Pergola roof diy planning

[Max T.]

Planning to put a toja grid pergola on my deck when the weather gets warmer. It will measure about 10 feet long (from the back of the house) by about 12 feet wide (width of the deck).

I want to put a corrugated metal roof on it. I plan on using joist hangers with 2x4s every 16 inch on center.

The water will run off the side (the 12 foot width). What should my minimum pitch be? How much higher should the high side be compared to the low side, considering a 12 ft run?

We do get some snow in Philly. Not a ton but more than a little bit. Heat cable to melt it after bigger storms?

[Mike Reynolds]

Originally posted by @Max T.:

Planning to put a toja grid pergola on my deck when the weather gets warmer. It will measure about 10 feet long (from the back of the house) by about 12 feet wide (width of the deck).

I want to put a corrugated metal roof on it. I plan on using joist hangers with 2x4s every 16 inch on center.

The water will run off the side (the 12 foot width). What should my minimum pitch be? How much higher should the high side be compared to the low side, considering a 12 ft run?

We do get some snow in Philly. Not a ton but more than a little bit. Heat cable to melt it after bigger storms?

The one you have in the picture will not hold up to the snow load of Texas, let alone Pa. For rain, you need 2/12 pitch for metal. Shingles you need 3/12 pitch. This is minimum. Problem with most of these are they are afterthoughts and you end up going to the eave or soffit and dropping it from there. 

So, 10 feet long, you need to drop 20 inches for a 2/12. 2x4's will not hold it either.