Scissor Truss Insulation

[dsp1]

I'll try posting this here since I didn't have much luck on the general forum.
I have 5/12 over 2/12 scissor trusses on the new 40x60 shop that just got put up and had some questions regarding insulation. My setup is a little different than normal post frame buildings since I put a standing seam roof on to match the house which means I have 2' on center trusses and 5/8 osb underneath the metal and underlayment. The building also has vented eaves and ridge. I was planning on using r-21 faced batts since the building is only going to be moderately heated in winter and not cooled in the summer. I'm sure an r-30 or 38 would be much better but I can't afford to panel the roof and walls and the walls really need to be finished since I'm running exposed for the wiring and nobody around here has enough r-30/38 batts to get the job done and has no idea when any restock will be shipped. Is there any issues with possibly paneling the ceiling at a later date and blowing insulation over the batts that are already there? For anyone that has done scissor trusses, were there any issues you ran into or things you should have done/not done? Is is better to use faced insulation or unfaced with a separate moisture barrier? I'm planning on putting a forge in there so there will be a decent amount of hot air going up to the ceiling. Any info you all can provide will be appreciated.

 

[toyotadriver]

I would put the thickest batt insulation between the trusses I could get/afford. I would then cover the batts with rigid foam insulation. The thicker the better and tape all the seams. Then, I'd strap the roof with 2x4s and cover with the metal (if you are going with metal). Won't be cheap but will be well insulated and well sealed up. My main concern is warm moist air from inside the shop contacting the underside of the cold roof in the winter.

 

[dsp1]

Well, I just got of the phone with a place that has almost enough r-30 batts to do the whole ceiling for basically the same money the box stores want for the same amount of r-19 currently so I'm going to use that. Your other suggestions are good, they'll just have to wait a year or so since the walls need to be insulated and I need to run the wiring. This building is already ridiculously more expensive than it would have been a couple years ago. The only thing remotely cheap is lumber for internal framing. The Amish mill down the road charges 2.50 for 8' 2x4's and $3 for 2x6's. Downside is you need to sticker them and let dry for a couple months. I was going to go with metal panel for the roof but at the current price it is the same amount to use Dutch lap or shiplap siding from the Amish and it looks a lot nicer.

 

[Eplebnista]

Sounds like your problem is solved. I made the mistake of not having my scissor truss garage ceiling insulated when it was being built and ended up doing blown in cellulose after the ceiling was up and I can tell you that there are few things in life you want to avoid more than having to do the prep work of sealing openings, installing baffles and blowing insulation while working in the limited space available in a forest of scissor trusses.