Replies

1. 
   calvin | Dec 11, 2007 04:18am | #1

   Is there absolutely no way you'll stuff anything else up there

   like just a couple things.............?

   Recently we installed a couple lvl's under the undersized joists in a garage because the sag had gotten to a couple inches.  And these 2x6's had already been jury-rigged with a truss configuration attachment to the rafters and ridge. 

   Course the triple 2x6 "beam" that was originally installed at mid span (20ft long) might have been pulling it down.  These folks and previous owners used the garage "attic" for storage.

   No future room, no storage-around 16 ft max.  Probably should install a hog trough/stiff back at mid span which should stiffen it a bit.  A 2x6 that long will sag cuz of gravity over time. 

   A Great Place for Information, Comraderie, and a Sucker Punch.

   Remodeling Contractor just outside the Glass City.

   http://www.quittintime.com/

    

   
   

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   Edited 12/10/2007 10:18 pm ET by calvin

1. 
   jdom | Dec 11, 2007 06:12am | #4

   Thanks, Calvin. You're right. Ideally, I'd like to use the area as storage too. I'll keep your ideas in mind.

2. 
   MikeHennessy | Dec 11, 2007 04:18am | #2

   Don't know what the numbers work out to, but I wouldn't do it without adding some ties from the ceiling "joists" (probably rafter ties) to the joists near the peak to support the center of the span. And I sure wouldn't plan on storing anything on them. I'd also probably put up batts from below before the DW, and use 1/2" max.

   Maybe somebody can calculate the permissable load for a 20' 2"X6".

   Mike Hennessy
   Pittsburgh, PA

3. 
   RalphWicklund | Dec 11, 2007 05:56am | #3

   What's the span the other way?

   Knowing the span you could mount an LVL or two perpendicular at midpoint, jack up the ceiling to meet the LVL and tie off each rafter with hurricane ties. BTDT. Had to add a 4x4 in each wall to carry the LVL. My span was 16' and required two 11 7/8" LVL's to hold up the center of 20' 2x6's. A pair of H2.5 ties were spec'd for each rafter.

1. 
   jdom | Dec 11, 2007 06:16am | #5

   Thanks, Ralph. I've got a 20' span (both ways). Any idea how I would determine the proper size of an LDL for my application?

4. 
   mike4244 | Dec 11, 2007 08:52pm | #6

   Put a strongback down the center of the span. 2x4 flat and 2x6 on edge that is nailed to the edge on the 2x4. Nail this to the top of the joists. This will stiffen the joists enough . You do not need to walk on top to insulate, staple the paper to the sides from underneath.Screw 1x2" rock , youre ready to tape.

   As another post mentioned you could also add braces from the ridge down, nail to the strongback every 4'-0.

   mike

5. 
   Hudson Valley Carpenter | Dec 11, 2007 09:13pm | #7

   The simple answer is you should forget storing anything on top because you need more than 6" of insulation in the ceiling to be effective. 

   Second, if you just put up the fiberglas batts, 10" or even 12" and then finish the ceiling with Tyvek, you won't have added any significant weight to the ceiling. 

   http://www.owenscorning.com/around/insulation/insulationhome.asp

   Sheetrock is not a good insulator, just a nice finish which provides some fire protection, so it's not a requirement.  I've seen numerous shops in upstate New York, insulated as I've described.  They all are very pleasant in the winter. 

   You can sheetrock the walls if you want to make the place a little neater looking.