Quoting Tommy, the oldest Henderson boy, "here's the thing about that". We're not dealing with a porch.
By the way, when shingles are applied on a pitch below 2" the warranty is void. If shingles are applied over roll roofing, two warranties are void.
I never pay any attention to warranties, getting a manufacturer of construction products to honor a warranty costs more than just paying to fix it yourself. An example, most caulking has a warranty of 50 years written on each tube, read the mall print, you have to provide a copy of the receipt for each tube, you also have to provide the actual computer code cut from each tube, if you succeed they limit their liability to the cost of each tub and specifically reject any consequential damages, so you get $4.95 from the manufacturer and can have millions of dollars in mold damages..
Another example, I was doing ADA work on a large Catholic church, other things came up like leaks in copper flashings, looking at them it became obvious that large areas of the clay tile were deteriorating badly, the roof was within the 20 year warranty, I contacted the original contractors and they had no documentation of the purchase of the tile 20 years earlier, each tile had the name of the manufacturer stamped into the tile, the manufacturer declined to honor the warranty based on the lack of documentation, unbelievably the architect for the archdiocese wanted to reroof the church with the same tile even though they had just declined the warranty so they paid all over again (the architect determined that the failure was due to some bad clay from a bad pit) .
Another example, I never put caulking behind window fins even though flashing and window manufacturers all require it, the reason is my experience has shown that caulking lasts an average of 7 years on the weather side in this area (longer on other elevations), I water test all windows before any siding or stucco goes on (but after the lath), caulking will temporarily seal the window, if there are any leaks I want to know now, not 9 years later, plus good contractors never use caulking (I started in this business before caulking was invented), so none of my buildings have warrantied windows.