Before you get to work replacing your shingles you should determine what caused them to fall off in the first place.
Is it normal for shingles to just fall off roof.
It s normal for shingles to lose the colored ceramic granules as is happening to you and i.
On 2015 09 08 by mod some granule wash down is normal on new roofs but what you describe is not.
Where one shingle tab blew off your roof you have a 1 in 3 chance that the missing shingle was sitting directly above an open seam between the shingles below.
In other words when shingles are new excess granules from the manufacturing process fall off when somebody walks on roof and when it rains.
Have the gutters cleaned out and check their slope.
It seems to be most prevalent early and later in the shingles life.
These other granules are not attached to the shingle so they are likely to fall off slowly from manufacturing to the packaging to the installation on your roof and even after.
Later in life as the shingles become more brittle granules continue to fall off exposing the shingles fiber underlayment.
That s because this type of roof shingles standard 3 tab asphalt shingles are installed side by side with the next upper row of shingles covering the side seams.
How long will it continue to do so.
In many cases unusually strong wind is to blame but installation issues can make shingles more vulnerable to weather patterns or even cause them to fall off when wind is minimal.
New asphalt roof shingles.
Just had a new roof put on and it has been shedding granules.
If the asphalt is poor quality if there s too much powdered stone filler in the shingles or the manufacturing process is not great the granules will eventually come off the shingles much faster and in greater amounts than is normal.
While a bit of granule loss is normal there may be a need to inspect your roof to ensure that the actual intact granules are still in place.