# Replacing T1-11 siding with fake board and batten



## Kory Beam (Nov 15, 2014)

Hi all! Have a few questions about replacing the siding on my small mountain cabin.
A previous owner installed T1-11 horizontal... I guess to mimic shiplap. It was nailed up over the original siding. They used a few screws and mostly roofing nails. Lots of caulking. It lasted... and was water tight. 

This is a box car style cabin in the mountains of Southern California. The original (1972) siding was fake board and batten. So... felt over the studs, plywood panels over felt, and battens at the abutting joints and spaced in-between. Somebody just removed the battens and nailed this T1-11 over the original ply. 

I want to basically do a nice looking fake board and batten... similar to the original. I have a neighbor who has nice board & batten looking siding. It looks like they have ply panels with battens. Stained/sealed. I want to do pretty much exactly what they did. My walls are only 4 feet tall... so not nearly as big a job as theirs.

I removed the T1-11 panels and I am left with the original ply siding that was under it. I believe it is 7/16. It won't win any beauty contests. Not bulging or completely shot... but it has obviously seen some years.

Wondering how I should deal with the original ply. Should I just go over it, leaving it as if it were sheathing? Yank it to felt & studs and start new? The felt is beneath the ply, over the studs. The insides of the walls are great. No water intrusions. Original exterior ply/siding just looks like heck from years of exposure.

I am attaching pics of the current state, showing the original ply, and also the neighbors house that I wish to mimic. Also a shot of the inside, so you can see how these low walls work on the inside. Appreciate any advice/info!


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## Kory Beam (Nov 15, 2014)

Another view of the original plywood siding. You can see that the poured deck (I think that is what it is called) is flashed to the bottom of the original panels. The T1-11 was sandwiched on top. 

Any ideas on whether to just go over the original siding as if it were sheathing, vs. removing it and re-sheathing and then doing the plywood board & batten over that?


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## kwikfishron (Mar 11, 2010)

Kory Beam said:


> Any ideas on whether to just go over the original siding as if it were sheathing,


That's what I'd do if it's in solid shape. Just replace it on a as needed bases and save what you can if not all of it.

Go over the existing with housewrap (I use roofing felt) before the new siding. 

Consider using Hardie Panel instead of wood, it's a fiber cement panel that comes in sheets just like plywood but wont rot. You're situation in a perfect candidate for the Hardie.


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## Kory Beam (Nov 15, 2014)

Thanks, kwik!

You would still go over existing with felt, even though there is felt beneath the existing? No issues with double felt?

Aprreciated!


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## Kory Beam (Nov 15, 2014)

*Re: T1-11 over sheathing question*

Here is a pic from the back side. You can see how they put up the T1-11... on its side. Guess they were trying to do the shiplap look. 

Anyhow, two of these sheets on the back side (16 feet) have been affixed with tar adhesive to the original ply. So those two lengths have to be taken to the studs. Original ply below it (nearest to ground level) has also been tar'ed, and must be replaced. I think it was shot from exposure to snow, so it was just tar'ed over.


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## beenthere (Oct 11, 2008)

Merged threads.


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## Gary in WA (Mar 11, 2009)

IMO, leave the original felt/sheathing for wall lateral shear flow. Remove the tar, if full coverage as that is acting as a vapor barrier, allowing drying to inside only. Though it may work fine as you have no sign of interior water damage/mold on drywall surface. Cut the sheathing to get better (metal) flashing for the bottom 4" of the wall. on the poured slab. 

Adding H-board is fine but remember it is a water reservoir siding in that it holds/stores water/moisture and with just tar paper behind the sheathing underneath could easily stay saturated- especially if insulation has a vapor retarder facing; http://buildingscience.com/documents/information-sheets/reservoir-claddings 

Gary


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## Kory Beam (Nov 15, 2014)

Thanks, Gary. The tar was mopped onto the original ply (siding) on the back of the house, and they must have nailed up the sideways T1-11 while it was wet. That yellow T1-11 is basically adhered to the original ply underneath it. It will all have to be removed to the felt. I figured that since I have to remove it to the felt... I may as well re-sheath with 1/2" ext. ply over the felt/studs and then put the plain 5/8" T1-11 over that. Then I can do the fake board and batten, with battens at whatever spacing, since there will be plenty of plywood/sheathing base for a batten nail to bite into. Talking about the back of the house here. Otherwise, I could just nail 5/8 plaint T1-11 over the felt/studs. Just not sure if that is enough thickness/dimension for exterior cladding on a home (small cabin). That is how it was originally built.

On the front side, there is a metal flashing in place that wraps up and nailed onto the plywood... it is underneath the fiberglass top layer that is seen wrapping about 4 inches onto the ply face. That plywood siding looks okay... but is a little thin and somewhat brittle/weathered. Would not trust it as a solid nail base. It also needs to be nailed up flush to the studs, as it has pulled away a little. Original fasteners are staples. Might just be easier to replace? 4 foot tall wall, so every 8 foot sheet will cover 8 feet of wall length. 

Not interested in Hardie, as I really want to do the stained board and batten look, rather than solid color/paint.

The deck is some weird textured deck that has a fiberglass like top layer... and painted. Needs a new coat of restore or similar deck paint.


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## Gary in WA (Mar 11, 2009)

As you will see the insulation installed, check for an air gap behind the FG batt, if used. You may need to install more fibrous insulation as the bat has a tendency to shrink over the years, IMO. Junk the old building paper as new needs to be installed because usually the tar is non-existent and doesn't retard the moisture entering from outside. T1-11 always has been a shear sheathing, no other sheathing/braces are required. Unless you want the added thickness for 12" on center batten spacing, as said. Just re-nail securely. 5/8" 303 siding (T1-11 without grooves) is structural, have links if needed.

Gary


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## Kory Beam (Nov 15, 2014)

Thanks again, Gary. Great tip on the insulation... though I did replace the old FG when I rebuilt the inside. I guess I went backwards. Did the interior... saved siding for last. I did have the roof done as soon as I bought it,

Will certainly use new felt. If I did sheath with 1/2" over studs - and then the 5/8" 303 siding on top of that... should I place the felt directly over the studs, or should it go over the 1/2" sheathing between the sheathing and T1-11? Seems like felt over sheathing would be correct. Would it matter?


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## Gary in WA (Mar 11, 2009)

Yes, a WRB should go directly under the siding and drain down in front of any metal flashing. The metal flash/303 goes over the sheathing. If snow problems, metal flash 6-8" above the slab and stop the 303 1-1/2" below that to keep constant moisture from end wicking the siding. Caulk under the "L" bend touching the slab. Sticky wrap the metal flash top edge to the sheathing (before 303) so when WRB (paper) gets wet, capillarity won't drain it behind the flash (wetting the sheathing) due to contact because of two elevation surfaces. Optimum; use 2 layers paper, OR rainscreen the 303 on furring strips as the sheathing is already providing the shear resistance. Back/end grain edge prime the 303 (either case), prime the sheathing face for best protection.

Gary


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## Kory Beam (Nov 15, 2014)

Gary, you are an absolute stud. Thank you!


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