Building a new shop

Ed in Tampa · Post by **Ed in Tampa** » Thu Jan 30, 2014 3:14 pm

JPG40504 wrote:He said 4' truss centers!

I am not sure I would even hang a ceiling with 4' centers and a 30' span!

I missed that. Now I know what the purlins are all about, thought he said 2 foot.

You are right and I agree.

hyRAMelu · Post by **hyRAMelu** » Fri Mar 21, 2014 4:32 pm

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.

hyRAMelu · Post by **hyRAMelu** » Fri Mar 21, 2014 4:32 pm

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.

JPG · Post by **JPG** » Fri Mar 21, 2014 8:15 pm

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.

Where ya obtaining 30' 2x4s?

hyRAMelu · Post by **hyRAMelu** » Sat Mar 22, 2014 9:33 am

Simply by overlapping two 16' 2x4's between the existing trusses.

JPG · Post by **JPG** » Sat Mar 22, 2014 10:36 am

hiramelu wrote:Simply by overlapping two 16' 2x4's between the existing trusses.

I think that will be simply inadequate.

The 2x4 will struggle supporting their own weight!

The overlap joint will have extreme torque stress.

Ed in Tampa · Post by **Ed in Tampa** » Sat Mar 22, 2014 6:59 pm

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.

You would be better off placing the 2x4 perpendicular to directions of the truss. Putting them 2 ft OC across the bottom of the trusses. Putting them parallel with a 30 foot span will make them next to useless.

However putting them across the bottom of the trusses would give a 4ft span and they would be able to support something.

My humble opinion.

teacherman · Post by **teacherman** » Sun Mar 23, 2014 12:12 am

hiramelu wrote:Simply by overlapping two 16' 2x4's between the existing trusses.

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 side

skou · Post by **skou** » Sun Mar 23, 2014 12:32 am

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.

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.

steve

hyRAMelu · Post by **hyRAMelu** » Thu Mar 27, 2014 12:09 pm

Would anyone here know how to acurately calculate the "ceiling load" for a 30x50 building with 2x4 roof trusses with 4' O.C. spacing?