[bvac]

I took down my plaster ceiling in order to, among other things, install recessed lighting.

The joists are in good condition, there was practically no dust or debris, none of the joists were rotted, cracked, notched, or otherwise in need of repair. Some are slightly uneven with the rest. On an exterior wall near the chimney it appears that some efflorescence made its way to the wood, but I think the problem has been taken care of. I did find a paper bag full of L hooks between one of the bays that probably dates back to the 20s, so that's cool.

The attic above is insulated at the rafters, and the only layer of flooring is ⅝” doug fir tongue and groove. If I finish the attic in the future, that’ll come up so a proper sub floor can be put down, so I can insulate then if necessary.

So, is there anything I should do before closing it up with sheetrock? Should I add more bridging or blocking? Insulate the top plate with rigid foam? Just leave everything alone?


Thanks in advance!

 

[rjniles]

Insulate with unfaced batts. Install firring strips and shim to level. I like to use 1 by 4s to make installing the drywall easy. Use the largest drywall you can find to eliminate butt joints. Use a drywall lift.

 

[carpdad]

The first photo seems to show a cripple wall over the window and the joists are resting on it. That does not replace a load bearing beam/header.
The existing joists may not be strong enough if you want a living space on it later. What is its size and the span? You alone walking on it is not a test.
If the joists are not even (plaster can fix it but not with a drywall), you want to even out the plane then put your lights.
The future work may need additional electric. It doesn't hurt to put a chase somewhere.
The leak can't be dismissed. If you're guessing, you must have somebody look at the chimney. Cricket, capping and flue conditions, flashing - these must be in order before you close up.

 

[bvac]

Not evident from the photos is that the header above the window consists of 2 @ 2x4s, and a 4x4 top plate rests on the cripple wall. It would probably be ideal to have a full 2x10 header in place, but I can make that change before I finish the attic space (which is a few years away) -- probably when I go to replace the windows (which I hope to do within the next year).

The joists are 2x10 16" OC, and the span is a frightening 15 feet, which is about the same as the first floor except those joists run from the main carry beam to the brick foundation. If I had to sister the joists, is that something I could reasonably do from above when I pull up the floor?

I'm going to run a line tonight to see how uneven the joists are, and see what I can do to get them planar. I'm hoping that I won't have to run furring strips across the entire ceiling.

I'm 99% sure the water problem has been taken care of. The chimney has been relined, repointed, and reflashed, and I've put down a new roof down to the decking, and new gutters. It's rained a few times in the past week and I haven't seen any evidence of moisture. That said, I'll give it another look before putting the ceiling up for sure.

The first photo seems to show a cripple wall over the window and the joists are resting on it. That does not replace a load bearing beam/header.
The existing joists may not be strong enough if you want a living space on it later. What is its size and the span? You alone walking on it is not a test.
If the joists are not even (plaster can fix it but not with a drywall), you want to even out the plane then put your lights.
The future work may need additional electric. It doesn't hurt to put a chase somewhere.
The leak can't be dismissed. If you're guessing, you must have somebody look at the chimney. Cricket, capping and flue conditions, flashing - these must be in order before you close up.

 

[carpdad]

Reinforcing the joists later may become impossible with the light wires. No regrets if you do it now. Also, header needs supporting studs (jack/king). At least install the studs now and make sure they are supported to the foundation. Check the joist bays underneath and fill them in for a continuous support.
BTW, the joists must attach to the header. I'm not sure how you'll do that later.

 

[Gary in WA]

Have you checked the span tables for your Doug. Fir joists, may not require sistering, check local AHJ; http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_5_par020.htm?bu2=undefined

IMO, add rigid foam board to the rims now, much easier than on your knees later, from above- and may not be able to remove all the floor decking boards under the exterior walls- unless a complete remodel.

Gary

 

[bvac]

Well, I guess diychat decided to not send me notifications when there are replies on this thread anymore..
@carpdad see attached image.. I was thinking I could remove the cripple studs and replace it with a 2x10 header, which would be supported by the existing jack studs (there may be two jack studs on each side, I haven't opened the wall to see yet), and in turn would support the 4x4 plate above it, and the joists which rest on the 4x4. All of the joists are notched like 1/4" and toe nailed into the 4x4. What else would have to be done to make the header carry that load?

It dawned on me that this entire room is cantilevered over the first floor by a foot. How is load transferred in cases like this? I'm not sure how the wall beneath it is framed. Hopefully this doesn't complicate making the attic a livable space down the road.


@Gary in WA good idea to insulate the rim joist while I have access. Is that worth doing even if no other wall in the house is insulated?

 

[Gary in WA]

That wall has horizontal projection as well as a rim joist, while it is open- insulate with foamboard; http://buildingscience.com/documents/insights/bsi-005-a-bridge-too-far

http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_5_par024.htm

Gary