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Knauf EcoSeal and Owens Corning EnergyComplete

A few posts have referenced Knauf EcoSeal and Owens Corning’s EnergyComplete spray-on products for air sealing. They sound like a cheaper, better alternative to flash-and-batt/fill with closed cell polyurethane, but I haven‘t found a lot of reviews. Does anyone have experience with these products? Advantages/disadvantages relative to air sealing by, say, taping the seams of the sheathing, or other options? Anyone have experience with both?

Asked by Ian Brown
Posted Wed, 08/31/2011 - 23:38


22 Answers

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We have used EcoSeal on a few projects so far and it seems to be a good product. Not a lot of data to this point. I have been trying to get blower door test numbers for comparison, but have not tracked anything down as of yet.

I used it on my own house (1900sq ft.) Taped advantech sheathing, ecoseal and damp spray cellulose. Leakage was 950CFM @ 50 Pascals

I definitely think it is a viable alternative to flash and batt or straight foam. The tricky part of the installation is on headers and b/w jack studs. The sealant gets scrapped to a thin layer and it can end up not fully filling the crack leaving gaps.

Answered by Jill Neubauer Architects
Posted Thu, 09/01/2011 - 11:18

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I'm interested in EcoSeal as well - is this something that you can do yourself if you already have an airless sprayer? (can you just buy the product and spray/install yourself?)

It seems to me that this would be much easier and quicker than caulking the stud bay by hand?

Answered by Richard Spackmann
Posted Thu, 09/01/2011 - 15:53

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Chris, thanks for sharing your experience. So, you still taped the sheathing on the outside, and then used the EcoSeal on the inside? So you wouldn't use it as an alternative to tape (or would you, after this experience)? Do you think that the EcoSeal reduced infiltration more than the tape alone would? I guess my question boils down to whether doing both is worth it, and if you just do one, which one to choose?

Good to hear that you were able to use it with cellulose, you weren't stuck with using Knauf fiberglass (not that I have a problem with Knauf fiberglass)?

Answered by Ian Brown
Posted Thu, 09/01/2011 - 23:13

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I would always tape the sheathing. It is easy and cheap to do no matter what the interior system is. We also almost always go with felt over the advantech sheathing because we primarily use natural white cedar shingles for the sidewall and I'm not sure anyone knows how the advantech reacts to cedar long term.

I don't think there is any doubt that the ecoseal improved the airsealing over tape alone (of course I have no real data to support it). Even the best tape job will have some air bubbles and areas that might not get fully adhered. Plus, how long is the tape going to hold? For us it was cost effective and a lot easier then spending a weekend caulking everything myself.

My house was a hers56. We recently just finished a larger home that was almost entirely spray foamed (closed cell) that ended up at hers55. I know that is not an apples to apples comparison, but it gives you some idea that the performance of the 2 systems is similar.

Answered by Jill Neubauer Architects
Posted Fri, 09/02/2011 - 09:27

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Hi Ian,
Its important to note that neither of the products you mentioned are akin to flash and batt or flash and fill methods. Flash and batt or flash and fill assemblies, if done correctly, will prevent warm interior air from reaching it's dewpoint at your sheathing. The OC and Knauf products are for air sealing only, and won't offer the needed R-value to keep the interior side of the sheathing above the dewpoint.

Answered by Justin Fink
Posted Fri, 09/02/2011 - 10:54

Helpful? 1

Re: Knauf Insulation's EcoSEal Air Sealant
Ian, thanks for your question regarding our new air sealant product. Chris, we also appraciate your response, but can add a little color to it. In the interest of full disclosure, I am an employee of Knauf Insulation.

First of all the product s designed to be applied with a high pressure airless sprayer set at betwen 1800 and 2100 psi. This amount of pressure delivers the sealant deep into the crack or crevice sealing the air pathway. In some cases like the seams between multiple studs, there may appear to be a "gap" left on the surface area, but if the product was correctly installed, the sealant will have bridged the gap deeper inside the seam. In cases where too much product has been installed on the durface of multiple studs, or anywhere else that might interfere with proper drywall installation, yes, it can be smoothed over using a drywall knife, rubber squeegee or even brushed down with a cheap paintbrush. Excess material can be put back in the bucket, or used to touch up or hand seal other areas. An experienced applicator typically has very little excess material to smooth over. The high pressure application is the most significant differentiator against hand applied caulk. While those applying caulk are at least making an attempt to reduce air leakage, the caulk itself is merely applied to the surface and does not penetrate the joint. Additionally, inexpensive latex caulks are not likely to provide an adequate expectation of viability.

