Radiant Insulation - Did I get screwed?

[mopar440_6]

So, the more I read on here and the less I'm liking what the sub-contractor did.

Building Specs:
50'x60'x14'
Pole frame, glu-lam posts
1x 16'x12' door with power opener
2x 8'x8' manual doors
Radiant heat in floor, 9 loops, 1/2" PEX on 12" centers
5" slab with 4'x4'x10" pads for each of the two post lift posts
Full steel liner
R19 walls
R31 ceiling

The original quote for the radiant install said 2" foam board, well that subcontractor was busy so my GC went with a different guy. He came in, added 2" of extra stone and put down this stuff: http://www.houseneeds.com/heating/r...-under-concrete-insulation-slab-shield-se400t

At this point, the tubes and wire are already down and they're planning to pour tomorrow so the only way to fix it would be to tell them to cancel the pour and pull everything back out and start over (at a significant additional cost).

So, my questions for the experts, is this place going to be impossible to heat? If it were your building would you tell them to stop and pull the entire radiant system out and replace it with 2"XPS?

 

[toyotadriver]

Hate to tell you this but if you use that instead of 2" XPS, your radiant floor heating costs are going to be much higher. That stuff won't do **** to keep the heat from the slab from heading into the ground.

You live in PA so you have plenty of heating days.

If I was doing a radiant slab, I wouldn't have less than 2" XPS under the slab.

Sorry.

 

[ebonyswan]

that stuff is really really cheap compared to XPS - and only r-value of 2.9? I wouldn't feel good about it....

 

[Randy in Maine]

Call the GC and talk to him. Do it before they do the concrete pour.

 

[Slowgsr]

Im with everyone else, especially since yoy have no foundation with a thermal break down to the frost lines, the outer perimeter of the slab is going to take on extra cold. Can you just keep the extra 2" of gravel?

 

[Rookie2]

I see foam board down , Is this correct ?

With that double bubble, you'll heat down 6'. your boiler will never stop.

RECALCULATING RECALCULATING !

 

[CNGsaves]

Hope you got the train stopped OP . . . . Good luck.

Sometimes you have to be a Tasmanian Devil when other people fawk up !!

 

[HoosierBuddy]

I guess the good news is they haven't poured the floor yet.

That would have been a lot harder to fix.

Phil

 

[404]

Do not let this stand. Force the General to do what the contract states.

This corner was cut so the GC could make extra profit. Nail him to a cross and set it on fire.

 

[mopar440_6]

Call the GC and talk to him. Do it before they do the concrete pour.

Hope you got the train stopped OP . . . . Good luck.

Sometimes you have to be a Tasmanian Devil when other people fawk up !!

Called the GC this afternoon, concrete pour is cancelled. Looking at a delay of at least 3 weeks now but I'll take that delay over 30 years of not being able to heat a building that cost me my life savings.

Im with everyone else, especially since yoy have no foundation with a thermal break down to the frost lines, the outer perimeter of the slab is going to take on extra cold. Can you just keep the extra 2" of gravel?

Can't keep the gravel, man doors are already set to height. Would have to cut them out and replace them. Labor to remove gravel and re-level (they never leveled it in the first place) will be cheaper than replacing the doors.

Do not let this stand. Force the General to do what the contract states.

This corner was cut so the GC could make extra profit. Nail him to a cross and set it on fire.

GC was completely bamboozled by the HVAC/plumbing guy. GC is going to work with me but wants me to work it out with the HVAC guy. Just got off the phone with the HVAC guy who tried to tell me that this stuff is better than 2" XPS because it has the aluminum sheet in it. Sorry, I've got a Mechanical Engineering degree, I understand the difference between radiation, convection, and conduction.

I'm heading out to the HVAC shop in a few minutes to talk to him in person but I'm pretty sure I'll end up doing my own insulation and heating system at this point...

 

[Thumper68]

Feel bad for the GC on this one you signed a contract for 2" xps, it is up to the GC who hired the guy who didn't follow the contract so it is up to him to make it right.

