Barrington, who played for Beavers` boss Gary McCann at Hendon, joins until the end of the season.
Barrington played against the Beavers in last year's play-off final and will add some much-needed firepower to the strike force.
The 23-year-old becomes the second Guyana international in the Beavers squad along with Sam Cox.
So far this season he has made 10 appearances for Braintree scoring one goal in a 2-2 draw with Sutton United back in November.
The former Leicester City trainee has had spells at Nuneaton Borough, Bishop`s Stortford and Margate.
He certainly endeared himself to his new supporters on Saturday as he came off the bench to make his Beavers` debut and scored a 94th minute equaliser against Slough Town.