Is a waiver of the right to arbitrate binding upon the appellate court?

[256 Cal.App.2d 260] It is settled that the question of waiver of the right to arbitrate is one of fact for the trial court; that where the arbitration agreement does not specify a time within which arbitration is allowed, what constitutes a reasonable time is likewise a question of fact, depending upon the situation of the parties, the nature of the transaction and the facts of the particular case; that the trial court's finding of waiver is binding upon an appellate court if supported by substantial evidence. (See Sawday v. Vista Irrigation Dist. (1966) 64 Cal.2d 833, 836, 52 Cal.Rptr. 1, 415 P.2d 816, and authorities therein cited.)