Need advice on Reflectix and proper insulation under radiant!

Wayco Wayne_2

the other Wayne has a good point if I understand him correctly. After I install a staple up in a crawlspace and it is insulated with the proper air space and either fiberglass or other insulation, I like to recommend some R-max sheathing board across the bottom of the floor joists to prevent any heat from traveling down the joists and out into the crawlspace. It is the bow on the present. It finishes it nicely. :) WW

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DeirdreLouisville

Help! Proper install of Reflectix and insulation under radiant?

Please give an ignorant homeowner a little advice:

I recently had a radiant floor system installed under the existing hardwood floors in my living, dining room and front hall. Total of about 700 sq. ft. on three loops with 3 thermostats powered by an existing boiler at a cost of $7500. There is only crawl space access.

Yesterday, I went into the crawl space to look at the work and found that about half the area had only Reflectix over the pex lines-- no other insulation at all. Further, there were 1-2 inch gaps where the Reflectix had been cut to accomodate existing cross supports. The living room area and a bit of the dining room had unfaced r19 fiberglass pushed up between the joists, but unsecured. A couple were drooping.

At the close of the job (several weeks ago), my contractor assured me that they had followed the manufacturors instructions to "the letter" and that the area was adequately insulated.

Please tell me, can this be true? Is it truly ok to feel hot air flowing out of the reflectix gaps? Is Reflectix by itself adequate insulation in a crawl space installation?

If not, what would be proper installation?

Thanks for any advice you can give!

DeirdreLouisville

Please?

I am on the forum for homeowners too or have I posted on a forum just for pros? Any advice on my problem would be much appreciated....

Weezbo

that doesnt sound like you got more than you paid for.

do not weary from doing good. why not ask a local insulation contractor to have one chance at putting the finish touches to the crawl space as he may see a few things you have no idea needs insulation.?

DeirdreLouisville

Well, I don't really want to pay someone else until I ask the orginal contractor to bring the work up to a reasonable standard. I have no idea what you mean by "more than I paid for". What I am trying to find out here is what does a standard install look like and does my install meet that standard?

Nron_13

standard for us

Is to add an R-12 to 20 of insulation under the floor after the relfective insulation , did they use heat transfer plates and at what spacing ? how is the floor know is it warm and even ? make sure that the insulation is not pushed up around the pipe you want a 1-2 inch gap between the pipe and the reflective foil and then the insulation in right below that and then poly in the crawl space to keep drafts and moisture out

DeirdreLouisville

The pex is mounted slightly below the floor on the joist (to prevent striping I was told). The joists are 16" with pex run on both sides. The floors feel warmish and even, but we had to have the contractors out 2 weeks ago to push the water temperature up as the rooms would not heat above 62 degrees. He changed the boiler temp from 160 to 170 and the rooms are now fine (outside is also higher so we will not know for sure until another good cold snap comes).

Jim_65

Staple Up

The system your contractor installed is a staple up system or joist heating. As Nron stated the air gap is a necessity to make this staple up application work. Be sure to insulate around the rim joist and seal up any opening.

To bad the contractor didn't install heat transfer plates. This would have allowed for a lower operating water temperature and you could push the insulation tight to the plates. Not to mention a greater more even heat transfer.

IMHO Reflectix won't even come close to cutting it.

Good Luck!

Joel_3

Crawl space?

You will loose alot of heat down into the crawl space without more insulation . We recomend r-30 under a crawl space . Personally we won't do it without plates but some here do . With plates we would be more exspensive than people without so you may have gotten what you payed for ? did you have any bids with plates ?

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DeirdreLouisville

The job was done as part of a larger remodeling project, but I am very surprised to see more than one poster suggest that 11 a square foot for a system that hooks up to an existing boiler is cheap.

I was told by my contractor that having the tubes contacting the floor would be potentially damaging to the floors (I have 100 year old nailed down oak floors).

I do not think that I can change systems totally at this point. What I am gleaning here is that I need to have the contractor go back and seal up every opening in the Reflectix and then insulate well below.

DeirdreLouisville

Thanks everyone, one final question.....

I am scheduling a meeting with my contractor-- we will go into the crawl together and look at the openings in the Reflectix (which already has significant dust on it, the house is 123 years old) and the lack of insulation together.