I would stick to my guns on this one and take any remaining payments due and put them in a escrow account with my attorney until things are worked out.

 

[404]

Does that sound likely to you? GC Bamboozled with all his years of experience?

I take it the GC hired this HVAC guy? The only reason to hire a GC is so you do not have to deal with subs. Otherwise, the GC has no value.

Who is paying the HVAC guy, you or the GC?

IF the GC is paying the HVAC guy, said HVAC guy does not care what you think.

I do not buy this "oh shucks shuffle" for one moment.

I say these are lies, used to pacify you and wear you down. I expect the GC and the HVAC guy have been doing this for years, and spend weekends together playing hide the salami with an ewe.

Yes, I had a house built and dealt with the GC (who ran away with the money) and the subs that did not get paid.

Best advice is to distrust, and verify, everything you are told and all work that is done.

If you do your own insulation, get money back for what the GC agreed to failed to do in the contract.

 

[finn]

That bubble wrap wouldn't pass inspection here for radiant heat.

I didn't see an "R" value in the advertisement: That's because there is none.

 

[gnpenning]

As others have said GC should be taken care of this. If you have to be doing the GC job make sure you don't pay him for the part you did.

Make sure all exterior concrete has a thermal break between it and the heated slab.

Any time you give a check make sure you get a signed lien release for materials and labor for all subs. No one is watching out for you so make sure you are.

BTW you will love the radiant heat.

 

[DC73]

Just got off the phone with the HVAC guy who tried to tell me that this stuff is better than 2" XPS because it has the aluminum sheet in it.

B.S.! and tell him I said that. You are doing the right thing by pulling the plug.

I don't know if polyiso is acceptable for this type of installation but if it is, it has a higher r-value than XPS and also has a foil side for radiant barrier purposes.

XPS is R5.0 per inch
Polyiso is R6.5 per inch

I'd be surprised if the product you linked has an actual r-value any higher than 1.0.

DC

 

[brewchief]

I'd be surprised if the product you linked has an actual r-value any higher than 1.0.

DC

It appears to carry a 2.9 R value based on the manufacturer specs.

This type of product typically gets it's R value with the use of an airspace, hard to provide for that under concrete.

Concrete guys and some HVAC guys love this type of product because it goes down fast and is easy to work with and they are not paying your heat bills for the next twenty plus years.

 

[dfiler2]

You are doing the right thing, being set back 3 weeks will be a small inconvenience in a few months. I work for a boiler manufacturer and many people are really unhappy with their heat load after using these products especially when they have other buildings to compare.

 

[mopar440_6]

Well, crisis averted, I think. Keep in mind, the GC and the HVAC contractor are Mennonite/Amish guys who are used to building barns. Also, there was no official contract, the GC just gave me an estimate for the building and one from a different HVAC sub for the radiant (that was the original estimate that spec'ed 2" XPS). It's pretty much a time and materials job so I expected to babysit this job a bit.

I went to the HVAC contractor's shop and met with him in person. By the time I got there we had both calmed down enough to have an adult conversation. We talked for a good two hours and called my GC twice. I made some concessions which will result in a bunch of work on my end but if I have to do it myself to make sure it's right, so be it. I came home and pulled the entire underslab this evening; tubes, wire, and "insulation." The HVAC contractor is going to take back the foam/aluminum **** and refund that in full. He gave me three bags of the tubing staples to use. My GC is going to come back tomorrow, pull the form board off the main door, and take out 2" of stone and level it up and cut me a break on the labor. He's going to have enough 2" XPS delivered to do the floor and perimeter. I'm going to spend my weekend drinking beer and putting the insulation and radiant floor system in correctly. I.E. 2" XPS (joints sealed with house wrap tape), tubes stapled to that, wire mesh on 2" rebar chairs. The GC said if I can have it done before Monday, he can pour the slab this time next week.

That bubble wrap wouldn't pass inspection here for radiant heat.

I didn't see an "R" value in the advertisement: That's because there is none.

