Transact SQL :: Truncate And Insert Operation - Avoid No Rows In Table During Processing

I have a job which executes hourly.

Essentially:

Begin
Truncate table A
Insert into A
(Col1,
Col2,
Col3...
)
Select Value1,
Value2,
Value3...
From Table B
End

The insert operation query takes approximately 3.5 minutes to execute. What's occurring is the Table is immediately truncated, and there are no rows in the table for those 3.5 minutes.

How can I avoid having this gap - where there are no rows in the table for that period of time during the job execution ? The table could be locked, but that doesn't seem like the best solution.