Roof Pitch?

[karoc]

Guys if you were building a shop say 32’x70’x12’ and no worries about snow load, not using attic for storage what Pitch would you want? I was planning on 4/12 pitch but maybe 5/12 give little more space to allow heat get out through Ridge vent. These would be Trusses, I don’t want beam or columns this go round. I don’t know if there be big cost difference or not between 4/12 or 5/12

 

[kwb]

5/12 is about all you can walk comfortably, it also is a point where it starts to look "right" to me. I would love to have 8/12 to give a better look but I am a practical man that lives in among the trees and walking to clean the roof periodically is important.

 

[Sumboodie]

5/12 is about all you can walk comfortably, it also is a point where it starts to look "right" to me. I would love to have 8/12 to give a better look but I am a practical man that lives in among the trees and walking to clean the roof periodically is important.

6/12 is fine to walk on. That's what my house, garage, and shed are.

Or, I should say, fine to walk on when it's not plywood and icy.
Broke my back in 2010 from that fall. Deal with it everyday.

 

[kwb]

I think I forgot to mention I really don't like heights

 

[FMB4]

Yep, 5/12 or 6/12 is what I'd do.

 

[K'ledgeBldr]

Nothing less than 5/12
Remember, 3/12 is the least for most shingle manufacturers- but with the current climate- i wouldn't put shingles on a 3/12 unless there is membrane AND roll roofing underneath. With wind and driving rain, it would certainly be easy for water to backtrack.

 

[karoc]

6/12 is fine to walk on. That's what my house, garage, and shed are.

Or, I should say, fine to walk on when it's not plywood and icy.
Broke my back in 2010 from that fall. Deal with it everyday.

Dang, that's what I don't want to happen to me. But glad you able to get around now, I'm like ya'll I just don't have nerves anymore for heights.

 

[u2slow]

I chose my roof pitch based on how my bylaws measure max roof height (i.e. 'mean' roof height; halfway up). By bringing the eave closer to the ground I could have a higher ceiling inside. That sweet spot for me was 6/12 pitch. Its still tough to walk on because its metal. Snow slides off real quick.

 

[mike93lx]

Staying off a roof, regardless of pitch, is a good idea.

My last house was a 5 or 6 pitch. OK to walk on if I had to.

 

[FMB4]

Nothing less than 5/12
With wind and driving rain, it would certainly be easy for water to backtrack.

Yep, that and having high winds blow the shingles off.

 

[FMB4]

Staying off a roof, regardless of pitch, is a good idea.

As a former roofer, in an earlier life, the saying was "it's not if you fall off the roof, but when" (this statement is true). The other saying was "you'll only fall off this roof once".

 

[jack stand]

If there's no snow considerations, it's mostly aesthetics beyond the type of roof. (materials)
3/12 is fine for a metal roof.
In my "eye", a minimum 5/12 with good overhangs at both the eaves and gable ends is a must.

 

[nadogail]

My home built in ‘88 has a roof of light weight concrete tiles, very pretty to look at but there is no way I will climb on it.
The house a attic is a crawl space for a small person. My shop roof allows a grown man to crawl under it.
They are both tight.
Good Luck in finding your best options.

 

[rayra]

4/12 is pretty comfortable to work on. Works ok for solar, too. About all I saw in SoCal, excepting houses pretending they were somewhere else.

 

[Kaizen]

what is the house or neighbor houses pitch? That would look the best.
For cheap storage to an 8/12 and attic trusses. cheapest storage sq ft price you'll find.

 

[K'ledgeBldr]

As a former roofer, in an earlier life, the saying was "it's not if you fall off the roof, but when" (this statement is true). The other saying was "you'll only fall off this roof once".

You forgot one-
“It’s not the fall that hurts; it’s the THUD at the end of the fall!”

 

[racecougar]

Let's take a step back...what roofing material are you planning to use?

 

[tstaude]

The barn I am reconstructing is a 7/12, it is really steep to walk but I put up all 60 sheets of 5/8 osb myself. And I don't really car for heights. Used a harness too

My other garage is a post frame building with 3/12 pitch. Talk about easy to walk!

 

[jar944]

9/12 to 12/12 looks best imho. Not fun to work on though.

 

[yeldogt]

Back in my 20's when doing one of my first bungalows -- got about 1/2 into the front tear off and said "I'm never doing a tear off again" . About 1/2 into the new shingles ... said the same thing about new. Roof/Drywall/Insulation ... not worth doing it yourself. The savings are small and the first two can be dangerous and backbreaking ........ Plus, when building new --- steep pitch is the best looking.

 

[justler]

Both pole building places I had quote me spec 4/12 pitch for their corrugated metal roofs (Pioneer and Shirk). I'd like to do a 7/12 or 8/12 but it added about $4k to the cost...

 

[rburke65]

I have a 32’x56’ 13’ side wall with an attic truss whic( is a 8/12 pitch., with a 12” overhang.

 

[matt_i]

Easy way not to fall off the roof, park cars or trucks on either side of the roof. Run appropriate rope all the way across the roof peak and secure to both vehicles. Tie something like a "butterfly loop" in the center of the rope at the peak and attach your fall harness and lanyard.

When i was working with plywood sheathing I welded up a "U" shaped bracket which simply slid over the edge of the top sheet of plywood in the gap where the ridge vent was to go. Was around 8" long so it would have to tear out a respectable chunk if stressed.

I bought the fall harness and lanyard on ebay. Very suitable for occasional use. You want to have a spotter to rescue you if you do fall and are hanging from the harness/lanyard.

