Howdy all.

I came across some sub-siding today that I’m not familiar with. See the photo…

Here is the situation… I saw some large gaps in the siding seams, so I took a look to see if I could see house wrap of some type and there wasn’t any. The next thing I find is this board in the garage and the stamped print stating; “WATER REPELLENT” - that was refreshing, but I just want to be sure that this stuff is installed right.

That dark coating appears water repellent to me, but what I saw in the gap looked like a plain fiber board type product…is this stuff installed backwards or is it water repellent on both sides?

Thanks in advance.



Thanks for the quick reply Stephen. Based on what I’m reading it appears that it is still meant to be used with a house wrap, but it doesn’t come right out and say it. Any thoughts?

Well Kaiser was sold in 1978 and then again in 1996 so this has been around for a while. I don’t know if the purchasing companies kept the “Kaiser” name or not. This particular product may not be the same as the modern products at the links provided. What year was the home built? Based on what a “house wrap” is designed to do, this product may very well meet those same type of standards. Give me some 30# felt anytime… :wink:

Built in 1970. One of the documents says; “…can be used as a substrate for various air and water resistive barriers including building wraps…” In doesn’t specifically say that the material can be used in lieu of house wraps. Hmmm…

Depending on what doc you read my general interpretation is that this stuff isn’t meant to be installed as a stand-alone option to house wrap or felt and unless I could verify that the horizontal joints are sealed they’d be a problem. No matter how I slice it I think a little bit of investigative work should be done to better understand what is really there.

Update: I missed a statement - it does in fact say that it should be covered with house wrap within 30 days of installation.

I have never seen this style of board. Was there evidence of water intrusion? If the home is 46 years old but you see no issues it has obviously been doing it’s job up to this point. I would make sure to note the gaps in the siding and then let the buyer decide what they want to do.

So you found actual documents on this BRAND SPECIFIC product from 1970? Don’t use modern day instructions for a product that is 45+ years old. Perhaps a call to Georgia Pacific, the last purchaser of the Kaiser Gypsum company, would have some documentation on this specific product.

Greg: There was one area where moisture intrusion had potentially occureed, but I was unable to verify it. The wall appeared to be swollen around a window.

Stephen: I didn’t find a brand name on the board, so no I didn’t find brand specific documentation. I’m not sure that this board is original even or if it was installed later. I clarified that I referenced documents that I could not verify accurately represented the materials and simply stated that I had exhausted my resources and recommend that they contact a contractor that knows more about siding and sub-siding. …that’s all I could really do.