CountryPlans Forum

Plans Support => Plans Support => Topic started by: MikeT on July 08, 2008, 10:08:14 PM

Title: t1-11 best installation practices
Post by: MikeT on July 08, 2008, 10:08:14 PM
I finally got my shearwall inspection approved on my VC (on the Oregon Coast), so now I can cover the exterior.  I plan on using 30# tar paper over the plywood.

I have a good amount of cedar shingles that I plan on using, but I also plan on using T1-11 that I got a good deal on ($20/sheet for 1/2" thick and 4" panels--never been outside--brand new).  My question concerns the best way to install this stuff:

1. Should I run a small furring strip over the tar paper to create an air gap?  I am on the Oregon Coast, remember.

2. Between the sheets on the ends I probably should use some Z flashing, correct?

3. And caulking at the edges?

4. Stain or paint (does one hold better than the other?)

5. Anything else?

Thanks,
Mike
Title: Re: t1-11 best installation practices
Post by: muldoon on July 08, 2008, 10:23:07 PM
I am outside my field of expertise on this so hopefully someone else will chime in if I get anything wrong.

My house is sheathed in T111 as well, and over the years I have replaced a bit of it as needed.

1. Should I run a small furring strip over the tar paper to create an air gap?  I am on the Oregon Coast, remember.

I would say no based on what I have seen and done.  I live on the gulf coast, where high heat and very high humidity are the norm and have not had any problems with this.  I have 30# tar paper under the T111 and thats it.

4. Stain or paint (does one hold better than the other?)

Stain works, but the t111 soaks it up.  If you go this route, I would not bother with the roller but instead pick up a cheap 5 dollar "bug sprayer" at lowes.  The plastic kind you pump up.  Apply the stain and or thompsons with it.

For my house, I use "kilz" primer, then a good quality exterior paint and am happy with it.  For what it's worth, I used behr from home depot with good success. 

5. Anything else?

I would be wary of the "splash" edge.  You don't want the wood anywhere near the ground as there's where you see trouble.  If you can keep your bottom edge far away from the ground - at least 6-8 inches, preferably 12-18 inches you'll do fine.  The splash from rain really seems to beat it up over the years.  It also is a wood and will wick if in direct contact which will rot it out very quickly.  Give it room to drain and dry and you'll likely be happy with the results.
Title: Re: t1-11 best installation practices
Post by: glenn kangiser on July 08, 2008, 10:31:01 PM
The #30 felt is good as it will wrinkle and drain, but the furring for the rain screen wall effect is added insurance.

My dad has had z flashing over his for years - keeps the tops from coming apart.

Stain on the Cedar or redwood.  Paint will hold pretty good on most other woods from my experience -- but -- I haven't lived on the coast in years --
Title: Re: t1-11 best installation practices
Post by: John Raabe on July 08, 2008, 11:30:59 PM
Here are some notes I found that might be of interest:

Make sure that you get plywood T1-11, not the oriented stand board (OSB) imitation. (I have seen such OSB siding expand just like the LP siding). T1-11 siding needs careful installation and proper use of "Z" flashing between rows of material. A good paint or stain will last for a long time. Light-bodied stain may have to be re-done every 3-5 years. Medium-bodied stain will last longer. T1-11, which is primed and painted, should not require a re-coating for 15 years. Also, Prime, paint or stain all edges prior to installation. When the stack arrives on site, get the roller out and go to town on the stack. With every cut someone needs to be there with a small roller and coat the cuts. I have found this to work very well with any plywood siding combined with proper caulking.

You might consider running this siding vertically (painted) with stained shingles on the gable ends above a flashed trim board at the top of the T1-11. The above note about caulking means at penetrations. You should not caulk or glue the butt edges (Z-flash these) or T&G joints (these need to drain). Leave 1/8" or so for movement.
Title: Re: t1-11 best installation practices
Post by: PEG688 on July 08, 2008, 11:52:50 PM


  Here's what I'd do if forced to use T1-11 in the situation your in .

  But first one question if it's 1/2" thick I'd think it was T1-11 blanks , NO grooves, is that right?

 

If so I'd paper over your OSB sheathing with 15 lbs felt not 30 lbs,

30 lbs is for roofs , 15 lbs is made for sidewalls .

I'd "fir out" the gable ends with some rippings of the T1-11 so that I could over lap the gable end T1-11 OVER he lower pieces by 2".

Yes this leaves that lower  ply edge exposed BUT it's exposed on the bottom side of a vertical wall , when you paint or stain pay proper attention to that edge to fill it with what ever finish you  use , I'd say stain would be best for both the Cedar shingles and the T1-11 . A solid body or semi transparent stain OIL  based stain.


The really sticky places to attend to are around windows , IF you want  or expect to have any wood trim around the windows and doors the T1-11 is even more complicated to detail properly. So I consider that in your dilemma as well. 


So to recap IF it's 1/2 thick and has grooves it garbage , fit only for out building , barns etc.
It's PITA to flash / install properly IF and window trim is used along with T1-11.

You've put to much effort and $$ into your place to save a few bucks with cheap siding , IMO it will be a mistake to use it.  BUT if you must watch the details , "think like rain" and lead it out when and where ever possible , and caulking IS NOT a substitute for FLASHING!   

Title: Re: t1-11 best installation practices
Post by: r8ingbull on July 09, 2008, 07:25:09 AM
Quote from: muldoon on July 08, 2008, 10:23:07 PM
4. Stain or paint (does one hold better than the other?)

Stain works, but the t111 soaks it up.  If you go this route, I would not bother with the roller but instead pick up a cheap 5 dollar "bug sprayer" at lowes.  The plastic kind you pump up.  Apply the stain and or thompsons with it.

For my house, I use "kilz" primer, then a good quality exterior paint and am happy with it.  For what it's worth, I used behr from home depot with good success. 

Make sure you get all 6 sides of each piece, especially after cutting.

Is your T1-11 pre-primed?  If not I would use a high quality stain (graham, sikkens are the best around here).  You can use a roller or the chemical sprayer.  Just remember that all stains need to be "back brushed".  After you roll or spray the stain you need to go over it with a brush and work it into the pores of the wood.  The brush helps open the wood up and absorb more stain.

If it is pre-primed, or you can't back-brush, or you can't get a good stain (not HD or Lowes brands, head to the paint store), I would use paint.  You don't need anything fancy for the primer.  Kilz exterior works good and is cheap.  The store brand oil based primers should work, and are cheap.  I would use an oil based primer for sure.  Pre-primed, give it one coat of primer.  If it is bare, prime until it quits soaking in the primer.  Two coats of exterior latex and it's ready.

Also, anytime you are dealing with a pre-primed product like a door or T1-11, it MUST be primed again.  Primers have a set time window that they need to be top coated within.  The primer hardens and the paint won't stick.  Usually 14 days.  Distribution of the product and installation takes too long.