There is a reason why contractors need to review their contracts closely and the Washington Court of Appeals' decision in King County v Walsh Construction Company II LLC, No. 83787-7-1 (Wash. App. Ct. 2023) ("Walsh") highlights the importance of close contractual scrutiny. In Walsh, the Court held that the contractor could maintain its implied warranty defense to a claim that the contractor had an obligation to correct a failed pipeline. The implied warranty, also known as the Spearin Doctrine, holds that where a contractor is required to build in accordance with plans and specifications furnished by the owner, the owner implied guarantees that the plans are workable and sufficient.

However, where the construction contract provides an express warranty that the materials and equipment installed by the contractor will "operate satisfactorily under the plans and specifications of the owner" that express warranty will displace the implied warranty of design adequacy. In the Walsh contract, there was no such express warranty. In contrast, in the Walsh contract, the contractor disclaimed any obligations to provide design services or to maintain the pipeline in perfect condition for a specified period of time.

The bottom line is that in any warranty provision the contractor should consider the presence or absence of a warranty that the work will "operate satisfactorily under the plans and specifications of the owner." This is frequently expressed as a warranty that the materials are suitable for their intended purpose. When the owner's designer specifies the materials, the contractor should seek to have the warranty of suitability of materials eliminated and the owner should bear the responsibility for its designer's selection of materials.