This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
If an agent or employe has been guilty of conduct for which he could be discharged, the act of the employer in continuing to accept his services, with knowledge of the facts, operates as a waiver of such ground of discharge.1 If A has agreed to pay a certain sum to B for the performance of certain work, and a greater sum upon the happening of some specific event,2 as upon condition that the adversary party refrain from the use of intoxicating liquor,3 and such condition subsequent is broken, A's subsequent promise to pay the full amount of such compensation in spite of such breach of condition is a waiver of such condition. The default of the contractor under a construction contract, in furnishing material other than that provided for in the specifications, is waived by the act of the adversary party in accepting such work and in paying for it, with knowledge of the facts.4 A clause in a building contract, requiring the contractor to give bond, is waived by allowing him to construct the building without giving such bond.5 The same rule applies where a provision that no subcontracts shall be let without the owner's written consent is waived by the owner's permitting subcontractors to do part of the work without objection.6 Omission to give notice of a meeting to determine questions of performance of a building contract is waived by the presence of the representatives of the party to whom such notice was not properly given.7 If A is to complete a tramway by a certain date, and haul logs for B, and A does not complete the tramway by the date specified, the fact that B urges A to complete it waives a right given to B by the terms of the contract to forfeit the contract to take charge of and complete the tramway if A does not complete it by the time agreed upon.8 Acceptance by an engineer or architect who is authorized to represent the owner in a building contract, waives such defects in the material tendered in performance of the contract as could be discovered by exercising ordinary care.9 Failure to make a test which could have determined the question of performance, has been held to waive possible defects, the existence of which could have been proved or disproved by such test.10
Missouri. Murray v. Farthing, 6 Mo. 251; Gelatt v. Ridge, 117 Mo. 553, 38 Am. St. Rep. 683, 23 S. W. 882.
New York. Vanderbilt v. Eagle Iron Works, 25 Wend. (N. Y.) 665; Weston v. Syracuse, 158 N. Y. 274, 70 Am. St Rep. 472, 43 L. R. A. 678, 53 N. E. 12; St. Regis Paper Co. v. Santa Clara Lumber Co., 186 N. Y. 89, 78 N. E. 701; Clark v. West, 193 N. Y. 349, 86 N. E. 1; Wolfert v. Caledonia Springs Ice Co., 195 N. Y. 118, 21 L. R. A. (N.S.) 864, 88 N. E. 24.
Rhode Island. Kerr v. Armstrong, - R. I. -, 110 Atl 416.
Tennessee. Tennessee Coal, Iron & Railroad Co. v. Wilson (Tenn. Ch. App.), 46 S. W. 342.
"It can hardly be open to dispute that whatever the parties to a con-tract consent to treat and accept as a performance of its conditions will so be treated by the court." Wells v. Hocking Valley Coal Co., 137 la. 526, 114 N. W. 1076.
Arkansas. Fitzgerald v. La Porte, 64 Ark. 34, 40 S. W. 261.
California. Griffith v. Happersberger, 86 Cal 605, 614, 25 Pac. 137, 487.
New York. Smith v. Alker, 102 N. Y. 87, 5 N. E. 791; Flaherty v. Miner, 123 N. Y. 382, 25 N. E. 418.
Texas. Linch v. Elevator Co., 80 Tex. 23, 15 S. W. 208.
Wisconsin. Laycock v. Parker, 103 Wis. 161, 79 N. W. 327.
3 Goodspeed v. United Shoe Machinery Co., 141 Mich. 672, 104 N. W. 982.
4 Bluthenthal & Bickart v. May Advertising Co., 127 Md. 277, 96 Atl. 434.
1 Alabama. Troy Fertilizer Co. v Logan, 90 Ala. 325, 8 So. 46.
Illinois. Butterick Publishing Co. v. Whitcomb, 225 111. 605, 8 L. R. A. (N. S.) 1004, 80 N. E. 247.
Massachusetts. Daniell v. Boston & Maine By., 184 Mass. 337, 68 N. E. 337.
Nebraska. Nesbit v. Giblin, 96 Neb. 369, L. R. A. 1915D, 477, 148 N. W. 138.
Wisconsin. Bast v. Byrne, 51 Wis. 531, 37 Am. Rep. 841, 8 N. W. 494; Tickler v. Andrae Mfg. Co., 95 Wis. 352, 70 N. W. 292.
2 Clark v. West, 193 N. T. 349, 86 N. E. 1.
3 Clark v. West, 193 N. Y. 349, 86 N. E. 1.
4 Owensboro City R. Co. v. Barber Asphalt Paving Co. (Ky.), 107 S. W. 244.
5 Devlan v. Wells, 65 N. J. 213, 47 Atl. 467.
See to the same effect. Ford v. Dyer, 148 Mo. 528, 49 S. W. 1091, and Kerr v. Armstrong, - R. I. -, 110 Atl. 416.
6 Danforth v. Tennessee ft Coosa Ry., 93 Ala. 614, 11 So. 60.
7 Bloomington Hotel Co. v. Garth-wait, 227 111. 613, 81 N. E. 714.
8 Thompson Lumber Co. v. Howard (Ky.), 57 S. W. 615; Howard v. Thompson Lumber Co., 106 Ky. 566, 50 S. W. 1092.
9 Laycock v. Moon, 97 Wis. 59, 72 N. W. 372; Ashland Lime, Salt ft Cement Co. v. Shores, 105 Wis. 122, 81 N. W. 136.
10Peck-Williamson Heating ft Ventilating Co. v. McKnight, 140 Tenn. 563, 205 S. W. 419.
Other illustrations of acceptance with full knowledge of the facts, amounting to a waiver of breach as a ground for discharge, are found in contracts for constructing waterworks,11 for installing plumbing,12 for installing a heating plant,13 for paving streets and alleys,14 constructing ditches,15 constructing a building,16 or a party wall,17 or digging a well, even if the supply of water subsequently fails.18