The downside is that.
Replacing entire roof.
Torn or damaged shingles can be removed and new ones can be slipped in place.
So can you replace just part of your roof or is at an all or nothing deal.
Well it depends on the level and expanse of the damage.
Make minor repairs on the roof if it is in good condition.
There are missing shingles missing shingles will need to be replaced right away.
If not replace bad wood with new plywood sheathing or 1 x 6 sheathing boards whichever is applicable to your type of roof.
The shingles are missing pieces if a piece of a shingle is missing then the entire shingle will need to be replaced.
Whether your home had an encounter with a windstorm a bit of hail or a fallen tree it s difficult to justify an entire roof replacement if just part of your roof has been damaged.
Replacing shingles due to wind damage or a fallen limb is a relatively easy and inexpensive.