Australia could only manage to get the wicket of Root, thanks to Peter Siddle who helped his side get the only breakthrough in the afternoon session. Before Siddle packed back Root, the English duo of Root and Rory Burns had added 132 runs for the second wicket.
Root's fall saw Joe Denly joining opener Burns (82 batting off 176 balls) and the duo ensured that the visiting bowlers could make no further inroads.
Earlier, it was a solid show from the English batsmen in overcast conditions. Starting the day on 10/0, the Englishmen went into lunch at 71/1 with skipper Root (11) and Burns (41) at the crease.
Before that, James Pattinson removed Jason Roy (10) in the eighth over, caught by Steve Smith in the slip cordon, but that was the end of the joy for the Austral as both Root and Burns ensured that they didn't play any false shot. They followed the golden rule of giving the first session to the bowlers as both of them looked to produce a tight defensive game.
For Australia, it was all about bowling their hearts out as they managed to score just 284 in their first innings, thanks to a brilliant hundred from Smith. The former Australia skipper's 144 ensured that the Aussies weren't bowled out under 200 in the first innings of the first Test of the high-voltage Ashes series.
Poor umpiring was once again on display on Friday as Joel Wilson gave Root out caught behind off Pattinson, only for the DRS to come to the English skipper's rescue.
England still trail by 213 runs and the Aussies know that they must pick quick wickets to unsettle the English batting if they are to make a match out of this Test.
Brief scores: England 170/2 at tea (Rory Burns 82*, Peter Siddle 1/31) vs Australia 284 (Steven Smith 144, Broad 5/86).
( With inputs from IANS )