When you get a new asphalt shingle roof, the daily difference is simple: no more bucket in the attic when it rains, and peace of mind for the next thirty years. The actual crew work usually takes just two to three days from stripping the old layers to nailing down the last ridge cap.
Late fall and early spring are the best times to book this work because roofing crews are slower and more willing to negotiate on price. Before you sign anything, get at least three different quotes from local contractors to make sure you are not overpaying for materials or labor.
That 0% intro window is a strict deadline, not free money, and any remaining balance left over when those 18 months are up will suddenly start racking up standard interest charges.