The result extends the Shots' unbeaten run in the Conference to four games but Halifax will be aggrieved at having to return north with nothing to show for their efforts and they have now only won one of their first six games.
Halifax started brightly putting together a string a passes that highlighted why they were so close to achieving League football last season but they failed to create anything substantial with their early pressure.
The closest they came to opening the scoring came in the sixth minute when Shots keeper Nikki Bull appeared to pick the ball up outside his penalty box.
However, the referee played on after consulting with his assistant who was directly in line with the incident, but the call was dubious at best.
Aldershot created the first real chance on nine minutes. Halifax cleared a free-kick poorly and the ball fell to the feet of in-form striker John Grant. The former Shayman decided to shoot from the edge of the area but he lacked composure when it mattered and Craig Mawson made a simple save.
Grant went some way to making amends when he tackled Mark Roberts and played the ball in to Ryan Williams. He in turn found debutant Ben Harding on the edge of the area, and he hit his shot cleanly towards the right-hand corner but it flew just inches wide.
Halifax responded four minutes later when Andy Campbell sent Danny Forrest down the right-hand side. He picked the ball up 35 yards from goal and went on a mazy dribble that took him into the box. He cut inside Phil Anderson but his shot lacked venom.
In the 25th minute Williams should have done better when the Shaymen defence cleared a Barnard free-kick straight to Ricky Newman. The former Brentford man found Williams on the edge of the box but the ex-Bristol Rovers player's effort was way off target.
Halifax lacked consistency in the first half. It was exemplified in the 27th minute when Gus Uhlenbeek nut-megged Williams and delivered a beautiful cross from the by line. Frustratingly for Chris Wilder not one Shaymen was in the six-yard box.
However, the best chance of the first period did fall to Halifax on the half-hour mark. Lewis Killeen slipped Barnard on the halfway line, although he appeared to impede him. The referee waved play on allowing the winger to find Forrest. He neatly played in Martin Foster who fired in a shot from inside of the box.
Bull reacted brilliantly to deny Foster but could only parry the ball to Ryan Sugden. The former Morecambe striker, who was given permission to talk to York City this week, horribly blazed over from three yards with the goal at his mercy.
The second half proved to be a tense affair as neither side created any significant opportunities.
Killeen was put through by Sugden inside the area. He held off Anderson's challenge and shot from the angle but Bull reacted well to make the save.
Ryan Scott then nearly sliced into the own net but the game hinged on a key referee decision with eight minutes left. Scott appeared to handle the ball in the box but amazingly play was waved on.
With stoppage-time approaching Barnard grabbed all three points for Aldershot. Ricky Newman squared the ball to Barnard from a free-kick on the edge of the area. Unmarked he drove the ball into the bottom right-hand corner of the net to send the Recreation Ground faithful into delirium.