Is this an adequate solution:
1-Tape all openings in the Reflectix
2-Add faced R25 fiberglass

Or should I ask for all the Reflectix to be removed and replaced with something like Thermospan and then insulate underneath?

Also, I assume that once the install is right, that I will lower the water temperature back down to 160 degrees?

Weezbo

Hello again.

The prices vary all over America, be that as it may,...Here goes. the insulation is something that important and requires more than a guess and by golly attitude to do correctly,for the most part.

first the fresh eyes of a skilled worker in that trade often bring in many small subtle differentiations in the finished product...not saying for a momment that i am clueless or your contractor has never seen foam board ,friction fit, tremco, poly sheeting, spray foam, mixing devises plates rim joyst box beams for example....thing is does he see insulating as his line of work everyday ? many times i run around ahead and behind insulators pointing out "details" they respect me even though i do not have a spray gun in one hand a tremco gun in the other a silicon caulking gun in the other a butcher knife in the other the red poly tape in the other and a neumatic staple gun in the other and blaze away at insulating like Shiva at sealing every and any hole crack and crevise against the cold and air infiltration thing is those days are gone for me. the insulation contractors are into what they do or they are out of business.if i see someone fornicating the guys job up ilet the guy know the minor technicalities ofthat aspect of whatever he is doing just to let them fix it and remember that i explained the right way to roll if i see the contractor saying the same thing to the guy i am then going to mention in general (restate) what we both just finished sayin so it sinks in.

that makes sence to me. i am staying with what i am saying. while i have all kinds of tools and certifications lisencing it is a task that i think needs someone devoted to that line of endeavour maybe i just have too much work to do . for you though the things to "watch for" are things that are obviously not "happening". when you see that then you then have reason for concerne and a second opinion is in order if there isnt a clear reason to your question.

ok so how do the placement of pipe ,temps of water ,types of emmitters ,flow of the fluids,work to the advantage of comfort without due attention to infiltration,building envelope,premiter insulation,pressure limitations on the building envelope and a bizillion other things end up all my responsibility ? Who knows?

Yah i can sheetrock mud and tape,frame strike flat work build forms lay carpet and lino,put the roofing shingles down by the square buh really it isnt encumbent upon me to do all that all the time just because i happen to be there working on the plumbing. i am not sniveling or ragging on you .

my thought is foam the perimiter ,use plates unless the floor is totally out of whack or it is a little floor warming in an area ,seal all penatrations that travel from floor to floor,keep all pipes away from the outside ,seal all framing members with tremco along outside rims, soles top doublin kings and trimmers and sills. insulate between floors,and rooms ,insulate pipes hvac pipes water pipes drainage pipes with open crawl spaces ,use friction fit staple up membrane on the bottom of the floor and poly sheating on the ground if the crawl space is insulated if the crawl space has any daylight ,Fix it. fill the perimiter with friction fit after it is foamed and sealed, ...then when your all out have someone else inspect the work. maybe you aint quite as skippy as you think.

Cousin Louie the Fish monger while a great guy and all and whos opinion you highly regard may not be the guy to get to do that inspection though :)yet if He sees something drastically off the wall with it ...it probably is

i have no idea what the designe temps are for your area nor do i know the floor coverings and heat loss for the rooms, i dont know the integrity of the vapor barrier or if there is a ventilation system in place or the positive or negative pressure stradgey you have employed within the remainder of the building envelope. however i will say this,if you get an insulation contractor over there and someone to do a blower door test you wouldnt be shooting yourself in the foot by doing so. and if you dont like my opinion then by all means get another

my thought is you see something "different" thats enough for me to belive remedial efforts if they were already discussed with the contractor then need to be adressed by another set of eyes with on site verification . i dont know anyother way so say what i mean.

DeirdreLouisville

Thank you for taking so much time to explain things ....

Unfortunately, Louisville, Kentucky is a very conservative market. No one wants to do retrofit radiant--it isn't a matter of some guys bidding too high-- I simply can't get bids. There are no local experts that I know of that I could have in for a consult, which is why I turned to you guys....

