Alaska Home Inspectors

Kevin Jones · Home Inspector

Has anyone else come across a product from Rodda Paint that is basically a latex coating that acts as a vapor barrier in place of the traditional plastic vapor barrier seen in residential construction? I inspected a home and when in the attic found no vapor barrier below the insulation. I was told that the rodda product was used as the vapor barrier. (Applied to the sheet rock). Attached are the product data sheet and MSDS.

If you have seen this product in use do you have any comments or concerns with the products ability to perform. The home I am investigating has some moisture issues in the ceiling.

**Chris Roust** · Site Admin

Although I haven't had direct personal experience with vapor retarder paint, I believe that it is quite effective and as a home inspector I have recommended it in some cases where no ceiling vapor retarder had been installed in existing houses.

About adding pdf files, I was not aware that the pdf file format was turned off by default in the forum. It is now turned on and should work. I am testing it in this reply by attaching the Weil McClain Recall pdf.

Patrick Hartshorn · Home Inspector

If I understand correctly, the drywall is painted on the interior (living quarters) side with this product? I am currious if this would effectively put your vapor barrier on the wrong side of the drywall?? I know there is a lot of contraversy out there about the whole vapor barrier issues (double barrriers, proper placement, sealing outsides & holes, Etc.) but I was taught to never barrier drywall on an interior side! Effectively the moisture potential from the attic would cause microbial growth to come thru the drywall and deter the sealents performance as it eats thru it. There are very few paints on the market today that are considered "encapsulation" products to stop mold growth, they are a last ditch effort when all else has failed and they cost massive bucks.

Any other ideas on this???

Thanks

Pat H.

Kevin Jones · Home Inspector

Okay the attachments are now on the original post. The material was applied on the attic side of the sheet rock prior to installation.

Peter Reece · Home Inspector

If I understand correctly this product has not been approved by IRC 2000, 03, 06 codes or the IEBC codes, and the Data Product Sheet States it is for Interior use, Kevin you have a problem.

Regards
Peter

**Chris Roust** · Site Admin

The IRC calls for a vapor retarder material with a perm rating of 1.0 which vapor retarder paint can easily meet. As Juneau Building Official, I allowed vapor retarder paint meeting that rating to be used on the house side of the ceiling in lieu of poly and I know many municipalities do also. We never heard of a problem using it. This link is to a City of Burien, WA document with a table allowing it.

http://www.ci.burien.wa.us/commdvlpmnt/forms/2006%20WSEC%20VIAQ%20SFR%20Prescriptive%20Form.pdf

Here is another site that I found discussing it.

http://www.daviddarling.info/encyclopedia/V/AE_vapor_retarder.html

On the issue of it deteriorating sheetrock, that should only happen if the attic air were wetter than the house air which is very unlikely in Alaska unless there were a roof leak or lack of attic ventilation causing condensation on the roof sheathing/structure.

I had not heard of a coating to be placed on the attic side of the sheetrock but cannot see how it would be a problem.

That's my take on it at least...

Jim Foss · Home Inspector

Yes, we viewed use of this or a similar product in use in the Hulquist modual home manufacturing plant when our chapter sponsored a plant tour. The homes they build are built from the inside out, so it is difficult to install a vapor barrier. I have recommended this product on 1960 homes that were built without a moisture barrier.
Jim Foss

Patrick Hartshorn · Home Inspector

I would not know what percentage to break my experience into, most of the homes I see are fine with attic ventilation. I do run into a lot of attics that have moisture issues or past issues that have caused microbial growth. Usually this growth is located on the roof sheeting, not in the lower areas near the barrier. I am usually dilligent in letting the client know about the importance of keeping a ventilated attic year round.

I do however like the idea of having the product available for the older homes as mentioned above. My concern would be that if it were painted on the interior side, I would not want it to be the moisture deterent if my attic ever developed an issue. Of course if you were going to go thru the trouble of removing insulation to apply it on the attic side, a vapor barrier would probably be a much better choice at that time.

Recently I inspected a home that had the attic access removed for a long period of time. The insulation was "v'd" in straight lines below each sheeting seem. These areas of insulation were "opened" or "exposed" all the way to the vapor barrier from dripping water due to the heated attic. The only thing that saved the home was the fact that the vapor barrier was properly installed on the attic side of the drywall and held the water away from the building materials. Even a painted back side of drywall would not have saved that one.

Excellent learning topic, I love this forum!

Pat H.

Peter Reece · Home Inspector

Our guidelines are based on the IRC & IEBC for inspections, we are not a
governing body of inspectors, but independent inspectors.
Chris's comment in regard to accepting Vapor Retardant Paint is for a City Building Official to make that interpretation of Data Available at time of Inspection.
The Data Kevin referenced is for "Interior Use", and as we are Independent Inspectors we cannot make Chris's Call.
It sounds as though Kevin has found a home using this product that has failed, since the product is for
"Interior Use", Liability falls on the Inspector who allowed the use of this product, unless they were a City Building Official.
I have recommended this product for older homes just as Jim has, but with exclusions of liability if it fails.
Another thought, what happens when another Inspector comes along in a couple of years with no knowledge of this product ??
I will not be recommending this product any more since Kevin has found a home failing.

Thanks to all responsible for this forum.

Regards

Peter

**Chris Roust** · Site Admin

Kevin, Did I miss somethng? I didn't notice that you said the product or assembly was failing. And didn't you say the product was applied to the attic (wrong) side of the sheetrock?

Peter, I used to be a building official and in my previous post, I was trying to convey that vapor retarder paint had been interpreted as meeting the IRC standards by myself and other building officials. At ICC training, instructors have stated that it meets those standards. Now, as a home inspector, I often use the IRC as a guide for safe and healthy building practices. I have never been informed that the product has caused problems and still believe it could be a great solution for homes without a ceiling vapor reatarder. So, unless there is a failure in a home where the product was used as directed, I will continue to recommend it.

Carol Perkins · Home Inspector

Chris was asking for some input into the forum so I thought that this is a good place to add.

The paint will work fine on the sheet rock as a vapor retarder. As an existing home inspector I would not be in the position to tell some one they have to remove it and I sure would not want a poly sheet on the cold side of the paint. The biggest problem with the paint is the same as a poor job of air sealing and installing poly --- the holes i.e. in and around the light fixtures and outlets. Sealing the holes in the wall cavities.

As a new home inspector my version of the IRC and IECC just says 'vapor retarder' 1 perm or less (Alaska BEES said .6 or less). Their definition of Vapor Retarder: A vapor resistant material, membrane or covering such as foil, plastic sheeting or insulation facing. "Such As" does not preclude the use of another product if it meets the requirement. Rolling Eyes