On the backside of my house the shinglers appeared to use a upside down shingle under the starter shingle to act as the overhang into the gutter.

On another portion it appears the felt paper extends a bit longer than the starter shingle to act as the overhang. Overtime some of this appears to be curling upward and I have put a slit or two in the overhung felt paper to flap it into the direction of the gutter.

Then along the sides of the house there is no extra shingle and the felt/icewater layer is not extended as the overhang. The starter shingles are about 1/2" to 3/4" overhung in this case.

In fact on all 4 sides, regardless if the extra shingle is used or the ice/water layer overhangs the first shingle along the gutters over hangs that same amount.

I know pictures would help, but can anyone venture to say whats going on here? Can someone explain what the proper overhang is?

 

Installing an upside down shingle under the first course has been a standard practice for a long time. That takes the place of how the shingles overlap, otherwise there would be a gap between tabs. It's not needed on the sides.

 

The roofing paper and Ice and Water shield never should have been extending out beyond the roof line.
Only the starters and shingles over hang.
Your seeing why it's not done that way.
Did they install a metal drip cap on all sides as it should be?

 

How much should the first row of shingles stick out as an overhang?

Should I trim the felt paper back completely... if I do that there would 1/2" to 3/4" of overhang of the first row of shingles?
Someone mentioned below about the first upside down shingle? Why wouldn't that be done on the sides?

Im not sure what that would look like but there is no exposed metal.... if you lift the shingle a bit at the overhang there is not something that counter flashes over the seam of the aluminum facia..... in fact you can see the seam.

Is that a major defienciency? Can it be added without having to pull shingles?

 

Each shingle manufacturer has their own preferred starter course overhang--most I've been around is either 1/2" or 3/4". I think I've only seen starter courses (with an overhang) used on rake edges once in the last 40 years, meaning it's not done very often. If your roof is missing its drip edge (L-shaped metal flashing, with a small kick-out at the bottom of the overhanging leg), the sheathing edges will be visible. If that's the case, they will eventually turn black and rot over time, leaving you with a very expensive repair bill.

 

I was also reading in a roofing book that a drip edge is not required in all regions and are not always installed. It was also referring to a drip edge as COSMETIC "Roofing The Right Way" by Steven Bolt which is contrary to what I have been reading elsewhere??!

Anyway, there is no drip edge on my roof... should I consider this a major deficiency?

And should I trim back that felt that extends past the shingles? Or is there a valid reason why that would be done like that?

Im asking if I should trim because about half of it has already torn off and most of it is curling. I am assuming water hits its and travels laterally along the curled portion. Without it the shingles overhang by 1/2" to 3/4" maybe even an inch and they are not curled....

should I lap it off?

p.s.- This is a one story hip roof roof with no gables or anything like that... if that makes a difference?