My home in an 1882 Italianate brick (covered in stucco in 1910) in an historically protected area. Built as a single family, converted to a duplex in 1910, we are converting it back. The recent radiant job was part of that larger project, handled by an well respected contractor team that does a lot of historic house work. I had 8 contractors out to look and received only 3 bids. One of those bids wouldn't even give an allowance for radiant and strongly recommended just removing the radiators that were in the way and capping those lines.

When I read these forums I am amazed by the thoughtful analysis of systems. We just do not have those kinds of hvac people in our area. I live in a fairly afluent neighborhood (populated mainly by doctors, lawyers and busines execs)-- NO ONE that I know of has ever been offered a "heat loss calculation", geothermal is unheard of. My little radiant project is considered way, way out on the cutting edge.

[Deleted User]

I compared refletix once...

compared it to foam, fiberglass, numerous other configurations of bubble foil bubble and determined that it had the same resistance value as 1/2" sheet rock...

ME

DeirdreLouisville

I read your posts on that, Mark. IIRC, you had jpgs of each and a graph showing resulting temps. Based on your experiments and the already substantial dust on my Reflectix, I have no expectation of getting much insulation value from the reflectix. At this point, I see the Reflectix (if properly sealed) as creating a sealed space of highly heated air that we then insulate underneath.

My contractors are new to radiant. I am pretty sure that they just went with what the rep told them. I hope we will be able to work things out to an installation that is effective.

DeirdreLouisville

Correction on pricing

Looking at my total bills, it looks like the radiant total is $9200, not $7500. At first we were only going to run radiant to the front hall at a cost of $1800, but the added the living/dining rooms at a bid cost of $6600. There were then additional charges for an electronic relay control, a valve on a radiator, etc.

[Deleted User]

You've got it..

Actually, its been a couple of years since I posted the results of the experiments we did at the college that I work at. The recent stuff you saw here was below concrete slabs on a snowmelt system.

The gaps in the barrier affect the performance of your system BIG TIME. I don't understand why simple people can't understand this concept. I guess they think that as long as the tub eis in there, it WILL work, regardless of the laws of thermodynamics...

""Heat rises!" is the biggest myth going in this field today. Any way, the R value isn't squat, nor is the spectral reflective capability/qualities.

You NEED a consistent gap to keep the convective portion in the equation, but you also need R value to lower the back losses of the radiant panel, and you don't get R value from the BFB.

I think Waco Wayne has a better idea for creating the box using some sort of duct board. Maybe he'll chime in. The air gap is more ciritical in the long run than is the reflective capacity. Save the aluminum for beer cans!

ME

Ted_9

radiant

Just wondering, but what other radiant controls are there? Are there controls to mix the water temp down? does it use outdoor reset? Is there any boiler protection?

Its not only an issie of hurting your floors, but the boiler as well.

But If your running such high radiant temps, you wont condense in the boiler.

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DeirdreLouisville

There is no outdoor reset. The boiler is a Dunkirk Plymouth Xtreme PWX8 (4.5 years old). There is no mix, it runs the water at the temp it comes out of the radiator. There is a thermometer that measures the temp as it enters the radiant lines and another that measures the temp as it returns. The difference ranges from a low of 6 to a high of 15 degrees at the times I have checked it.

The thermostat in each rooms call for heat when needed, which turns the radiant floor pump on (it only runs when calling for heat). I am surprised at how noisy the pump is, I had expected radiant floor to be a silent operation.

DeirdreLouisville

It was your college experiment that I pulled up with a search on Reflectix-- apparantly those old post stay around for awhile.

Is it essential that the gap be uniform? For example, if the gap is 3 inches at the sides where the reflectix is stapled to the joist, but curves up to 2 inches in the middle, is that a problem (assuming the reflectix is not touching the pex)?

Unknown

it's pretty hard to get a straight 2" gap unless you use rigid foam, and that's pretty tricky.

I think you'll be fine with your intended fix... tape it up and go with more R under the reflectix. Tell the contractor he's wasting his time with reflective insulation in these cases and focus on R and send him here if he wants to find out why

Also, make sure the ENDS of the joists are well packed with insulation and sealed. They are significant areas of heat loss.