Well it's not the typical bubble wrap stuff. This has 1/4" closed cell foam on either side of the aluminum sheet. Says it has a crush resistance of 70psi but I can pop the air pockets with my hands. Doesn't matter either way, the second it's in contact with a surface on either side its no longer radiant heat transfer, it is now conduction and guess what, aluminum is a FANTASTIC heat conductor.

The scary part is that the inspector didn't have an issue with it.

It appears to carry a 2.9 R value based on the manufacturer specs.

This type of product typically gets it's R value with the use of an airspace, hard to provide for that under concrete.

Concrete guys and some HVAC guys love this type of product because it goes down fast and is easy to work with and they are not paying your heat bills for the next twenty plus years.

This stuff says its actually designed only for use under concrete. I think the HVAC guys are getting away with it because of the play on words with the word radiant. Radiation and conduction are two completely different animals. No airspace, no radiation.

You are doing the right thing, being set back 3 weeks will be a small inconvenience in a few months. I work for a boiler manufacturer and many people are really unhappy with their heat load after using these products especially when they have other buildings to compare.

And that is exactly why I caught this, a close friend is a lead architect at a BIG firm near DC. He had done a basic heat load calculation based on the original design with XPS. I sent him the information on what they actually put down and he came back with a heat load calculation that was more than double. I called him and he said, "Yea, check the specs, that stuff is only R2.9."

The HVAC contractor's main business is installing outdoor wood boilers so I can see how he's getting away with using this stuff. When you've got a million BTU's on tap, you're not gonna notice that you're burning through a bunch of extra wood.

 

[mopar440_6]

Now, the questions.

The ground underneath the building is compacted slate on top of undisturbed sub-soil. It is WELL compacted because I did it myself. On top of the slate is 2 inches of 1/2" screened gravel.

1, So, do I need to compact the gravel also? I know 2B (1") washed gravel does not compact well but I don't know about 1/2"

2, If I seal the joints of the XPS with housewrap tape, do I need a vapor barrier underneath?

 

[kj_mustang]

My non-engineer, 2 cent internet advice.
If it is crushed gravel, you should compact it. Round pea gravel will not compact and I would not use it.
I would put down a vapor barrier. 10 mil plastic doesn't cost much. Overlap the plastic seams by a foot and you shouldn't have to tape the xps then. This keeps all the moisture away from the xps.

 

[mopar440_6]

Just talked to the builder, they're going to compact it after they take out the additional stone today so that's taken care of.

Anyone else have thoughts on the vapor barrier? I'm planning to tape all seams in the XPS anyway just to keep all the sheets together.

 

[HoosierBuddy]

Glad you were able to resolve this.

I too ran into this with my Amish-built garage addition. I really love the finished product, but a certain amount of trust and oversight was required to make sure things got done properly.

And it the end of the day, "It costs what it costs". All the risk for overruns was pretty much in my court as there was no written contract. Of course, he took the risk that we'd get to the end and I wouldn't pay him.

It's a crazy way to do business, but seems the norm for them.

Phil

 

[4cyclic]

I had the insulation panel seams taped and a 10mil vapor barrier installed on mine. Probably overkill, as water will not go through xps.

 

[Radix2]

Molar - do you have the time to trench in vertical insulation panels around the perimeter to keep the cold out from under the building? That would be another improvement if you are getting serious on making your package as effective as possible.

 

[mopar440_6]

Molar - do you have the time to trench in vertical insulation panels around the perimeter to keep the cold out from under the building? That would be another improvement if you are getting serious on making your package as effective as possible.

No, that be nearly impossible since the building is already up. We would have to dig directly under the existing walls and it would also disturb the footings of the posts.

 

[Radix2]

No, that be nearly impossible since the building is already up. We would have to dig directly under the existing walls and it would also disturb the footings of the posts.

Darn autocorrect! I typed Mopar!

You could also improve the system by adding insulation outside of and around the perimeter as shown on the frost protected shallow foundation plans.

As it sits, the ground will freeze up to and under the slab for a few feet, if you have any soil there subject to frost heaving, it may be an issue with cracks or maintaining a seal under your walls. Your under slab gravel and drainage are your only protection, but that is usually enough. Just something to consider when converting a pole building into a conditioned and tight space.

