actually the EBE has a stairs prefab which is angled, can you not look at how the stairs have been done in the EBE and base your A frame roof using the same method. Not sure about the pre-bake issue, sounds like a bug to me.
Professional Programmer: Languages- SAS (Statistical Analysis Software) , C++, SQL, PL-SQL, JavaScript, HTML, Darkbasic Pro (still love this language), Purebasic, others
Hardware: Dell Precision 490; AMD Radeon HD 7570; 12GB.
FPSC to GameGuru Tools: SegAutoWelder, Entity+Weapon Welder, FPEtoBAT