Owner sued waterproofing company in 2013 claiming its poor application of waterproofing materials on the roof of owner’s building caused leaks in the roof. The jury verdict was in favor of the waterproofing company. Though finding it was negligent, the jury concluded defendant’s negligence did not cause the leaks or other damage to the building. Several years later, owner sued the waterproofing company again under its warranty of materials and labor. This decision holds that the second suit was on the same cause of action as the first suit and so was barred by the res judicata impact of the first judgment. The defendant’s materials and labor had been the subject of the first suit. No new materials or labor had been supplied after the first judgment. Nor were the new leaks shown to be from a new source that couldn’t have been discovered during the first suit. The opinion criticizes California’s primary rights theory for determining the “cause of action” but follows it after checking the result against what it would have found under the Restatement’s transactional approach.