In short
Before a material is installed, the contractor submits it with its data sheet, certificates and a sample; the consultant checks it against the specification and approves, rejects or asks for changes. Approval before installation is what keeps a substitution from becoming a permanent defect.
Key points
- A submittal is the contractor's proposal of a specific product, with data sheets, certificates and samples.
- The consultant checks it against the specification and the drawings, not against the price.
- Approved samples become the reference for everything delivered later.
- Deliveries are checked against the approval before they are used.
A specification describes what a building should be made of. The submittal process is how that description turns into real products on site, and it is one of the places where supervision protects the owner most directly.
What a submittal is
Before ordering a material or system, the contractor submits the exact product proposed: the manufacturer, the data sheet, test certificates, and where useful a physical sample. Waterproofing, tiles, stone, paint, sanitaryware, doors, insulation and many other items go through this step.
What the consultant checks
The submittal is checked against the specification and the drawings: performance, dimensions, finish, compatibility with neighbouring materials, and compliance with requirements that apply. The answer is approved, approved with comments, or rejected with reasons.
Samples are references
An approved sample or mock-up becomes the reference for what is delivered and installed afterwards. If a delivery does not match it, the delivery is questioned, not the sample.
Checking deliveries
Materials arriving on site are checked against the approval: product, batch, condition and storage. Waterproofing membranes left in the sun or cement bags stored in the open are problems that are easy to prevent and hard to undo.
Why skipping it is expensive
Without approval, a substitution can be installed and covered before anyone notices. At that point the choice is between accepting a lower-performing product for the life of the building or removing finished work. Material compliance checks are part of Nation’s construction supervision for this reason.
Questions
Can the contractor propose an alternative product?
Yes, through a submittal. An equivalent product can be approved if it meets the specification; the decision should be made on paper before it reaches site.
Who keeps the approved samples?
They are kept on site or in the consultant's office as the reference for inspections and handover.