A 4:12 or 5:12 would be what I would use with synthetic underlayment...fantastic stuff that is.

 

[finn]

My house is shingles and 12/12.

I don’t go up there anymore.

My garage and shop are both steel and 5/12. They shed snow fine, but I don’t go up there either. With no snow load, 4/12 is good. Any steeper is for aesthetics, and will cost more money.

 

[manwithtools]

Easy way not to fall off the roof, park cars or trucks on either side of the roof. Run appropriate rope all the way across the roof peak and secure to both vehicles. Tie something like a "butterfly loop" in the center of the rope at the peak and attach your fall harness and lanyard.

When i was working with plywood sheathing I welded up a "U" shaped bracket which simply slid over the edge of the top sheet of plywood in the gap where the ridge vent was to go. Was around 8" long so it would have to tear out a respectable chunk if stressed.

I bought the fall harness and lanyard on ebay. Very suitable for occasional use. You want to have a spotter to rescue you if you do fall and are hanging from the harness/lanyard.

A 4:12 or 5:12 would be what I would use with synthetic underlayment...fantastic stuff that is.

Never attach safety ropes to a vehicle. Haven't you heard the old tale of the farmers wife who drove away with the car while her husband was tied to it while working on the barn roof?

 

[karoc]

Let's take a step back...what roofing material are you planning to use?

5/8 decking on trusses 16"OC and the synthetic underlayment with 29ga metal

 

[NUTTSGT]

5/8 decking on trusses 16"OC and the synthetic underlayment with 29ga metal

Metal will definitely change the the pitch which you can walk on.

I doubt you have a Menard's local to you but you can use their truss builder app. Put in the same information and just change the pitch from 5/12 to 6/12 if you want a gander at priced differences.

 

[manwithtools]

5/8 decking on trusses 16"OC and the synthetic underlayment with 29ga metal

That seems like overkill for an area with no snow load. How about trusses 48" on center with 2x purlins and metal on top of the purlins? Much cheaper and if properly deigned, should be fine for you areas wind loads.

 

[u2slow]

5/8 decking on trusses 16"OC and the synthetic underlayment with 29ga metal

Sounds serious. My roof is about 40x50' footprint. 24" spaced trusses and I upgraded to 1/2" ply on roof for the metal. Its built with whatever the local code snow-load consideration is here.

 

[mike93lx]

My last house in MA had trusses 24oc with 1/2 sheathing. It had 3' of snow on it many times.
16oc trusses and 5/8 is just a waste of money but it is yours to spend.

 

[karoc]

Thanks u2slow and Mike, that will cut cost way down thank goodness.

 

[mike93lx]

I would also price out 8' OC with 2x4 purlins. With 4' OC, I imagine you would need purlins too, and without a snow load, moving them out to 8' might work

 

[u2slow]

My brother had problems with a large metal roof using 2x4" purlins. Bad galvanizing and ongoing screw leaks. By 10 years he had it all re-done. Plywood and asphalt shingles.

I think I'd still go with plywood roof sheathing from the start.

 

[mike93lx]

My brother had problems with a large metal roof using 2x4" purlins. Bad galvanizing and ongoing screw leaks. By 10 years he had it all re-done. Plywood and asphalt shingles.

I think I'd still go with plywood roof sheathing from the start.

Using purlins doesn't stop you from sheathing. But you can't just sheath over 4-8' OC trusses

 

[Copymutt]

I have fallen several times in my younger days. 5/12 pitch & 12 feet to the ground. That’s a little misleading as it was only a drop of 12 inches to the snow pile!

 

[manwithtools]

My brother had problems with a large metal roof using 2x4" purlins. Bad galvanizing and ongoing screw leaks. By 10 years he had it all re-done. Plywood and asphalt shingles.

I think I'd still go with plywood roof sheathing from the start.

Literally thousands upon thousands of these buildings built with large pitch trusses and 2x purlins that don't have leak problems. Metal roofs with screws "can" have issues regardless of substructure.

 

[u2slow]

@mike93lx his trusses were 24" spaced anyway.

@manwithtools I have no doubt there are, but bro chickened out on steel over that experience... and it cost him large to switch over since he 'saved money' not sheathing it in the first place. (I have the odd screw leak too.)

 

[manwithtools]

I have fallen several times in my younger days. 5/12 pitch & 12 feet to the ground. That’s a little misleading as it was only a drop of 12 inches to the snow pile!

Me too, usually on a sled or toboggan

 

[racecougar]

5/8 decking on trusses 16"OC and the synthetic underlayment with 29ga metal

As others have said, that is massively overkill. If you're going with metal, you don't need decking.

Metal will definitely change the the pitch which you can walk on.

Bingo!

That seems like overkill for an area with no snow load. How about trusses 48" on center with 2x purlins and metal on top of the purlins? Much cheaper and if properly deigned, should be fine for you areas wind loads.

I would also price out 8' OC with 2x4 purlins. With 4' OC, I imagine you would need purlins too, and without a snow load, moving them out to 8' might work

Agreed with both. You could significantly reduce your cost by going to 8' OC, either running 2x4 purlins on top or hung in between as shown below (stronger but more labor), and screwing the metal directly to the purlins.

 

[NUTTSGT]

As others have said, that is massively overkill. If you're going with metal, you don't need decking.

Since the OP is in Texas, he probably won't have any ice/snow issues.

However, if the building was in an area that gets snow and ice, I'd recommend decking under the metal for a lower porch or lean to roof. If snow or ice slides and falls off the upper roof, it can dent the lower roof surface. Using decking under the metal should prevent it.