I hope some kind soul can help. There are millions of bits of info on the internet but I’ve yet to find a solid answer to my question in my specific situation. I will state my general question first then some background.
General Question: What is the best strategy for installing a SYP, 1×6, T&G ceiling in my new home (renovation from a complete gut of my 116 year old house).
Background and details:
The home is 116 years old but this may as well be new construction as I have completely gutted it. New systems, new siding, new insulation…only thing that is original is the shape of the home and the framing, which actually has significant modification.
Below the ceiling will obviously be living space. There is an attic above the ceiling. The ceiling is flat and 12′ high. I am planning to use blown in insulation in the attic.
My ventilation in the attic is soffit vents and ridge vents.
I was planning to install the T&G directly onto the ceiling joists (no drywall). I have checked with my building official and this is fine by them.
Home is in a northern suburb of Atlanta, Ga.
Concerns:
I’ve read that I should be concerned about air infiltration and that I need an air barrier (but not a vapor barrier) above the ceiling. If I do not do this, I will loose precious energy which will just slip right through that ceiling assembly. Lots of posts say to install a taped but unfinished drywall ceiling, which is a significant effort and expense (this wood ceiling is just about everywhere in a 2,700 SF house). I’d love to hear any learned opinions on this.
I’ve read that I should finish both sides of the plank. Finishing one side and not the other seals one side (the in-side) from humidity while the “up”-side is un sealed and in the attic. If moisture (humidity) gets to the “up” side it will swell causing the board to cup. But I’m wondering, the “up” side seems to me to be technically inside the home also, since it is under the blown in insulation. Is this really going to be an issue? Sealing the “up’ side is a huge job since I have 400 16′ boards to work with. Again opinions are welcome please.
Right now I have all the boards stacked with spacers in a large room in the house, under a makeshift plastic tent with a dehumidifier, in order to extract as much moisture as I can. Before that, the boards were at 15% MC. I am striving to get them down to 8% or so.
My plan was to install the boards over the course of a week, without sealing the “up” side and without an air barrier. Once up, that will give me a “floor” on which to blow in my insulation. Once insulation is in, I’ll turn on the AC and furnace, which will control the humidity in the house. Then I will roll on a coat of poly. Alternatively, I was thinking of just using a wood oil, like Danish Oil or something, which I think will look great but may not be long lasting.
I am a novice and would deeply appreciate any feedback from those craftsmen with experience in this type of installation.
Thank you!!
Replies
Tyvek-type building paper, either stapled below the joists before the T&G goes up or laid over them after the ceiling is in place, will prevent air infiltration (and also keep the insulation from sifting through the T&G joints).
And, NO, Tyvek is NOT a "vapor barrier".
That's a great suggestion! Thanks DanH,
I will look into that. Everything else seem ok with my install plans? Ron
Do what Don says.
I have 2x6 T&G for 2nd floor, MDF above with carpet over that.
Now, here is your kicker even if you do put down a barrier - you WILL get some sawdust drop thru for 3-4 years, unless there is never any generated in your attic. Of course, we had lots of sawdust on 2nd floor when finishing there. Vacuumed twice before MDF.
Even 28 years later in 2001 eathquake we got a new dose of traces of sawdust.
So, you should pay attention to not generating any sawdust above the T&G.
Without the barrier, you will have insulation strands sifting thru for the rest of your life.
Junk yes I am hearing that from others as well. The tyvek solution seems fairly easy and inexpensive.
Thanks so much for the feedback!
If I add the tyvek, would you have any concerns about the rest of my installation plan? In other words would you do it differently (and why)?
Ron
go with a ceiling backer!
You have ceiling joists (as opposed to trusses). Good. You have good attic ventillation. Good. You want to use SYP boards. Not so good.
My strong recommendation is that you start with some kind of wood substrate on the ceiling to which you attach the T&G boards. If you check out an article I wrote for my website, "A Remodel with a Greek Theme" (froscarpentry.com) you will see that my substrate of choice was 1/2" plywood. This allowed me to fasten 3/8" thick x 4" wide knotty pine boards wherever I wanted. Plywood provides a stable base. Nailing your boards directly to the ceiling joists is not the best idea.
SYP is not, in my opinion, the best ceiling board to use. SYP is less stable than, say, pine or cedar. T&G "Car Siding" is typically made from pine boards. Also the stability of the ceiling board is related to its thickness.
Finally, you want to seal your boards on all edges, cut ends, backs and fronts! There is no other way to ensure a lasting, good-looking product.
Mel
T&G ceiling
Wynn,
get rid of the de-humidifier! Leave the material stacked and stickered as it is, let it sit for
10 days or so and you will be fine. Let the wood acclimate to the building MC before you install it.
Install the tyvek with the face facing the attic (upside down so to speak). Pre-stain ALL the
material on All sides.When you do the install, keep a small container of stain near your cut-
station and finish all the cut ends before installing. Use square-drive trim head screws to
"blind screw" the boards. Pre-drill a pilot hole!! I assume you are "blind" fastening.
Good Luck
Geoff
It makes no difference which side of the Tyvek faces out.