My roof is 13 years old with 25 year asphalt shingles. The shingles are curling and cupping on the eaves on the north side of the roof. Do I need to replace the roof? What caused just this area to curl? Too much heat in the roof internally? The eaves are vented but the roof peak is not. This is a cathederal type ceiling so there is very little attice space and of course an attic fan is not an option. The curl is present both on the north eave of the home and the north edge of the attached garage. There is not a lot of pitch to the roof, I would guess it is about a 12/3. this is a manufactured home built in 1971.

Heat Is A Big Factor There, It Does Make A Difference To Have Your Ridge Vents Installed, Every Roof We Do We Add Them In.
Its Nothing More Than Cutting A 2" Rip Of Both Sides Of The Ridge And Installing The Ridge Vent.
Id Advise To Have That Done As For The Shingles Right Now Id Plan To Reroof With Some 25 Yr Shingles, The Architecual Shingles Hold Up Much Better But Cost A Little More.
As For The Slope It Shouldnt Be Less Than A 4/12 For Code, At Least Its Code Here In Nc.

You Said Your Eaves Were Vented, Are Then Vynial Sofet Or 3/8 Wood With A 2" Vent Strip In Them?

They are 3/8 wood with 2 inch vent strip. I guess the problem is that there is no peak vent and the shingles are a dark brown so they will draw and hold more heat. The building code most likely did not exist here in 1971 and I'm sure there was no inspection done. Am planning on having vinyl siding, new fascia and soffett installed this year but really did not want to tackle the roof issue for a couple more years. If push comes to shove I may jhust have to do the roof myself and enlist help from the relatives.

Cathederal ceilings frequently have no attic at all so they get much hotter. Have someone check your pitch and compare to the shingle manufacturers spec. Maybe your roof is too flat for this shingle, if not there may be some warranty money coming to you. Curled shingles is like death and taxes. Its coming and signals the end.