Yes, it’s possible to replace drip edge flashing without removing shingles, but it’s not a good idea. You’ll have to lift the bottom shingles up to remove the old drip edge, install the new material, and then lay the lifted roofing material over the new drip edge. Bending roof shingles can cause damage, and if you have ongoing issues with roof leaks that prompt drip edge replacement, it’s a good idea to consider a roof and drip edge replacement to avoid ongoing issues.

Rain shouldn’t come in through your ridge vents unless your vents are damaged or the rain is accompanied by very high winds. Most ridge vents use flashing or baffling to keep out rain, snow, and debris. If your ridge vent isn’t baffled, rain is more likely to enter your attic, so ridge vents with baffles are a better choice in areas with regular rainfall.

The roof overhang, also known as the eaves, does count as part of the roof’s square footage because it must be covered with the roofing material. The overhang is one of the reasons why you can’t base your roof's square footage on the square footage of the house. The roof square footage must also account for the pitch of the roof as well as the eaves.

If you choose to get a personal loan to finance a roof, you will want to aim for a “good” or “excellent” credit score for the best rates. That means a credit score of 690 or more. If you aren’t sure of your credit score, you can request one free credit report per year from each of the three major credit bureaus: Equifax, Experian, and TransUnion. Many banks also provide free credit reports monthly.