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A Building Enclosure Double Disaster – Control Freaks Missing Again

A House Without A Water Control Layer Will Fail In A Wet Climate.

Building a house is expensive enough already. Why would you want to spend a bunch of money fixing something that could have been done right the first time…or the second time? Well, no one intends to have to spend that money, but the result of not understanding the control of moisture in building enclosures is just that. And a lot of money every year is wasted fixing problems that could easily have been avoided if a good Building Enclosure Control Freak had been involved.

The photo above shows a home in Kentucky (climate zone 4A) that The Building Performance Group in Louisville posted on their Facebook page. This one was taken in January of this year. It’s a 20 year old home and had extensive moisture damage under the vinyl siding, so they pulled everything off and found…

Drainage planes are kinda important

Beneath the vinyl siding, they saw only oriented strand board (OSB). No house wrap. No felt paper. No Zip System sheathing. No drainage plane of any sort. The building enclosure in this home was naked under its cladding, and that wasn’t a good thing. It was missing the water control layer.

In an uninsulated building with a lot of air leaks (or in a building in a dry climate), this might work out OK. But this home is on the wet side of North America, and the walls were well insulated, having been built out of structural insulated panels.

Cladding materials do not keep all water out. Drainage planes, for that matter, don’t keep all water out either, but their job is to reduce it to an amount that the building assemblies can handle. This house had nothing between the vinyl siding and the outer OSB layer of the SIP wall. OSB is made of chips of wood. It can absorb water. It can rot.

(Two great sources of info about drainage planes are: Understanding Drainage Planes by Joe Lstiburek and All About Water-Resistive Barriers by Martin Holladay.)

The wrong fix

This problem lasted 20 years before the owners finally had to do something about it. When the contractor they hired pulled the siding off in January, they found the mess you see above. Their solution was to nail up new OSB over the rotten OSB and then put housewrap and new siding on it.

The photo below shows the house this week, with the new siding coming off after only 4 months.

water damage no drainage plane kentucky second round 440

As it turns out, not only is having a drainage plane important, but so is letting wet stuff dry out before you cover it up. The January contractors installed the new OSB over the rotten and wet old OSB. All that water had to go somewhere, so the new OSB absorbed it, swelled, and bowed the new siding.

How will they fix it now?

According to Eric George, owner of The Building Performance Group, the original OSB is “so deteriorated that you can’t nail or glue anything to it!” He said the windows were not flashed properly either, and the first repair, although they added housewrap, did not correct the flashing problems.

Now they’re faced with going back in and having to do almost everything over again. Because the wall is framed with SIPs, the repair job is a little trickier. They could remove the SIPs completely, of course, and reframe with two-bys. If they try to salvage what they can of the SIPs, they’ll need to address the structural issues since the new OSB won’t be bonded to the foam the way the original was. (It helps that this is a gable end wall.)

However they address it, one other item sticks out like a dead possum in an encapsulated crawl space: There’s no overhang. Extending the rake above that wall would help control water and minimize the chances for future moisture problems.

Building failures are almost always a result of moisture. Mostly it’s liquid water that comes out of the sky. Become enough of a building enclosure control freak to control that, and you’ll be doing a great service to homeowners…and their wallets.

Besides, it’s always good to recall what W.C. Fields said about water:

“You can’t trust water: Even a straight stick turns crooked in it.”


Allison A. Bailes III, PhD is a speaker, writer, building science consultant, and the founder of Energy Vanguard in Decatur, Georgia.  He has a doctorate in physics and is the author of a bestselling book on building science.  He also writes the Energy Vanguard Blog.  For more updates, you can subscribe to Energy Vanguard’s weekly newsletter and follow him on LinkedIn.


Related Articles

Be a Controlling Building Enclosure Control Freak with Control Layers

You Don’t Need a Vapor Barrier (Probably)

Meeting ENERGY STAR’s Water Management Checklist


Photo credits: Both photos used with permission of Eric George of The Building Performance Group in Louisville, Kentucky.


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This Post Has 12 Comments

  1. Great! Let’s wrap a spong
    Great! Let’s wrap a spong around a soggy mess, then wrap it in building paper to slow drying more. 
    Obviously the building owners hired a knowledgeble expert to assess the problem and oversee the work. 
    Lesson learned. ?? We’ll see. 

