Daniel sued John Q. Carter Enterprises, Inc. d/b/a McDonald’s claiming that the defendant restaurant operator negligently failed to keep its premises in a safe condition, and that as a result of this negligence, she was injured when she slipped and fell in a puddle of liquid on the floor of the restaurant. Daniel appeals from the trial court’s grant of summary judgment in favor of the defendant.
Even assuming that Daniel was without knowledge of the liquid which caused her to slip and fall, the defendant restaurant operator was entitled to summary judgment because there is no evidence as to *224how the clear liquid was placed on the floor of the restaurant and no evidence that the defendant had actual or constructive knowledge of the liquid on the floor.
“[I]n order to state a cause of action in a case where the plaintiff alleges that due to an act of negligence by the defendant he slipped and fell on a foreign substance on the defendant’s floor, the plaintiff must show (1) that the defendant had actual or constructive knowledge of the foreign substance and (2) that the plaintiff was without knowledge of the substance or for some reason attributable to the defendant was prevented from discovering the foreign substance.” Alterman Foods v. Ligon, 246 Ga. 620, 623 (272 SE2d 327) (1980). In other words, it is only “ ‘when the perilous instrumentality is known to the owner or occupant and not known to the person injured that a recovery is permitted.’ [Cit.]” Id. at 622. Since there is no evidence and no claim by Daniel that the defendant had actual knowledge of the liquid in which she slipped and fell, Daniel’s claim must be based on a showing that the defendant had constructive knowledge of the presence of the liquid on the floor of the restaurant.
Two different classes of premises liability cases may be based on constructive knowledge. In the first class, “[constructive knowledge may be inferred where there is evidence that an employee of the owner was in the immediate vicinity of the dangerous condition and could easily have noticed and removed the hazard.” (Citations and punctuation omitted.) Winn-Dixie of Greenville v. Ramey, 186 Ga. App. 257, 259 (366 SE2d 785) (1988). Since there is no evidence that an employee of the defendant was in the immediate area of the hazard, Daniel’s claim falls into the second class of constructive knowledge cases. In the second class, “[liability based on constructive knowledge may also be established by showing that the owner failed to exercise reasonable care in inspecting the premises, but recovery under that approach requires proof of the length of time the dangerous condition was allowed to exist.” Hughes v. Hosp. Auth. of Floyd County, 165 Ga. App. 530, 531 (301 SE2d 695) (1983).
The issue in the second class of constructive knowledge cases “is whether, under the existing circumstances, [defendant’s] failure to have discovered the specific foreign substance prior to [the plaintiff’s] fall was the result of the breach of [the defendant’s] legal duty to inspect the premises. If so, an inference would arise from that breach of [the defendant’s] constructive knowledge of the presence of the [foreign substance] on its floor.” Food Giant v. Cooke, 186 Ga. App. 253, 255 (366 SE2d 781) (1988). In seeking summary judgment, the defendant has the initial burden of showing that this theory of recovery is not viable by demonstrating that it exercised reasonable care in inspecting the premises. Ramey, supra at 259. This burden may be carried by evidence of compliance with reasonable inspection proce*225dures. Mallory v. Piggly Wiggly Southern, 200 Ga. App. 428, 430 (408 SE2d 443) (1991). “Evidence establishing an adherence to customary inspection and cleaning procedures on the specific day in question is required; while proof of the mere existence of such customary procedures is insufficient. [Cit.]” Id. at 430; J. H. Harvey Co. v. Johnson, 211 Ga. App. 809, 810 (440 SE2d 548) (1994); Morris v. Ryan’s Family Steak Houses, 206 Ga. App. 369 (425 SE2d 362) (1992). Once a defendant demonstrates a lack of actionable constructive knowledge by compliance with reasonable inspection procedures, the burden shifts back to the plaintiff to show how long the foreign substance had been allowed to remain on the floor. Ramey, supra at 259. “ ‘Without such (proof) it would not be possible to determine whether the defendant had been afforded a reasonable time within which to inspect and remove the hazard.’ Banks v. Colonial Stores, Inc., 117 Ga. App. 581, 585 (161 SE2d 366) (1968). ‘(T)he plaintiff must show that the . . . substance was on the floor for a length of time sufficient for knowledge of it to be imputed to the defendant.’ Alterman Foods, [supra].” Gold & White, Inc. v. Long, 159 Ga. App. 259, 260 (283 SE2d 45) (1981). Of course, “[i]n the absence of evidence that [the defendant] conducted a reasonable inspection of the premises that would have discovered the foreign substance that caused the slickness on the floor, [the plaintiff would not be] required to present evidence establishing the length of time that the substance had been allowed to remain on the floor. [Cits.]” Jackson v. Wal-Mart Stores, 206 Ga. App. 165, 169 (424 SE2d 845) (1992).
