Feared front rows from Argentina, France and Georgia were seen off during the World Cup while Les Bleus' collapsed scrum yielded a penalty try to Ireland four weeks ago.
The breakthrough in Paris was fitting recognition for one of the most improved departments in Ireland's game, but Horan insists there is still more to come.
"It's about building on what we've achieved so far," said the Munster loosehead.
"We can't go shouting from the rooftops about what we've done in the scrum so far because it only takes one or two bad scrums in a game to bring you back down to earth - literally.
"We don't want to get complacent. We have to keep improving. We want to use the scrum as an attacking option for the team.
"It's a great way for us to attack and it's also a great way of disrupting another team's play and their momentum.
"It's a key area and we've seen how it can affect the game so it's something that we'll keep working on.
"If you sit back on things that's when things start going badly."
Ireland may never match the scrummaging prowess of sides like Argentina but the continued criticism of their front row is ill-informed.
The return of Paul O'Connell from a back injury for his first Ireland start since the World Cup will further bolster the set-piece.
O'Connell's presence provides Ireland with a timely lift heading into the business end of the RBS 6 Nations - and lightens the burden on skipper Brian O'Driscoll.
"Paul takes some of the pressure off Brian's shoulder because he is a leader as well," said Horan.
"Brian's often further out on the pitch and can't make important decisions at the breakdown so it's great to have someone like Paul back to do that.
"He's someone that leads from the front and really sets down a marker."
Victory over Wales would take the RBS 6 Nations title race down to the wire with Warren Gatland's side in the driving seat due to their healthy points difference.
Ireland were pipped to the crown by the narrowest of margins by France last year and Horan fears a repeat.
"Beating Wales would make things very interesting. All you can do is win the games and put yourself in with a shout," he said.
"Points difference will dictate what happens if everyone ends up on four wins. But we can't affect what other teams are doing.
"We can only win our own games. We had a huge disappointment last year but if we're in with a shout again this year it'd be great for us."