 

[Lassen Forge]

We had a contractor like that - one time. His subs were awful, he kept substituting cheaper, crappier stuff and lying about it (I know the difference between a sheet metal bathtub and the cast iron one we specced), would whine and snivel how "we were costing him money" when we caught him or one of his subs in their Jackassery... I had to babysit EVERYTHING, because of this slimeball's game.

Adding insult to injury, when he was *finally* done with this fiasco, he had the gaul to send us a bill for an additional 22 large on top of the final amount. We ended up getting the lawyers involved, and he crawled back into the woodwork like the termite he turned out ot be.

What I should have done at the FIRST sign of his games was to fire him. Honestly, having been thru what I did, if someone tried to pull what happened to you on that, he'd be done and gone. Sorry... but yeah, you've defaulted on the contract, and you're done - now go.

And the Gosh Golly Gee Whiz stuff - sorry, you're a contractor, if you don't know what you're doing, you don't belong here. And being "Amish/Mennonite" is no excuse - they have the same rules and regs as anyone else. If that HVAC Contractor is "bamboozled" by his trade, um, then he can go home. And so can the dip that hired him.

The hardest lesson about hiring a contractor - for me - was learning how to be an unforgiving mean-as-hell cast iron *****, and demanding that azzole did it my way, not his slopshod cutcorners lie-and-cheat way. If you lost money - then you didn't estimate the job right, did you? Ain't my fault you don't know how to do your job. And... this is important... You weren't hired as a "Friend" you are my EMPLOYEE, and if you can't do the job then you're fired.

 

[Randy in Maine]

Suggestion:

After the stone is removed and the base is re-compacted, just put down a 6 mil or 10 mil vapor barrier. Then the 2" of foam. If it were me, I would cut some 2" thick foam about 6" tall and put it between the poured floor and the walls to create a thermal break between the heated floor and the unheated wall. Kind of where the light green shows in your photo above.

You may also want to install a few "pull pots" into the concrete floor in front of the doors in case you every want to hook up a winch to pull in a dead car in.

Nice building though. You will get a lot of use out of it.

 

[mopar440_6]

Suggestion:

After the stone is removed and the base is re-compacted, just put down a 6 mil or 10 mil vapor barrier. Then the 2" of foam. If it were me, I would cut some 2" thick foam about 6" tall and put it between the poured floor and the walls to create a thermal break between the heated floor and the unheated wall. Kind of where the light green shows in your photo above.

You may also want to install a few "pull pots" into the concrete floor in front of the doors in case you every want to hook up a winch to pull in a dead car in.

Nice building though. You will get a lot of use out of it.

Based on the input from you and everyone else, I'm going to put down a 6mil vapor barrier under the 2" XPS. I am already planning to cut 9" (band board around the perimeter is a 2x10) strips of XPS and place those tight against the band board and run the floor sheets tight against the perimeter insulation.

Good call on the "pull pots." I'll be looking into those.

 

[Rookie2]

I used power wheelbarrows and had to lay down plywood to protect the pex !

 

[404]

We had a contractor like that - one time. His subs were awful, he kept substituting cheaper, crappier stuff and lying about it (I know the difference between a sheet metal bathtub and the cast iron one we specced), would whine and snivel how "we were costing him money" when we caught him or one of his subs in their Jackassery... I had to babysit EVERYTHING, because of this slimeball's game.

Adding insult to injury, when he was *finally* done with this fiasco, he had the gaul to send us a bill for an additional 22 large on top of the final amount. We ended up getting the lawyers involved, and he crawled back into the woodwork like the termite he turned out ot be.

What I should have done at the FIRST sign of his games was to fire him. Honestly, having been thru what I did, if someone tried to pull what happened to you on that, he'd be done and gone. Sorry... but yeah, you've defaulted on the contract, and you're done - now go.

