Chris Coleman’s visitors were abject throughout and both sides look set for mid-table finishes this season.
Reading captain Matt Mills was able to play despite his sending off against Ipswich on Saturday as the club lodged an instant appeal while McDermott also recalled Jay Tabb, Jem Karacan, Church and Rasiak.
Church had the first effort on goal but shot wide from the edge of the area before the Royals took a 15th-minute lead.
Coventry lost possession cheaply while on the attack and Tabb nipped in to launch a counter attack down the right.
Jobi McAnuff carried the ball forward and when he crossed Rasiak arrived to volley home with the aid of a deflection that gave goalkeeper Keiren Westwood no chance.
Reading had found their rhythm and doubled their lead in the 22nd minute after another swift attack.
This time the threat came down the left and when full-back Ryan Bertrand made an overlapping run into the area he was tripped by Stephen Wright, leaving referee Andy Woolmer to point to the spot.
Usual penalty taker Gylfi Sigurdsson was rested on the bench so Church took responsibility and calmly sent Westwood the wrong way to make it 2-0.
Andy Griffin came close to a rare goal when he chanced his arm from 25 yards but the shot bent wide before Kebe made it three in the 40th minute.
Church was again involved, pulling out wide on the left flank before sending in a deep cross which evaded the Coventry defence and fell at the feet of Kebe.
The Mali winger has been in inspired goalscoring form since McDermott took over and crashed in his eighth goal in the last 14 games with a thumping low drive.
Coventry midfielder Aron Gunnarsson had the first chance of the second period but drilled his shot straight at Adam Federici in the Reading goal.
The visitors were on top and came close to getting a goal back in the 56th minute.
David Bell made ground down the right and found Freddie Sears in the area with a measured cross but Federici got down well to parry his volley around the post for a corner.
Sammy Clingan then found Gunnarsson who headed over as Coleman’s side continue to press before Rasiak powered a header over the top at the other end.