is tightly hemmed on all four sides. I suspect maybe they cut one end and a bunch of wind got into it?

    I use mesh or rebar in all my pours, can't inagine that billowing happening with that weight of re mesh, or bar on top. I'd have to see that to believe it :)

    Underslab insulation is a hard thing to pin down exact numbers on. The conductivity of the soil is a big, hard to know, number. Rock, clay, wet sand are highly conductive and would dictate entire underslab insulation. Gravel, dry sand, base rock are all poor conductors. Insulation might not be needed under the entire slab. climate plays into the equasion.

    You always, always, always want perimeter and edge insulation. Slabs poured inside foundation walls need that thermal break and expansion joint also.I always suggest at least a 4 foot band under the outer edge of the slab also.

    You need to pencil the numbers. If the insulation cost is worth the downward loss energy costs. Keep in mind no thickness of insulation will STOP heat loss, it merely slows the loss. Even in home construction walls are usually R-11-15 (2X4) or R-19 (2X6) I suppose as energy costs continue to go up better wall, ceiling packages will become code. Although the glass area will always be the largest loss, and hardest area to beef up the R value.

    hot rod

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  • Steve Eayrs
    Steve Eayrs Member Posts: 424
    Problems with concrete guys....


    I have never seen a concrete guys who said he liked insulation under the concrete, BUT they do not have right to double your fuel bill.

    Its a fact that in colder areas the heat loss is doubled (when considering 2" foamboard vs. nothing).

    Have been in more than one arguement w/ the concrete guys about this, and when the owners were consulted, we always won.


    Steve
  • bob_25
    bob_25 Member Posts: 97
    Somethin different

    Way back in the early 60's did a job for a retired engineer he had the concrete contractor pour 4" of cement mixed with vermiculite, this stuff seeemed to be about as dense as blue foam. It was easy to tap a nail into it. We laid copper on it on 6" mesh and they poured a regular 4" slab. I have no idea how well it worked. bob
  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    There are only two things concrete is guaranteed to do...

    One is lay there, and the other is to crack.

    After some #4 Fujita tornadoes in Texas literally ripped up slabs, item number one is in question.

    However, item two is still holding firm...

    ME

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  • Weezbo
    Weezbo Member Posts: 6,232
    To me it has Got to help....

    In Alaska ,we have Plenty COLD...some people like 4" insulation under a slab! no it isnt code no not everyones into it...however long ago and far away just convincing anyone that the concrete would be O.K. after convincing them the value of insulation ,was not an easy sell. many people,who for this momment will go unnamed :) had to place tubing strapped to the mesh or rebar or both and either use polyvynilsheating(what we like to call Visquine) under the slab or not.the phrase i kept repeating at that time was' soon the whole world will be made outa styrafoam....'i missed getting in on styrafoam futures development in the 60's ...thats another story...however...time rolled by, then one day the unnamed person ran outa visquine and had some fiberglass reinforced visquine and threw it into the equasion the GC saw it and decieded that indeed that should be the way to rumble...so i convince everyone to use the styrofoam 1"and it looks really good...so i disseminate pictures...not to be out done all kinds of foam shows up from 3m i think for roofing jobs a buddy hears me say that is the way to travel well...he hada dollar and lashed it up and liked his fueloil bills alot and well it caught on round here like plywood:)ive oops..so the unamed guy installing the 2"foam ran outta visquine one day and thought well theres onea those blue tarps its kinda the right size..:) in our trades Accidential Juxsapositional invention is an everyday occurence:) evidently someone in your area saw the insul tarp thought what the heck Thatillwoik i got somma dis blue foam hey it isnt worth the hassel of dragging all around "I'll Throw it in the slab:) thats the ticket! some banker or engineer came along wondered what the guy had done and Insultarp!newest thing since toast:) having said this...insulation is the key.barriers are excellent and as to the argument 'well, it only slows the heat loss down'..(.What the heck doyasuppose we doing this fo?:)) here it is the -norm- to have insulation under, alongside, on the flat around the perimiter......,in walls ,ceilings ,roofs,garage seperation walls ceilings over garages,3 e windows ....the people here thought that indeed the ideas of insulating this way were a waste of time and money even Hearing me babble about it, at one time. There is a reflective stuff called egale foil..?.. i thought we should all get with installing, the nasa teams developed it... ....whatever....the foil is the same thing pop tarts come wrapped in these days and other food stuff. they were silently marketing it, well lets say, a heavy decade ago:))i was doing everything to convince the guy to make and market 100'X40' rolls of the stuff and i'd convince some of my buddies to drop some in thier up scale homes...No Such Luck...well what can i say....?...........in a nonce,any barrier is better than no barrier.the more complex the barrier evenmicrons thick if made of metals signifigantly enhance the escapage of heat , displacement ,and its containment.i never considered its use as a termite barrier That might sell!:) ......insultarps gotta help.how much i dont know...hope some of the words help you...hot rods got some track record of this and has a pretty good take on it.insulate the perimiter over the tarp looks to be the way to roll with it.
  • ScottMP
    ScottMP Member Posts: 5,884
  • eric legacy
    eric legacy Member Posts: 16
    I love my Insultarp

    I used it and it works great. I have a 6" 4000psi mix with steel mesh and rebar at the door entries. It responds like a gypcrete floor. I can do set back when Im not using the space (work barn) 3to 5 degrees and bring it back up to occupied. temp in about 2 hrs. I used solid pink 1.5" around the perimeter for a neat clean edge. Only had 1 crack it went from 1 side to the other. It basically made its own expansion joint when I put the heat to it. The foil element of Insultarp is what gives it the preformance. It reflects the radiant energy back. Foam does not! Whether or not it holds up in the long run is an unanswered question.
  • eric legacy
    eric legacy Member Posts: 16
    I love my Insultarp

    I used it and it works great. I have a 6" 4000psi mix with steel mesh and rebar at the door entries. It responds like a gypcrete floor. I can do set back when Im not using the space (work barn) 3to 5 degrees and bring it back up to occupied. temp in about 2 hrs. I used solid pink 1.5" around the perimeter for a neat clean edge. Only had 1 crack it went from 1 side to the other. It basically made its own expansion joint when I put the heat to it. The foil element of Insultarp is what gives it the preformance. It reflects the radiant energy back. Foam does not! Whether or not it holds up in the long run is an unanswered question.
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