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Originally Posted by energy_rater_La

best hush up now.. we won't let y'all use our oil & ng.

We don't need it here in Texas.

Originally Posted by carmon

I hear ya not code hear on residential....commercial sometimes depends on the engineer..... i don't disagree with you just not common practice here...

It is required in states enforcing the energy code. Of course if the duct work is inside the building envelop and residential not commercial then it isn't required.

Mastic is the best way to go but give it time to dry before running the system. I presume Winnipeg doesn't use the IECC since you don't.

best hush up now.. we won't let y'all use our oil & ng.

Originally Posted by Datsik

You've said too much. Guys we need to kill him before this gets out

He lives in Lousyana, isn't that punishment enough?

Originally Posted by energy_rater_La

I never use bubble wrap. code allows it in Ma?
not here. and our codes allow R-6.
you might find this article of interest.
http://www.energyvanguard.com/blog-b...diant-Barriers

I only use R-8 ductwrap for hard pipe, and
have to special order it, as supply houses stock
R-6. putting R-6 in a hot vented attic makes no sense
at all. but code allows it. crazy!

You've said too much. Guys we need to kill him before this gets out

Originally Posted by energy_rater_La

seriously...I've used 1403, 1402 seals better IMO.
1403 cuts my fingers, 1402 pulls my fingerprints off!

Once squeegeed down, neither one is coming off again, basically ever!
In a 120º+ attic, you have to be careful where/how you set down a roll of 1402, or it becomes a permanent fixture.
If it hasn't been pressed down yet, 1403 can usually be successfully repositioned, and the roll doesn't stick to the equipment/duct.
The backing tape is also easier to peal off 1402.

installing foil bubble foil & maintaining a 3/4" air space is difficult.
I never believed it (fbf) worked better than a single sided radiant barrier,
in a radiant barrier application in an attic @ the roofline.
and for duct wrap..it is R-2 R-3 AT best, with the 3/4" air space.
I've never seen anyone achieve 3/4" air space.

I've never used it, and never will willingly.
The times where I've seen it used, the installers failed miserably at installing it with the correct air gap, as instructed by the manufacturer.
Just looking at the instructions for the stuff, how the spacers are to be cut and installed before wrapping, I can't imagine it is an easy task for even the most diligent installer to maintain the required air gap.

Originally Posted by mark beiser

Stop buying the cheap stuff, get Hardcast 1403, with the black butyl rubber!

It is easier to work with than 1402, especially in hot environments. The reduced hassle, is worth the price.

hey now!don't be dissing my 1402. it costs me $38+ tax at the other supply house.
which is why I switched supply houses.

seriously...I've used 1403, 1402 seals better IMO.
1403 cuts my fingers, 1402 pulls my fingerprints off!



installing foil bubble foil & maintaining a 3/4" air space is difficult.
I never believed it (fbf) worked better than a single sided radiant barrier,
in a radiant barrier application in an attic @ the roofline.
and for duct wrap..it is R-2 R-3 AT best, with the 3/4" air space.
I've never seen anyone achieve 3/4" air space.

but thats just in my area. it may be the stuff elsewhere??

Originally Posted by Cooked

I read the article. There are things about his description of radiant barriers that defy physics. And maybe, due to his choice of words, it's semantics.

What are your specific issues with what he said?

I ask, because everything he said about radiant barriers, and about how the bubble wrap stuff would have to be installed to achieve the manufacturers claimed R value, is 100% correct.

Around here we are still getting used to increased RNC energy codes that include duct sealing. You're only allowed so much duct leakage and it includes what is lost at the boot going into the conditioned space.
The three most prevalent methods I've heard around hear are Mastic, the Hardcast tape w/ blue writing and black rubber backing, and siliconing every joint. Everyone has their own preference, but it seems the tape is the most popular in my county.

Originally Posted by energy_rater_La

I pay less than $25 a roll for hardcast brand 1402 mastic tape.
and that includes tax.

Stop buying the cheap stuff, get Hardcast 1403, with the black butyl rubber!

It is easier to work with than 1402, especially in hot environments. The reduced hassle, is worth the price.

I read the article. There are things about his description of radiant barriers that defy physics. And maybe, due to his choice of words, it's semantics.

If a fluid or solid of any sort exists in any state it will seek equilibrium, either positive or negative, Doesn't matter if the energy mechanism is conductance, radiance, convection or any other thing in the Milky Way. The mathematics are pretty straightforward and do not lie. The conservation of energy and mass are irrefutable.

I never use bubble wrap. code allows it in Ma?
not here. and our codes allow R-6.
you might find this article of interest.
http://www.energyvanguard.com/blog-b...diant-Barriers

I only use R-8 ductwrap for hard pipe, and
have to special order it, as supply houses stock
R-6. putting R-6 in a hot vented attic makes no sense
at all. but code allows it. crazy!

Originally Posted by energy_rater_La

I pay less than $25 a roll for hardcast brand 1402 mastic tape.
and that includes tax.
materials are charged to homeowner, so what is the worry that
it is a higher cost than paint on mastic. the money saved in time
not used waiting for mastic to dry makes up the difference several times over.

just my pov.

I dont even wait for it to try just wrap it right after with bubble wrap, can be messy sometimes. And i only ask not because of pride but because its also code in relation to duct leak testing

I pay less than $25 a roll for hardcast brand 1402 mastic tape.
and that includes tax.
materials are charged to homeowner, so what is the worry that
it is a higher cost than paint on mastic. the money saved in time
not used waiting for mastic to dry makes up the difference several times over.

just my pov.

Gotcha. And I was just messing with you too.

It is code here and really good practice also. If the duct is in the conditioned space, not a big deal, agreed. If its in the attic or crawl space, it should be sealed. And its almost all in "non-conditioned" space here.

I hear ya not code hear on residential....commercial sometimes depends on the engineer..... i don't disagree with you just not common practice here...

will do..... and its not just because of pride.....its cause its code....

Originally Posted by bigtime

Umm yes.... it leaks outside..... Thats why we seal the ducts....mastic is better than foil tape...lol

o.k ...seal away....

Umm yes.... it leaks outside..... Thats why we seal the ducts....mastic is better than foil tape...lol

where do you think the leakage goes...... outside.... don't think so...... done hundreds of houses zero problems ....and zero foil tape....lol