As to the performance of the product, we now have accumulated data substantiating significant performance. EcoSeal is being used throughout the country on a variety of home types from starter homes to top of the line custom homes. Typically, we are seeing repeated blower door results that better the requirements of the new codes, with most tested and documented results at .2 ACHn or better. Interestingly, some of our better results have also been turned in by those who have self applied the product as opposed to having an insulation contractor apply it. Our best number to date is .089 ACHn on a house constructed in Utah. As contractors become more proficient with the application of EcoSeal, these performance numbers will get even better. Additionally on this blog site, there have been very positive references made to significant performance on the retrofit side as well when using EcoSeal to seal the interface between attic space and livng area.

Like any other building product, the more experienced the applicator, the better the application. Knauf Insulation continues to actively train insulation and air infiltration contractors throughout the country. The performance of the product has been followed quite closely by some of the editors for contstruction related magazines and in the near future will appear several features highlighting builders, EcoSeal and its performance. In addition, EcoSeal has been selected as the air sealant of choice (along with JetStream loosefill insulation) for the passivehous(ACHn @ .06) project in Greensburg, Ks. as part of the green initiative in rebuilding that community.

Chris Brown
Business Development Manager
Knauf Insulation

Answered by Chris Brown
Posted Fri, 09/02/2011 - 11:03

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why don't you report ACH50?
I think the best you can do is "Estimate" ACHn
So it is not really fair to say "Documented"
It depends on the home, the climate and the exposure

With a very ballpark estimate of 20:1 then 0.2ACHn MIGHT be very roughly 4 ACH50
which does not really sound very impressive

Answered by John Brooks
Posted Fri, 09/02/2011 - 14:16
Edited Fri, 09/02/2011 - 14:28.

Helpful? 0

In answer to your question, we do have the information in ACH50 and yes, that is the manner in which most of the information is recorded. As you well know, there is debate on the best way to report air leakage...with some saying that interior volume is not the critical issue, but rather interior surface area. So, it can indeed be expressed in several different ways. Our data is based on blower door testing, so the results have typically been expressed in ACH50. Granted, ACHn takes into consideration the n factor, which is determined by locations, numbers of stories etc. etc, but for a particular house, in a particular location it is relative.

With that being said, ACH50 ratings are in fact documented with the houses we have tested. Is EcoSeal the only solution to generate an impressive ACH50 number? Of course not. However, considering that many of the houses in which we have installed the product are constructed in typical fashion, meaning that only minimal (if any) attention has been paid to framing, backing of kneewalls, blocking of floor trusses into unconditioned spaces etc etc, we are making a difference.

We have never lost sight of the fact that EcoSeal is a tool to be used to help in the battle against uncontrolled air leakage. We realize that it is only part of a systematic approach to the problem of envelope integrity. However, it is interesting to note that most builders with which we are working are starting to pay closer attention to the total construction of the envelope. As a result, ACH50 numbers improve as attention to detail pre-installing drywall or OSB on the garage common wall; backing kneewalls with a rigid material; blocking open floor joists or trusses, reduction in mult studs, value engineered framing etc.

So where are we? ACH50 in the 3-3.5 range has been most common in these typically constructed homes. Impressive? Maybe not considering what we know should be the target. However, as we progress, seal more homes and draw more attention to air leakage, the numbers improve. Applications completed in the last few months have been documented below 2.7 ACH50, with the best so far being 1.64. So, together we are on the right path.

If nothing else, we continue to draw attention to the need for proper air sealing and the construction dynamics that have to occur to optimize air leakage reductions. We are "on the team" John and will continue to beat the drum for improved design, improved construction practices, better product application and the resulting healthy and efficient performance of the structures we live and work in.

Answered by Chris Brown
Posted Fri, 09/02/2011 - 15:28

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Chris, thanks for all your information regardng EcoSeal - I'm definitely interested in it. Can you buy the EcoSeal itself (5 gallons) and install DIY?

Answered by Richard Spackmann
Posted Fri, 09/02/2011 - 19:08

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Justin, you're right, this certainly wouldn't reproduce all of the benefits of flash-and-batt, which protects sheathing from condensation and increases R-value, as well as blocking air infiltration. In my case, I'm planning to use exterior foam to address those other concerns, and am really interested only in the air sealing.

