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I missed that. Now I know what the purlins are all about, thought he said 2 foot.JPG40504 wrote:He said 4' truss centers!
I am not sure I would even hang a ceiling with 4' centers and a 30' span!
Where ya obtaining 30' 2x4s?hiramelu wrote:The progress on the new 30x50 shop is going well. The 2x6 walls are complete with Certainteed 6" R-19 faced insulation batting and lined with
5/8" OSB sheeting.
I will be installing a metal panel ceiling with 5/8" ribbing. There will be
50-8'Lx3'W and 10-10'Lx3'W panels. The trusses were placed with 4'-O.C. spacing. However I figure to add extra 2x4 supports effectively making
2'-O.C. spacing for the ceiling. I plan to cut out the lighting outlets with a Rotozip tool after plenty of measuring/remeasuring before any cutting.
Currently I am debating whether to use a double layering (minimum) of the 6" R-19 batting or blown insulation above the ceiling.
I bought a Dewalt 7730 radial arm saw for the shop to provide project assistance.
I think that will be simply inadequate.hiramelu wrote:Simply by overlapping two 16' 2x4's between the existing trusses.
hiramelu wrote: The trusses were placed with 4'-O.C. spacing. However I figure to add extra 2x4 supports effectively making
2'-O.C. spacing for the ceiling. I plan to cut out the lighting outlets with a Rotozip tool after plenty of measuring/remeasuring before any cutting.
It seems to me you are describing 2 x4s at 90˚ to the trusses, those 2 x 4s being called the purlins, a term I've also heard used to describe the joist to rafter diagonals braces, which of course are part of the truss. If this were my building, since you have a such a long span, AND 4' centers rather than 2' centers, I would keep the weight up there to an absolute minimum, and insulate like crazy right over the ceiling. Gable and ridge vents can move hot air out of the attic space. Placing insulation directly under the roof causes huge heat buildup on the roof, and the recommended inch and a half air space between insulation and sheathing is simply not enough to avoid thermal stress on the materials, IMO. It's a big building, and if you wanted a usable attic, you'd have framed it differently. Snow loads on a 5/12 can be significant, and it is shallow enough for the snow to stay a while and not avalanche until it melts. Remember, this is a long span. You have enough space to build all the storage shelves you'd need, or you can slap a lean-to on the sidehiramelu wrote:Simply by overlapping two 16' 2x4's between the existing trusses.
Nor strong enough to walk on. If you had 2X6s at 2 foot spacing, OSB or plywood would work, though. Unless you weigh less than 60 pounds, do NOT walk on sheetrock. If you're lucky, you won't catch a 2 by between the legs, when you fall through.benush26 wrote:Don't know if this idea is too mediocre for your wants, a friend suggested to me that I just lay sheets of sheetrock on top of the 2bys and lay insulation on top of those as I work my way across the ceiling. It allows me to keep my fluorescent lights tucked between the bays and if I do decide to make a more permanent ceiling solution, I have most the material on hand.
This is neither elegant nor permanent, but allows me to semi enclose the space.