And the Gosh Golly Gee Whiz stuff - sorry, you're a contractor, if you don't know what you're doing, you don't belong here. And being "Amish/Mennonite" is no excuse - they have the same rules and regs as anyone else. If that HVAC Contractor is "bamboozled" by his trade, um, then he can go home. And so can the dip that hired him.

The hardest lesson about hiring a contractor - for me - was learning how to be an unforgiving mean-as-hell cast iron *****, and demanding that azzole did it my way, not his slopshod cutcorners lie-and-cheat way. If you lost money - then you didn't estimate the job right, did you? Ain't my fault you don't know how to do your job. And... this is important... You weren't hired as a "Friend" you are my EMPLOYEE, and if you can't do the job then you're fired.

Excellent, thank you.
Yours and mine must have interbred at some point.

 

[DC73]

It appears to carry a 2.9 R value based on the manufacturer specs.

This type of product typically gets it's R value with the use of an airspace, hard to provide for that under concrete.

The bubble wrap industry is notorious for overstating r-values. I remember reading one third party report that demonstrated bubble wrap with an air space didn't have much more r-value than just the air space by itself.

DC

 

[BadgerBoilerMN]

Stay focused. If anyone claims that a sub-slab radiant barrier exists anywhere, he is either a liar or a fool. Most of the wood boiler industry is based on trial and error, more of the latter in fact. And then there is the serious DIY element, asking your peers for help...

2" XPS is the standard in most of N.America and rightly so.

Since when are the Amish authorities on radiant heating? Where did they go to school for it? What books have they read.

They work for cash and on the cheap. This should not be a great surprise.

Who designed the system?

 

[mopar440_6]

Stay focused. If anyone claims that a sub-slab radiant barrier exists anywhere, he is either a liar or a fool. Most of the wood boiler industry is based on trial and error, more of the latter in fact. And then there is the serious DIY element, asking your peers for help...

2" XPS is the standard in most of N.America and rightly so.

Since when are the Amish authorities on radiant heating? Where did they go to school for it? What books have they read.

They work for cash and on the cheap. This should not be a great surprise.

Who designed the system?

There was no design of the original system. He just kinda threw the tubes down where they fell.

BUT, since last Wednesday, it has all been removed. GC came out last Thursday and removed 2 inches of stone, leveled and compacted what was remaining and brought me 100 sheets of XPS.

A friend helped me out over the weekend putting down a 6mil vapor barrier and 2" Owens Corning XPS (15psi because that's all that any of the local places had in stock) all seams taped.

Tonight another friend came over and helped me finish running all of the loops. Wire will go on 2" stands tomorrow, concrete is getting poured Wednesday.

I did the (second) design in LoopCAD myself. Had to work with the PEX I already had so the loops are a bit longer than ideal. (313ft to 332ft). It's not perfect but it should work better than the 44% difference in length, hacked together mess they gave me the first time. 5.5% difference between the shortest and longest loop. Designed for 20*F delta T and flow rates all between 0.54 and 0.59 USGPM.

 

[BadgerBoilerMN]

Sounds perfect to me. The only reason for equal loop lengths is eliminating the need for balancing, rarely done in any case.

150 is sufficient for all but the heaviest vehicles or traffic.

 

[mopar440_6]

Sounds perfect to me. The only reason for equal loop lengths is eliminating the need for balancing, rarely done in any case.

150 is sufficient for all but the heaviest vehicles or traffic.

Thanks Badger. Coming from you that gives me a lot more confidence in the system.

 

[BadgerBoilerMN]

I am glad you will have a happy ending and that you shared your problem with others, as there is still much confusion in spite of the 3 decades of experience the industry has had with nearly perfect results.

Well done.

 

[mopar440_6]

Well, after 4 brutal days of busting my **** (and a LOT of help from the DW and a couple close friends), we're ready for the crete. Hoping to be able to snap a few pictures of all of the underslab before the trucks roll in the morning.

 

[BadgerBoilerMN]

We keep the air on at 30# minimum during the pour and always have one of our techs onsite until the end.

 

[rburke65]

You will never regret taking the time and the effort to redo your pex installation like you have done. Wasn't easy but very worth it. Good luck on the concrete pour.