Answered by Ian Brown
Posted Sat, 09/03/2011 - 00:09

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CFM@50, ACH50, ACHn. I prefer ACH50, just because it yields nice easy numbers. 3-3.5 ACH50 is a significant improvement for houses that are otherwise "typically built," although I would hope that my house would be significantly lower than that. Sounds like it's helpful, but not a silver bullet.

Darn, I was hoping for a silver bullet.

Another question, is it vapor permeable? Should I care?

Answered by Ian Brown
Posted Sat, 09/03/2011 - 00:22

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Chris Brown, thank you very much for posting here at GBA. Sounds like I can buy your product, which I will look into. Interesting to hear that spraying cracks between framing members is effective.

Answered by aj builder, Upstate NY Zone 6a
Posted Sat, 09/03/2011 - 09:28

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Double post

Answered by aj builder, Upstate NY Zone 6a
Posted Sat, 09/03/2011 - 11:03
Edited Sat, 09/03/2011 - 11:04.

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I see many comments about Knauf Eco Seal but none about Owens Corning Energy Complete. I have a client (who has recently read the EPA reports..) considering this as possibly safer alternative to SPF foam.. Any comments about Energy Complete, especially with use of their fiberglass batts?

Answered by Ann Lathrop
Posted Wed, 09/07/2011 - 11:51

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Ann, it is the same idea. Only available from insulation installers. Less air going through fiberglass makes fiberglass perform closer to its specs which is a good thing.

Answered by aj builder, Upstate NY Zone 6a
Posted Wed, 09/07/2011 - 12:40

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Ann, I believe there is a key difference between the two products - I've been researching both through their available online literature. OC Energy Complete is a spray foam, which is a key distinction to the water-based Knauf product (which as far as I can tell is similar to a latex paint?). Considering all the reports of issues with spray foam, you may want to consider these reports when opting to use the OC product over EcoSeal.

Answered by Richard Spackmann
Posted Wed, 09/07/2011 - 12:49

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Richard, Energy Complete is a spray foam but....

"EnergyComplete™ System installers do not need to wear full body protection nor do they require an external air supply mask, and other trades can safely work in the home during application."

IMO not anything like spraying an existing home with closed cell... which is to me the riskiest use of spray foam.

Answered by aj builder, Upstate NY Zone 6a
Posted Wed, 09/07/2011 - 16:09

Helpful? 0

Fair enough - I just wanted to point out that the two are quite different, and that should be taken into consideration in selecting the products. I'm not "anti-spf" or anything like that either, I just felt it was a point worth mentioning. I'm in upstate NY as well, and I see that you are looking into ecoseal - are you able to just buy the product without buying their whole "system"?

Answered by Richard Spackmann
Posted Wed, 09/07/2011 - 17:55

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AJ and Richard,
Yes, EcoSeal can be installed DIY. However, one must have an airless sprayer capable of spraying a heavy material. EcoSeal has a consistency out of the bucket somewhere between peanut butter and a heavy milkshake. Although it is a latex based material, it is much thicker than latex paint and will not through a lightweight paint sprayer. The sprayer needs to be a piston type as compared to lightweight diaphragm machines that will not be strong enough. PSI capability must be a minimum of approximately 1750. Recommended spray tip orifice opening is either .013 or .015 with a fan spray size of 4 or 5. As the product is installed with the tip guard directly against the framing structure, fan spray size is not a real issue. For complete information, see the Knauf Insulation website and click on the EcoSeal logo.
As I am not sure just where in upstae NY you are located, here are a few options for purchase, and yes, it is sold in 5 gal buckets.
Henrietta Building Products...Rochester area
Gypsum Wholesalers...Syracuse area
Northeast Wholesale...statewide distribution

Ian, yes it is vapor permeable.

Answered by Chris Brown
Posted Fri, 09/09/2011 - 09:13

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I looked around at your website...concerning EcoSeal
I am trying to navigate to the "Application Guideline Manual "
can you paste a direct link or describe how to get to the detailed instructions for application?

And what about EnergyComplete does anyone have a shortcut to their application manual?

Answered by John Brooks
Posted Fri, 09/09/2011 - 10:22
Edited Fri, 09/09/2011 - 10:25.

Answered by Chris Brown
Posted Fri, 09/09/2011 - 12:00

Helpful? 0

thanks for the link.
What I am finding is a 7 page document.
Is that it?
Do you have a link to a more detailed set of instructions for your "contractors"?

Answered by John Brooks
Posted Sat, 09/10/2011 - 08:37

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