Proper panelized wood siding termination

[Ross Neag]

Does someone have an image/detail/pdf of proper 4x8 T & G wood siding base detail? The base edge terminated over brick veneer and the base on most panels were buckling. Common sense tells me I should see a base flashing with drip edge but good documentation would help. Ten year old house. TIA...

[BARRY ADAIR]

Publications Featuring APA Rated Siding | APA - The Engineered Wood Association (http://www.apawood.org/level_c.cfm?content=pub_sid_libmain)

[Ross Neag]

Thanks Barry, had to wade through a bit but found what I was looking for.

[Vern Heiler]

Thanks Barry, had to wade through a bit but found what I was looking for.
Ross, I have never seen what you were describing. Would you point me to it?

thanks

[Ross Neag]

Vern,

It's just a basic z flashing that you would see at any horizontal junction. I actually saw only one reference through APA's numerous pdfs (sorry, don't have handy for you). Since I don't know the manufacturer I had to generalize about best practices.

[Gunnar Alquist]

Ross, I have never seen what you were describing. Would you point me to it?

thanks

Vern

This might be what you are looking for.

http://www.apawood.org/pdfs/managed/A530.pdf?CFID=21736617&CFTOKEN=38091857

[Vern Heiler]

Vern

This might be what you are looking for.

http://www.apawood.org/pdfs/managed/A530.pdf?CFID=21736617&CFTOKEN=38091857
Thanks Gunner. Between panels is the only way I've seen Z' flashing used. Never seen it used at the bottom of the wall. I don't see how it would work any better than a good coat of paint. Actually looks like it would cause more trouble by wicking than to just let the water drip off the bottom end.

[chris mcintyre]

Thanks Gunner. Between panels is the only way I've seen Z' flashing used. Never seen it used at the bottom of the wall. I don't see how it would work any better than a good coat of paint. Actually looks like it would cause more trouble by wicking than to just let the water drip off the bottom end.


I agree.

I have never seen flashing in a real world application, I have only seen it as pictured in the OP.

I think Ross raised a good question and this is as close as I could find to a manufactures requirement.

From:http://www.gp.com/build/DocumentViewer.aspx?repository=bp&elementid=3196

[Ross Neag]

If the sealant in my original pic wasn't there and the siding panels were well primed and finish painted at the base I bet we would have this thread moving. However, based on viewed field conditions, this wouldn't be a difficult retrofit and I also don't know how much the panels terminate over the brick (1", 6" ??). I'm confused by Vern's comment that "I don't see how it would work any better than a good coat of paint. Actually looks like it would cause more trouble by wicking than to just let the water drip off the bottom end."

Moisture can easily wick off of a square cut base and up the backside, especially for those base ends whose paint is either beginning to or in the end stages of failure (failing nonetheless). As the wood pores open it would only accelerate. I'm doubling down on flashing.

[Bill Wieczorek]

Had a home for for 20 years that had the same siding you described, it overlaped the foundation by 1.5 inches. No flashing, the home was built in the 70's. I had no problems the base of the siding was just fine. The next owner put horizontal siding over the original.

[Terry Beck]

I agree with Vern and others. Because the siding overlaps the brick veneer, I don't see any way flashing would be of benefit in this particular application. Around here, we call this siding material T1-11 - probably the cheapest sculpted plywood siding available, and notorious for being susceptible to water damage if not kept well sealed with paint (front, bottom edge, and back). The T1-11 probably overlaps most of the top course of the brick veneer. You would like to make sure there is some sort of house wrap or other moisture barrier behind the T1-11 that extends down to the bottom edge of the siding (separates the siding from the brick or concrete foundation).

I don't see the source of the last pic posted. Here is an image from page 41 of the APA guide. There is no flashing shown in this picture.

[Door Guy]

I agree.

I have never seen flashing in a real world application, I have only seen it as pictured in the OP.

I think Ross raised a good question and this is as close as I could find to a manufactures requirement.

From:http://www.gp.com/build/DocumentViewer.aspx?repository=bp&elementid=3196

If this is at at the foundation level, than I have never seen flashing in a real world application at the point either. Yes moisture can wick up the square cut, but most of the water will drip off and it does appear one course of brick is covered. Separate the wood from brick with vapor barrier should be all that's needed.

[Christopher Ueland]

Hi Ross,

Buckling at bottom of T-1-11 likely not due to lack of Z-flashing.

More likely causes:

Lack of adequate priming/painting of bottom edge of T-1-11 before it was made to look pretty.

If brick veneer is at foundation wall and close to grade, splash up might also aggrevate or be the cause.

If brick veneer is at wood framing, unclear how framing works; possible hidden flashing above brick draining toward back of T-1-11.

Though caulk looks newer, it might have stopped moisture from draining behind siding. In MN, generally undesirable to caulk joints in this type location where moisture could be trapped above caulk.

More overall view of location of buckling might help eliminate some possible causes (e.g. Is buckling localized? Is this at foundation? A window above? Gable end of house?, etc.).

Since can't be sure of cause (based on close up photo), this is an example where risky for HI to advise on how to fix.

Everyone have a Merry Christmas holiday.

C. Ueland

[Ross Neag]

To all,

This was at the 1st to 2nd floor transition, 12' above grade so no foundation splashing. Agree with all, without some disassembly we have no way of knowing installation methods besides, presumably, improper.