[Leah Frances]

I have a room below an unfinished attic space that currently has a floor installed in it. Between the ceiling joists are unfaced insulation batts. The former plaster ceiling had to come down. This is a 200 year old house.

- I've been reading an believe I need a vapor barrier. Am I right?

- can I do the foil bubble stuff to add some additional R value? Can I just install the tin ceiling up against the foil? I'm talking about code issues here. I'm sure I 'can' do it. The question is: 'should' I do it.

- I am talking about a REAL tin ceiling, not fake tiles. The tiles interlock (overlapping each other with a 'friction joint' by 1/4 inch) and are screwed to the joists. They are listed by ASTM E 176 and 84 testing as 'CLASS A' or 'TYPE I'. The foil stuff I'm looking at is also rated CLASS A.

Thoughts?

 

[jklingel]

True vapor barriers are being shied away from, in all but the coldest spots in the country, and even there they are not always being used. I will not have one in my new house, though the one in my 30 yr old house seems to be working (as are 100,000 others installed between 1980 and now). Check your code yourself, and see if it says "vapor retarder of one perm or less" or "vapor barrier". Air sealing and vapor retarding is the norm now. Whatever you do, air sealing is #1. Were it mine, and code allowed (I bet it does, but check) I would install rigid EPS foam and caulk/tape the seams.

 

[Leah Frances]

True vapor barriers are being shied away from, in all but the coldest spots in the country, and even there they are not always being used. I will not have one in my new house, though the one in my 30 yr old house seems to be working (as are 100,000 others installed between 1980 and now). Check your code yourself, and see if it says "vapor retarder of one perm or less" or "vapor barrier". Air sealing and vapor retarding is the norm now. Whatever you do, air sealing is #1. Were it mine, and code allowed (I bet it does, but check) I would install rigid EPS foam and caulk/tape the seams.

Doesn't EPS foam have to be covered by drywall? Or is the tin ceiling the same effect? I'm all about doing what is easy, so long as it is right.

I'm referring to fire rating here.

 

[Ron6519]

I wouldn't install the tin ceiling to the joists. I'd put up a sheetrock ceiling on a leveled plane, install 1x3 boards in a grid pattern and install the tin on that. Put a vapor barrier up before the sheetrock.
Ron

 

[jklingel]

Doesn't EPS foam have to be covered by drywall?

** Dunno; check code. People spray foam in attics all the time, and I don't think they rock over them in an attic. I will argue against the vapor barrier; read on buildingscience.com. Vapor open, air tight.

 

[Leah Frances]

I wouldn't install the tin ceiling to the joists. I'd put up a sheetrock ceiling on a leveled plane, install 1x3 boards in a grid pattern and install the tin on that. Put a vapor barrier up before the sheetrock.
Ron

Yes, but do I have to? I mean in respect to the code. I don't see any benefit in sheetrocking the ceiling if I don't have to. Just seems like adding additional layer, cost, time, and effort. If I'm required by code, then I'll do it. But otherwise, what is the justification for adding the layer of sheetrock?

The bottom of the joists are level, the tiles do no require strapping, they are designed to be attached to 16 inch center joists.

 

[Ron6519]

Yes, but do I have to? I mean in respect to the code. I don't see any benefit in sheetrocking the ceiling if I don't have to. Just seems like adding additional layer, cost, time, and effort. If I'm required by code, then I'll do it. But otherwise, what is the justification for adding the layer of sheetrock?

The bottom of the joists are level, the tiles do no require strapping, they are designed to be attached to 16 inch center joists.

I would put a layer of a non combustible surface over the top of wood joists, especially in a 200 year old house.
It's just common sense.
You'd have to check if it's code.
Ron

 

[Leah Frances]

I would put a layer of a non combustible surface over the top of wood joists, especially in a 200 year old house.
It's just common sense.
You'd have to check if it's code.
Ron

Yeah local information about code is the best.....

Durn holiday weekend makin' my life harder not easier. :laughing: Guess I'll have to work on something else 'til tuesday.

Thanks for the advice.

 

[Leah Frances]

I would put a layer of a non combustible surface over the top of wood joists, especially in a 200 year old house.
It's just common sense.
You'd have to check if it's code.
Ron

So, I'm digging around and trying to find info about non combustible. I THINK....Sheetrock only qualifies as limited-combustible considered non combustable and from my reading the tin ceiling should also fall into that category for Building Code because of it's rating.

All of this is qualified because I'm not even remotely comfortable with Building Code and NFPA rules. So, yeah, I should call my local Building Code Enforcement folks. :whistling2:

 

[Gary in WA]

Code doesn’t require one if in Zone 4: http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec001_par001.htm

R-38 is required: http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec002.htm

No vb: http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_6_sec001_par003.htm

+1/4” plywood is also acceptable without drywall backer; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_7_sec002_par017.htm

The poly, in my opinion, would trap the warm moist air from below to condense on the tin and rust. You want it to reach the attic (hopefully vented) to escape there.

Check locally…..

Gary

 

[Leah Frances]

Thanks Gary. Great links. Lots of good info.