The record in this case shows that the restaurant conducted a routine inspection of the floor shortly before Daniel slipped and fell, which revealed no liquid on the floor. According to Daniel, she arrived at the restaurant somewhere between 5:00 p.m. and 5:15 p.m., stood in line three to five minutes before she placed her order, waited “several more minutes” to receive her food, proceeded immediately to a counter to pick up some napkins and straws, and “maybe 10 seconds to 20 seconds” later arrived at the top of the steps where she stepped in the liquid and slipped and fell. In support of summary judgment, the defendant provided the affidavit and deposition testimony of the manager of the restaurant, who was on duty at the time of the fall. He stated that it was the normal procedure of the restaurant to inspect the floors every 30 minutes on the hour and half-hour by performing what was described as a “travel pass” of the entire restaurant. He stated that on the day Daniel fell, “the last time prior to the incident involving Mrs. Daniel when I would have instructed a crew person to perform a travel pass would have been at 5:00 p.m.” The manager further stated that there was no report of any liquid on the floor in the area where Daniel slipped and fell.
Accordingly, the defendant provided evidence of adherence to a *226reasonable inspection procedure on the day of the fall which revealed no hazard on the floor somewhere between ten to twenty-five minutes prior to the fall, depending on when Daniel arrived at the restaurant between 5:00 p.m. and 5:15 p.m. There was no evidence that the premises were unusually dangerous, and “[i]t is well settled that a proprietor is under no duty to patrol the premises continuously in the absence of facts showing that the premises are unusually dangerous.” Mazur v. Food Giant, 183 Ga. App. 453 (359 SE2d 178) (1987). This evidence was sufficient to shift the burden to Daniel to prove how long the liquid had been on the floor. Super Discount Markets v. Clark, 213 Ga. App. 132, 133-134 (443 SE2d 876) (1994); compare Burke v. Bi-Lo, 212 Ga. App. 115, 117 (441 SE2d 429) (1994) (burden did not shift to plaintiff where normal inspection procedure explained, but manager had no memory as to whether the inspection procedure had been adhered to on the day of the fall); Boss v. Food Giant, 193 Ga. App. 434, 436 (388 SE2d 37) (1989) (evidence failed to establish that any inspection had been made on the day in question, so burden never shifted to plaintiff); Ramey, supra at 259 (burden did not shift where defendant offered no evidence as to what inspection procedures, if any, were in effect and no evidence as to adherence to any inspection procedures).
There was no evidence as to how long the liquid had been on the floor of the restaurant. Accordingly, there was no proof that the liquid had been on the floor for a period of time sufficient for it to have been discovered by a reasonable inspection. Queen v. Kroger Co., 191 Ga. App. 249, 250 (381 SE2d 413) (1989). Since actual knowledge is not at issue and the record does not show that the defendant had any constructive knowledge of the hazard, the trial court correctly granted summary judgment in favor of the defendant. Smith v. Winn-Dixie Atlanta, 203 Ga. App. 565, 566 (417 SE2d 202) (1992); Johnson, supra at 810; Morris, supra at 369-370.
Judgment affirmed.
Beasley, C. J., Birdsong, P. J., Pope, P. J., Johnson, Blackburn and Ruffin, JJ., concur. McMurray, P. J., dissents. Smith, J., not participating.