I’m going to say it again: If something is required by the Specifications, it’s required by the Contract.
A procedure or item specified in the Specifications is part of the Contract, just as much as if the procedure or item were specified in the Agreement. (The Agreement is what many people usually think of as the “Contract,” because it’s the particular document that gets signed by the Owner and the Contractor, and it has the Contract Sum indicated in it. But the Agreement is only ONE PART of the Contract.)
The Contract is made up of the Agreement, the Conditions of the Contract, the Drawings, the Specifications, etc. AIA Documents state this requirement most clearly; Owner-generated Agreements and Conditions of the Contract sometimes fall short of being explicit about this. (This is one of many good reasons to use AIA Documents instead of Owner-generated documents.)
This requirement is SO IMPORTANT that it makes up ARTICLE ONE of AIA Document A101-2007 (Standard Form of Agreement Between Owner and Contractor where the basis of payment is a Stipulated Sum), a very commonly used Agreement.
“The Contract Documents consist of this Agreement, Conditions of the Contract (General, Supplementary and other Conditions), Drawings, Specifications, Addenda issued prior to execution of this Agreement, other documents listed in this Agreement and Modifications issued after execution of this Agreement, all of which form the Contract, and are as fully a part of the Contract as if attached to this Agreement or repeated herein.” – from Article 1 of AIA Document A101-2007
I don’t think I can say this any more clearly.
But somehow, there are a number of Contractors out there who don’t seem to realize that the Specifications are part of the Contract, and there are even a few Architects out there who don’t seem to realize that the Specifications are part of the Contract that they are supposed to be administering during construction. An Owner agrees to pay a Contractor a certain sum, the Contractor agrees to provide the Owner with certain things indicated by the Drawings and Specifications and other Contract Documents, and, in a separate Agreement, the Architect and the Owner agree that the Owner will pay the Architect a certain sum, and the Architect will administer the Contract between the Owner and the Contractor. We all have contractual obligations during construction, and we all need to understand, and follow through on, all of those obligations.
Remember, if it’s in the Specs, it’s in the Contract.
Comments From a Spec Writer 
Some architects do know how important a spec really is. One of my clients responsible for construction document production and construction administration staff keeps telling me: “Dave, I don’t care what’s on the drawings. Give me a good spec and I will get what I want.”
Do you think he is relying on the contractor not reading the spec, and then enforcing it when needed?
If you’re saying “specs get no respect” I can wholeheartedly agree. Particularly troublesome when even architects gloss over them as secondary information. “Only if I have to” is the attitude many have for really reading & enforcing specifications.
I have lost count on the number of times one of my architect clients have commented that, “The specs have (again) saved our buttocks.”
Specifications are worth the price to get right the first time. Architects I respect the most are the ones that know when they need outside expertise – and go get it!