  2. I think blaming the owner is
    I think blaming the owner is a bit misguided. eg- Is a WRB not required in Kentucky? Who did the drawings and specs? Who approved them? Was there not housewrap ordered and on site? Who installed the siding? Why didn’t the building inspector catch this?  
    It was for sure a bad repair job, but there are many people that should have prevented this from happening. Homeowners should not have to know this stuff. It is up to the industry as a whole, and we’re blowing it.

  3. Geoff H.:
    Geoff H.: Yep. 
    Jesse M.: I totally agree. I just went back and read the article, and I’m not sure what caused you to come to the conclusion that I was blaming the homeowners. As you state, the blame should be placed on the original builder and the building inspectors. The blame for the bad repair in January is on the contractor.

  4. Apologies Allison,  
    Apologies Allison,  
    My comment about the owner’s responsibility was a response to Geoff, but I see his point as well. I think we are all upset at the repeated failures here.  
    Great article highlighting some serious issues.

  5. I saw this same type of
    I saw this same type of installation about eight years ago and asked an acquaintance who worked with a major vinyl siding installer and asked, where the moisture barrier was. He became defensive and said the siding was the barrier. But I said the laps are not moisture tight. Conversation ended. No telling how many thousands of homes have this condition in this Climate zone 4. Thanks for posting this article.

  6. Great! Let’s wrap a spong
    Great! Let’s wrap a spong around a soggy mess, then wrap it in building paper to slow drying more. 
    Obviously the building owners hired a knowledgeble expert to assess the problem and oversee the work. 
    Lesson learned. ?? We’ll see. 

  7. BTW — There are hundreds,
    BTW — There are hundreds, maybe thousands of this situation -at vinyl siding spplied directly over OSB in and around Atlanta, GA. I asked site staff about it and they did not see a problem. Often those window/door openings were not flashed either. 
    So much work to redo! Good news is that there is s lot more money in re-work, repair, and insurance claims than in arguing the point up front. 🙂 

  8. Rick: That
    Rick: That’s one of the first things I noticed, too. 
    Blake T.: Clearly, not enough contractors understand moisture. 
    Geoff H.: Is this something advocated by the vinyl siding industry? 
    Maureen: Glad to hear you did it right!

  9. I don’t think the vinyl
    I don’t think the vinyl siding industry would be advocating application over OSB, or any other surface, without a drainage plane. However, I do think that many sales and installation crews are uninformed. I have spoken to sales people at trade shows that clearly think vinyl is the answer for all exterior ailments. I have also seen vinyl siding installed over old siding to refresh the home’s appearance, with no indication that anything was done underneath, except maybe to wrap the house in “high efficiency foam insulation” which means a 1/16? or 1/8 inch flexible foam accordion-fold product. That at least might make a partial drainage and/or air (wind more likely) barrier.

  10. Great article! I think this
    Great article! I think this is a combination of contractors not understanding building science, not hiring a building science expert (HERS Rater, for example)at the planning stage, contractors not understanding how to fix the problem and a homeowner paying the ultimate price.  
    Its scary to think about how many homes out there have similar problems.  
    The bottom line is whether you are a homeowner, builder or re-modeler, you need to hire a building science expert. The cost is minimal when you think of the problems you can be preventing.

  11. I’ve replaced my share of the
    I’ve replaced my share of the old recalled particle board & OSB siding, and there’s no easy way to correct the issue. I’ve seen furring strips installed over the old siding or sheathing, which provides an air space between old and new siding/sheathing and also serves as a nailer. The air space helps dry out any moisture that does make it inside the wall, but handling windows and doors is a challenge. 
    A comedy [or tragedy] of errors… I feel for the homeowners.

  12. Sometimes I have this strange
    Sometimes I have this strange feeling that there are cases where government intrusion into our lives is actually not that bad. Do I need therapy? 
    The SIP example shows that just because you chose SIP does not mean you’re a knowledgeable contractor. For this house, inspector failure at construction time for sure, but maybe there should be inspections required for exterior repairs? 

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