Help with trusses

[aort11]

I recently bought a house with a pole barn in place. It was a midwest kit, 30x45x10. The trusses are on 9' centers, but they look fairly large. They are 2x8 top chord, 2x6 bottom chord. I'm trying to figure out how I should finish the ceiling. I have found a couple different things. It was built in 2003, so no one has the original records. On the Midwest site, I found this:

and this...

30′ Span
35# @ 9′ OC 4/12 Pitch 7-7/8″ Heel Height
40# 30-5-5/35-4-1 @ 9′ OC 4/12 Pitch 7-7/8″ Heel Height

I have tried to contact midwest, but they aren't the quickest to reply. How would I determine if my dead load is 1 or 5? It would make a big difference in what type and how much insulation I can use. I plan to run 2x4's between the trusses on 4ft centers and use metal liner panels.

Thanks

 

[tomroblee]

Your chart shows 1# per square foot dead load with the trusses 9' on center. I imagine that the weight of the metal you are planning to use is about that amount----not including the weight of the 2 x 4's, fasteners etc.

 

[aort11]

It does show that in the chart, but the listings showed two different load ratings for 30' span, 9' center truss. It shows a 30-5-5 and a 35-4-1. Also the same truss on 8' centers is a 5# rating. Just seems like a lot when over this span it would only be 1 extra truss. I was just curious if anyone has dealt with the Midwest kits from Menards or directly from Midwest.

 

[tomroblee]

I went to the Midwest web site. You are right, it is confusing.

From what I could see, one of their pages showed that them made two different post frame trusses for a 30' span with a 4/12 pitch. Sku 187-7452 was a 35# total load truss, and Sku 187-6806 was a 40# total load truss with ratings of 30-5-5 or 35-4-1.

However, there is also a page that lists both the 35# and 40# trusses with a 30' span and 4/12 pitch as Sku 187-7452

It appears that the ratings on their website were as of April 2007. If your barn was build in 2003, the truss design may or may not have been the same as that shown in Midwest's current literature.

 

[aort11]

I got a call back from Midwest. They said that truss is capable of a 20-4-5 on 9' centers. Due to my location the #20 rating is sufficient. It looks like I'll be able to continue as planned.

Sent from my DROID RAZR using Tapatalk

 

[never enuf time]

Well if the roof load is ok, lets work on the ceiling. I would put 2x6 perpendicular to the trusses on 16" centers. Start your first one off the wall at 15 1/4", Then 16" off this one. Then insulate or drywall/blown insulation.

 

[aort11]

I was planning on using 2x4's on 4' centers and using metal liner panels then blow in R49 to R60 cellulose. I couldn't decide on 2' or 4' centers, but everyone says the metal should be fine at 4'.