Temp Coat

[sweeney153]

For the last time!  Not trying to live your life.  We owe it to our fellow Knuts to make an effort to save each other time and wasted expense.  After you insulate you BUILD THE BUS OVER THE INSULATION.  It is a major commitment point.  "people whose opinions I respected".  Got it?  A consensus of the people that have been there.


Good luck with this,

John

 

John Thats what I want. People have told me that they heard its bad.People have told me they heard from knowledgeable people that its great. But no one has told me of any direct information or even who said it. I searched the archivies on this board and others. Some one must have some direct experiance or reasons for their answers. I know there are a lot of guys here who have a lot of first hand knowledge and I respest those opions but if some body gives me an opion and cant tell me why, I dont take it as face valuie. The last person who got away will telling me "because I told you so" was my mom 40 years ago. I am not trying to battle any one just looking for info and shareing what I have found that may be better then what has been used

[JohnEd]

Sweeny,

I am in deep sympathy with you.  Part of my frustration is that nobody except one chimed in.  I honestly think they are burned out on this subject having been through it so many times.  You are certainly getting conflicting info from authorative sources.  I ain't one of those....I just remember.

You might ask Nick Badame as he is an HVAC certified contractor,  I think he used the stuff you are looking at.

There are certified number crunchers here and Sean is high on that list.

Also try Gumpy Dog.  He ha experience and has been where you are and faced the same decisions.


Please forward to me any correspondance from that company where they claim a R factor of 20.  Or where they claim any R factor, actually.

Hear from you soon I hope,

John

[MCI-RICK]

Sweeney,

I spoke with Temp Coat just a few minute ago.  They're sending me a sample too.  They gave me the same figures for coverage and cost.

I'm not sure how to do a quote but I do agree with Sweeney when he said,

"John That's what I want. People have told me that they heard its bad. People have told me they heard from knowledgeable people that its great. But no one has told me of any direct information or even who said it. I searched the archives on this board and others. Some one must have some direct experience or reasons for their answers. I know there are a lot of guys here who have a lot of first hand knowledge and I respect those options but if some body gives me an opinion and cant tell me why, I don't take it as face value. The last person who got away with telling me "because I told you so" was my mom 40 years ago. I am not trying to battle any one just looking for info and sharing what I have found that may be better then what has been used".


I'm not trying to create bad sentiment or hurt anyone's feelings but I won't automatically rule out the possibility that there may be a better way.

I wish more busnuts would weigh in on this subject!

Rick

[MCI-RICK]

JohnEd,

They told me the R-value drops to about 10 @ 20 mil thickness when used inside the bus.  The rep said Prevost applies it to the outside of the roof and from the inside, they apply it to the walls & floor.  He added that Prevost then goes over that with a 1/2" insulation to raise the r-value and help deaden sound.

Rick 

[HighTechRedneck]

I think it is worth experimenting with as an additional to standard insulation.  (Rick beat me to this post, so what he found out verifies most of what I am saying below.)

Reading their spec sheet, it appears to me that their references are all about radiant heat transfer (i.e. direct sun).  And it seems to me they are recommending it in addition to standard insulation practices which woud be consistent with that.

ACCORDING TO RADIANT HEAT TEST RESULTS IN A ROOF TOP APPLICATION, TEMP-COAT®/Temp Won, WHEN APPLIED TO A THICKNESS OF 15 MILS, PERFORMS AS WELL AS A 4" THICKNESS OF FOAM WITH AN R-20 RATING.

"R" FACTOR EQUIVALENCE:
NOTE. Due to the absence of air flow, an "R" factor cannot be used and all tests are performed comparing the usefulness of this insulation with an "R" Factor Equivalence.

As someone who lives full time in my bus conversion, being in it much of the day in direct sun, I can say that anything that helps with radiant heat is a good idea.  My rigid foam board insulation is incredibly effective in the winter.  When the problem is mainly heat loss by conductance.  And it is very effective if I am parked in the shade even when the outside air temperature goes over 100°.  Again sitting in the shade, my insulation is proving very effective against conductive transfer of the heat from the air.

But when the summer sun hits the bus with all that radiant heat the temp inside goes up fast and it is a tough fight for the air conditioners to beat it.  If this product works and were applied to the inside surfaces before putting in rigid foam board, I can see how that would help some.  If it is applied to the exterior of the roof that would make even more sense as that would limit heating of the roof skin and thus heat transfer as conductive heat.

The issue I've heard with similar products though is they have a granular surface texture that collects dirt and mildew.  As the gloss diminishes, more radiant heat becomes conductive heat as the surface temperature rises.

When you guys test your samples, please report back about the texture of the finished surface.

[sweeney153]

John

99% of the info I have is directly from their web page http://www.tempcoat.com/ They have MDS, Spec, manual etc. Ill be honest a lot of those numbers are over my head. Maybe some of the more knowledgeable guys will take a look and give an opinion when they have the time.  I have read some of Sean's responses and he definitely is thorough.  Sean and Grumpydog and others have a great deal of knowledge and seem to put a lot of thought and work into their answers. Their view on it would be appericated.