Wayco Wayne_2

Chiming in

Wayco Wayne here. I have installed staple up very sucessfully, but ya gotta be careful to do it right. The biggest thing out of my control is the insulation. The insulation companys don't hire rocket scientists to install insulation. (It just doesnt pay). It's hard to find insulators who give a hoot about your project and doing it right. I stole this idea from a nice fellow I sat next to on a plane coming home from Wirsbo mini camp. I use thermopan duct board to make my air gap by boxing in the tubing. Then the insulators can push up against it and not have to worry about the air gap. The reflectix bubble foil could do the same thing but is harder to work with and get a good seal. I'll try to post the pictues I took of a job I did with the thermopan. I have also used R-max insulated sheathing but it is harder to work with. WW

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DeirdreLouisville

Have you used the spray in foams to insulate under radiant?

And, was it more effective that fiberglass batts? Would it also act as a barrier?

Happy New Year to all.

Wayne_16

My opinion is to use foam insulation over fiberglass for most installations in todays economy. Closed cell foam will also seal to the rim joist, wall studs and floor trusses without adding additional vapor barriers. Open cell foam insulates well, is easy to trim if needed, but does require a vapor barrier if required.

p.s. i am not a foam insulation contractor

good luck, Wayne

DeirdreLouisville

I referred my contractor here via email and have received a reply apologizing for the poor installation and stating that they will remove all the existing fiberglass, seal all the Reflectix and reinsulate with kraft faced fiberglass. Although, in retrospect, I think this wasn't the ideal install, it does seem like a fair solution.

I may go back and add rigid foam board after. Thanks to what I have learned here, I will definately add 6 mil plastic to the crawl. Am also exploring the idea of an outside reset for my Dunkirk Xtreme.....

Thanks to all of you for the advice, you guys should consider an "on line" consulting firm for those of us out in the hinterlands (the find a proffessional search came up empty for my entire area).

Kevin O. Pulver

Deirdre another voice,

I too have installed tubing with and without the heat emission plates. Plates are "better" from the standpoint of being able to use lower water temps. They do add to the initial cost, but they are MUCH MORE FORGIVING from the standpoint of the amount of heat they will transfer to the floor. I've heard of people having a system that works marginally, and then they add heavy carpet and pad (where before it might have been linoleum) and all of a sudden it doesn't work anymore. The carpet and pad added enough insulation to ruin the performance. I've also decided the reflective insulation loses it's benefit very quickly. My own home had a new subfloor, and within 3 years there was quite a layer of dust on the foil facing. I would think if they taped the seams good, put the fiberglass back in, you would be in good shape. OR, maybe a better solution would be just make sure the fiberglass is in good, and then cover it with some Tyvek housewrap or comparable infiltration barrier stapled over the insulation. I think that would help keep any drafts out and keep the fiberglass in place over the long haul. I can't speak to price, but I can say that crawl space installations eat up a LOT of time and sometimes you wish you'd never started them. Regardless, you will never regret having installed radiant! Enjoy and Happy New Year! Kevin in Nebraska

Rodney Summers

ripped off

Hello:
Why don't you tell her. She was ripped off to the tune of $6000 - $7000.

Find a pro to act as an expert witness and a consumer protection lawyer...if possible.

zurnie

r- values

You should have 5 times the r-value under your floors as you have on top. Remember to include the plywood and floor
coverings together. As far as tempertures on staple up
anything above above 140-145 degrees will cause glue in
plywood to possibly start seperation.

DeirdreLouisville

Hmmm....There will be no floor coverings (we just had the floors refinished and the rooms are decorated kind of spare and sleek).

The R=value I have underneath is a total of 20 (Reflectix plus r19 fiberglass). I do not have plywood subfloors, the house was built with rough plank subfloors (circa 1882)and the pex doesn't ever touch the subfloor, but it suspended from the joists by plastic rings that mount on the joists.

I would like to add foam board insulation over the joists on my own--can I place the board directly over the kraft faced fiberglass?

Ron Schroeder

One rule of thumb that I seem to remember for under floor radient was the R value below the tubing should be at least 10 times the R value of the floor itself if the space below was unheated and at least 5 times the R value of the floor if the space below was heated.