The issue in this appeal is whether the trial court erred in not granting the motion of defendant Alabama Power Company (hereinafter "APCo") for a directed verdict at the close of the plaintiff's case.

The plaintiff, Donald Thomas Williams, was a sheet metal worker employed by Combustion Engineering Company, which was hired by APCo to perform boiler maintenance and repair at APCo's Barry Steam Plant in Mobile County. Williams was working on a scaffold, which consisted of two 2 x 12 boards, the outer ends of which were supported on metal handrails. At a point where the two boards overlapped in the middle, they were supported on a one-inch metal pipe leading out of the boiler, and known as an "impulse line," a low-pressure line that led to a meter and served as a means of measuring pressure inside the vessel. The scaffold had been erected by other Combustion Engineering employees. As plaintiff Williams and another Combustion Engineering employee were using the scaffold, the impulse line supporting the center of the scaffold broke, and the scaffold collapsed. There is no question that the impulse line was not intended for supporting scaffolds, although there was some testimony that pipes are sometimes used by workmen as scaffold supports. The impulse pipe had rusted on the inside. As a result of the collapse of the scaffold, Williams fell and received a dislocated right shoulder, cuts, and abrasions, and he experienced some permanent disability.

Williams sued APCo, alleging that APCo had reserved the right of control over the manner of Combustion Engineering's employees' work, thus creating a duty to provide Williams with a safe place to work, that APCo voluntarily undertook to inspect the work site for safety and did so negligently, and that APCo negligently failed to warn Williams or Combustion Engineering of an alleged latent defect on the premises. At the close of Williams's case, APCo moved for a directed verdict on all three claims; that motion was denied. At the close of all the evidence, APCo again moved for a directed verdict. At that time, the trial court granted APCo's motion as to the claim that APCo had reserved the right of control over the manner of the work, but denied it as to the other two claims. Those two claims were submitted to the jury, and the jury returned a verdict for Williams in the amount of $230,000. APCo filed a motion for judgment notwithstanding the verdict, or, in the alternative, for a new trial. The trial court denied that motion, and APCo appealed.

A motion for directed verdict tests the sufficiency of the opponent's evidence. Coburn v. American Liberty Ins. Co.,341 So.2d 717 (Ala. 1977). A post-trial motion for JNOV, like a trial motion for *Page 591 directed verdict, is the proper procedural device for challenging, among other things, sufficiency of the evidence, and it permits the trial court to revisit its earlier ruling denying the motion for directed verdict. Barnes v. Dale,530 So.2d 770, 776 (Ala. 1988). On a motion for JNOV, the evidence must be viewed in a light most favorable to the non-moving party. Mallory v. Hobbs Trailers, 554 So.2d 966, 969 (Ala. 1989). A directed verdict is proper only where there is a complete absence of proof¹ on an issue material to the claim or where there are no disputed questions of fact on which reasonable people can differ. Ford Motor Co. v. Phillips,551 So.2d 992, 994 (Ala. 1989); Caterpillar Tractor Co. v. Ford,406 So.2d 854, 856 (Ala. 1981).

Regarding Williams's claim that APCo voluntarily undertook to inspect the premises and inspected them negligently, this Court has stated that in a suit of this type, the plaintiff must prove (1) that the defendant had undertaken to inspect the site, particularly the area in which the injury-causing hazard is located, (2) that the defendant performed such inspection negligently, and (3) that such negligence proximately caused the injuries. Columbia Engineering Int'l, Ltd. v. Espey,429 So.2d 955, 965 (Ala. 1983); Pate v. United States Steel Corp.,393 So.2d 992, 995 (Ala. 1981); Hughes v. Hughes,367 So.2d 1384, 1387 (Ala. 1979). The defendant's contractual right to enforce safety if a violation is observed does not, alone, constitute a voluntary assumption of the duty to inspect for safety. 429 So.2d at 966. Also, the defendant's having employees on the site to monitor contract compliance by the independent contractor will not impose a legal duty of safety inspection upon the defendant. 429 So.2d at 967-68.

After a review of the record, it is apparent to us that most of the evidence relied upon by Williams on his negligent safety inspection claim was adduced after the plaintiff had rested, and, therefore, after the defendant had made its motion for a directed verdict.² The evidence produced during the plaintiff's case consists of hypothetical questions and answers that show no more than that if one of APCo's employees saw a scaffold supported by an impulse line, then it would be his job to point it out to Combustion Engineering.³ The evidence *Page 592 produced by Williams shows only that APCo employees were on site to insure contract compliance, that none of them undertook to inspect for safety, and that none of them saw or inspected the scaffold in question.⁴

After our review of the evidence, we hold that there was no evidence produced by Williams that goes to prove that APCo voluntarily undertook to inspect the work site or the area of the scaffold in question. Therefore, the trial court erred in submitting this claim to the jury.

As to Williams's claim of a failure to warn of a latent defect, the record shows that Williams did not produce a scintilla of evidence that APCo knew, or should have known, of the dangerous condition of the impulse line pipe supporting the scaffold. There is no evidence that APCo approved the use of impulse lines for supporting scaffolds or that APCo knew that Combustion Engineering had erected this scaffold on this impulse line. Indeed, Williams's evidence showed that interior corrosion of pipes of this type was common knowledge among engineers in the industry; thus, Combustion Engineering had knowledge of the pipe's potential danger equal to the knowledge of APCo, and, yet, Combustion Engineering placed this scaffold on this pipe notwithstanding its knowledge of the danger. Williams did produce evidence that APCo employees had been near the scaffold and that one of these employees could have seen that the scaffold was supported by the impulse line, but clearly the evidence was not of the type and quality that this Court has held sufficient in such cases as Hodge v. UnitedStates Fidelity Guaranty Co., 539 So.2d 229 (Ala. 1989), andUnited States Fidelity Guaranty Co. v. Jones, 356 So.2d 596 (Ala. 1977), two cases relied upon by the plaintiff. There is no duty to warn an invitee who has equal or superior knowledge of a potential danger. Quillen v. Quillen, 388 So.2d 985, 989 (Ala. 1980). Further, a premises owner does not owe a duty of care to employees of an independent contractor with respect to working conditions arising during the progress of the work on the contract. Weeks v. Alabama Electric Coop., Inc.,419 So.2d 1381, 1383 (Ala. 1982). Here, during the course of performing the work called for in the contract, Combustion Engineering placed this scaffold on the impulse line without APCo's knowledge or consent. Therefore, the trial court also erred in submitting Williams's failure-to-warn claim to the jury.

For these reasons, we hold that the trial court erred in not granting APCo's motion for a directed verdict on all claims at the close of Williams's case and in not granting APCo's motion for JNOV. Therefore, the *Page 593 judgment of the trial court is reversed and judgment is rendered in favor of APCo.

REVERSED AND JUDGMENT RENDERED.

HORNSBY, C.J., and ALMON, ADAMS and STEAGALL, JJ., concur.