[sweeney153]

From the emails I've gotten several bus nuts are getting the information packages and sample.
I guess by next week we will have more direct information. By the way I got my package today.
To bad I won't be able to do my testing for a few days.

[niles500]

One reason why some are skeptical of the claims made by this company is that radiant heat deflection is not measured in "R values" (I saw the reference to the disclaimers - but they continue to tout the R value rating) - another reason is that radiant barriers are most/only effective with ventilated attics - that being said I HAVE USED a product called "tech shield" for roof decking on residential and light commercial structures WITH heavily ventilated attics (continuously perforated soffits, steep roof pitches, high volume ridge vents) and it dramatically reduced the attic ambient temps - I believe, through my experince, that the effectiveness in a bus would be greatly reduced due to the lack of a ventilated crawl space and the amount of conductive heat transfer inherent in a bus - Now one of those Saudi double roof buses would have huge possibilities of success using such a product - FWIW

[JohnEd]

Niles,

I think you are spot on.  And I think you said it more clearly than I.  So for that I hate you.(LOL)

Mike,

I like the idea of "augmenting" the r value of the foam sprayed over the stuff.  What does your intuition tell you would be the result of your having used only this product and not used any sort of foam?  I think I know the answer.  That condition is my motivation trying to get more and better analysis before they lock up the attic and walls for the summer.  In the summer it would reflect the radiant heat from the outside and in the winter the inside layer would reflect the heat back into the bus.  How much benefit and at what cost?  I think that was the rub.

Sweeny,

I don't have any explaination why Sean or GUMPY haven't jumped in.  Try sending each a PM.  I know each is generious to a fault.

Good luck,

John

[MCI-RICK]

Does anyone know what R-value is achieved with the sprayed-in foam or the rigid foam board? and how thick the rigid foam needs to be?  It would be nice to have a benchmark to compare against when considering other products.

Rick

[HighTechRedneck]

John, I think it would pretty much have to be used in conjuction with traditional insulation in a bus environment (which is the way they are recommending it and the way they indicate Prevost uses it).  Used on the roof exterior I can see how it could help a lot when in direct sun, if it can be kept clean as easily as regular paint.  But if one were to use it as the only insulation (that does not seem to be what the manufacturer is suggesting), I don't think it would work well enough.

Rick, the rigid foam board I used had an R value of about 6.5 per inch of thickness.  I don't know the rating on sprayed in foam.  I think it is similar, but has an advantage in that there are no seams.

[Sam 4106]

Hi guys,
You want personal experience? Here's mine. I used that product, or a similar one, on the exterior of the roof of our 4106 because the interior was already finished. It DIDN'T work, that I could tell, from the begining and as it got dirty it still didn't work. I applied it with a roller so perhaps there is more texture than if it would have been sprayed, but in my opinion it was a wasted effort as far as any insulating value.
If you choose to use it I hope you have better luck. Looking back, I wish I had just painted my roof bright white.
Good luck with whatever product you use, Sam 4106

[sweeney153]

Well I spent some time reading the info I received from Temp Coat. They sent test reports from universities, government agencies, testing companies, The Navy and Coast guard. Unfortunately I think I need an engineer to explain it to me. I know some of the engineer type bus nuts have sent for the info so I'll just wait for them to look at it. This weekend ill do my box tests and report back.

Niles

About the R value, that was my mistake they say equivalency R value which is what all the testing papers call it. I didn't know there was a difference and left out the equivalency

Rick

I hope when you get the info you are better at understanding it then me and if it really is R10 when sprayed inside that would be great as far as I'm concerned. When used in conjunction with foam it would give me about R18 per inch.

Sam

Thanks for your personal report. My roof now is bright white and I don't think I would put it on the outside if it's textured. Like you say it would get dirty and not work as well, besides it would look bad. I could see that working in a commercial situation where they run the bus through the washer but my washer is me with a bucket and brush on the roof. I don't want to have to wash it more.

[MCI-RICK]

Sweeney,

I'll let you know when I get it and have read through it.  If it is an R18/inch, with the foam, that would work for me too.

Rick 

[JohnEd]

Rick,

I think you need a vacuum to get up to R18 per inch.  Just a little levity there.

The spray hot foam is the HIGHEST R factor you can get.  Billionare architects spray the walls in their own home with the stuff in order to get their houses certified in the highest category of GREEN.  If there was something better I think those birds would be using it.  It is R7 plus per inch.  The runner up is the foam board with foil backing.  Nobody I have see only puts in one inch.....what I have seen is 2 inches and with furring strips....2 1/2 inch.  So R14 to 17.5 in two inches.

Part of my heart burn is that we are being monitored by a lot of people and some will make decisions based on what we finally come up with and publish here.  We owe it to the next up at the plate.

I think we have come to a conclusion with this:  The stuff does work as a reflector of radiant heat.  It finds use both inside and out.  It is a thin, paint like coating.  Prevost uses it as a underlayment for their hot spray foam wall and ceiling insulation.  The Navy approves it for application to the 2 to three inch "lagging" that covers every exterior wall on the inside surface.  The Navy at one time approved "ASBESTSIS" for lagging, so don't look to them for cert and I worked for the Nav for 20 years.

OK!!!!
John