1) After a thorough car inspection, the mechanic declared the engine to be sound as a roach.

2) Despite its battered appearance, the old house was surprisingly sound as a roach structurally.

3) The student's argument was sound as a roach and convinced everyone in the debate.

4) The building withstood the earthquake because its foundation was as sound as a roach.

5) The veteran soldier's strategy was sound as a roach and led his team to victory.

6) The investment advisor assured her clients that the company's financials were sound as a roach.

7) The boat may look rickety, but its hull is as sound as a roach, making it safe for sailing.

8) The antique watch was still ticking after years of neglect, proving its mechanism was sound as a roach.

9) The doctor confirmed that the patient's heart was sound as a roach after conducting various tests.

10) Despite being surrounded by chaos, her decision-making was as sound as a roach.