My roof over the deck project is coming along, slow but moving. Rafter length from ledger board to beam is 7' ,with a 12" overhang. From the bottom of the rafters to the deck on the house side is 7' and from the deck to the top of the beam is 6' 3 1/2"" which gives me just under a 1:12 pitch. I can't go any higher on the house side, If I drop the beam by 1 1/2", putting the top of the beam at 6'2" it changes pitch to just over 1:12, gaining only slightly more slope. I would hate to take down the beams and Simpson bracket to remove 1 1/2" from all the post to gain 1/4" or so of pitch. I plan to run 2x4 purlins 24" OC on top of rafters and install exposed fastener metal roofing, exposed framing underneath. So really I'm asking if a 1:12 pitch with metal roofing will work ? Yes it's not ideal , but it's what I got to work with. I realize I will have to remove any heavy snow we may get. Any opinions or advice ? I hate building projects. -Thanks

Here's an idea of what I'm building.

Thats pretty flat but that shouldnt be a problem if you build it strong enough.Wet snow gets pretty heavy,but its heavy on a sloped roof too.
Shovelling a roof is not a big job since the work is all downhill.I use a snow float on mine at least once a winter-makes for an easy job.

I would put plywood decking on and install a rubber roof. Whatever you do you need to make sure that your tie in to the shingle roof is done correctly and permanently. I have seen many cob jobs that will last a few months or so and then they start leaking. They last just long enough for the contractor to get paid.

Ya, now that you say that I'll go 16"OC on the purlings that sit on the 2x6 rafters. All my posts are 6' OC also. Getting water to run off fast enough in a heavy down pour is my main concern.

The plan is to get the house and porch roofed all at once so it gets the proper flashing and sealant done right.

You will be just fine with that pitch.

Don't know how far along on the project you are.
But if your post are not installed yet, you could go a foot taller on the back posts and eliminate that roof tie in that will pleag you for years to come

I was taught that 3/12 was the min for shingles and 1/12 was min for metal roof. Just make sure you buy metal with high ribs and not the corrugated almost flat ribs.

I would over build the rafters, cover it with plywood instead of OSB and use a rubber roof you will be fine. On that small of a roof it will not cost you that much more and cheaper than having it come down or leak.

going to be roofing the house anyway i would run the rafters up on the house and get more pitch and do way with the posts and beam at the house.
i would want at least 6 foot 8 for head room under the beam at the outside.

Would nesting the purloins help?

I was wondering where you were going to put the signs that said "Low Ceiling" or you might want to "Duck" if you stick to your original plan.

Since you are re-roofing the house at the same time, I like Cotton's idea much better and it fixes the low ceiling issue as well.

My Wife would have a dormer coming out of the roof extending over the deck probably both sides of the house

I put a metal roof on my camper that gets left at deer camp all year every year and it's 20' and I only have about a foot difference in 20 feet . It's been on for 4 years and no problem,,,,, I did caulk all the seems just in case sitting snow that started to melt and couldn't escape off the back didn't seep into the seems .

1970 camper and no more leaks since I did this, good luck

Water will run off that pitch if you don't get any debris on the roof. I would be more concerned with building codes. Here in Michigan you would be taking that structure down as soon as some nosey neighbors report you to inspector.

Since it is a porch roof a little leakage would not be critical as long as none of it can get into your main structure wall, IMO. I have done similar except that they farthest out lowest stringer rafter was placed above the roof surface and the roof metal extended underneath and was washer screwed from below up into it(every rib of the pole barn type metal). Your pitch is too low for any snow to slide off the lower end anyway and my roof was only 14' wide so roof raking from the sides was not a problem. This let my oversize my stringer for extra strength and gave my several more inches to increase my pitch to about 3/12 instead of a flat roof I would have had to have if stringer was underneath metal. I saved more height by making my rafters out of two 2x4s nailed to the sides of a 2x3 and turned my purlins flat and halved the spacing. It is over an open season treated porch deck so 100% water proofing is not critical and it has held snow up to 3' thru blizzards until I could clear it. If worried some well placed 2" angle iron can double it's load capacity. "U" rafters also were secured up into above metal stringer and 45ed on lower corner for head clearance.

I don't know how deep/thick your floor slab is or if it is at or above grade but I have done sunken inner step to gain a couple of needed inches under outer stringer.