expertise and therefore failed to look to the proper yardsticks as developed in our deci-sional law.
In view of the above, the witnesses Cash and Adler, obviously educated and experienced in the field of engineering, should have been allowed to state their opinions as to such matters as the suitability of the roofing materials, the quality of the workmanship involved, the condition of the roof, and the need for replacement.
On appeal, the defendants take the position that even if Cash and Adler were qualified as experts, many of plaintiff’s questions were objectionable as improper hypo-theticals not containing sufficient facts.
We cannot agree. Many of the objections which were sustained on these grounds were actually directed to matters within the personal knowledge of the experts due to their inspection of plaintiff’s roof. Thus, they were qualified to state their opinions without the employment of hypothetical questions. Gamble, McElroy’s Alabama Evidence § 130.01 (3rd ed.). Moreover, a hypothetical question is not objectionable merely because it does not contain all facts in evidence which might tend to affect the answer. Clutts v. Clutts, 54 Ala.App. 43, 304 So.2d 599 (1974). When the evidence as elicited is in conflict, the questioning party should state only the facts which tend to support his own' theory of the cause. Gamble, McElroy’s Alabama Evidence, supra.
Plaintiff’s final evidentiary complaint centers around the trial court’s refusal- to allow certain testimony from Anthony Romeo, its manager of facilities planning, who also had considerable experience in the area of roofing. The court ruled Romeo was not an expert in this field and refused to allow his testimony as to the value of the defective roof.
While we are not prepared to say the trial court abused its discretion in finding Romeo was not an expert, Gregarth, supra, it nevertheless erred in precluding this testimony.
Section 12-21-114, Code of Ala.1975, provides:
Direct testimony as to the market value is in the nature of opinion evidence; one need not be an expert or dealer in the article, but may testify as to value if he has had an opportunity for forming a correct opinion.
The witness Romeo was clearly shown to have had sufficient opportunity for forming a correct opinion. He was responsible not only for the original construction of plaintiff’s plant but also for the reroofing. He made numerous inspections of the roof and received all reports of plaintiff’s technical consultants.
By the unambiguous words of the statute, there was no requirement that the witness be an expert in order to testify as to value. Alabama Power Co. v. Allen, 218 Ala. 416, 118 So. 662 (1928). The exclusion of the proffered testimony clearly worked an injury to plaintiff’s cause, and is therefore subject to our review and grounds for reversal. See, Blount County v. Campbell, 268 Ala. 548, 109 So.2d 678 (1959).
Considering the above in the totality of its effect, we conclude plaintiff is correct in its assertions on these evidentiary matters. It is within the province of the jury to ascertain the amount of damages, Alabama Power Co. v. Thompson, 250 Ala. 7, 32 So.2d 795 (1947), and the excluded testimony and documents were admissible as an aid in arriving at their true measure. Arrick v. Fanning, 35 Ala.App. 409, 47 So.2d 708 (1950). See also, Walker Manufacturing Co. v. Henkel Construction Co., 346 F.Supp. 621 (N.D.Iowa 1972).
II
As indicated, plaintiff was also erroneously denied the opportunity to put on proof as to the causes of the roof’s failure. We now turn to the effects of this error on plaintiff’s case against the other defendants, and while so doing, consider the propriety of the directed verdicts on legal as opposed to evidentiary grounds.
A. JOHNS-MANVILLE
Plaintiff contends the trial court erred to reversal in granting defendant Johns-Man-