Board grade is what you paid for, and the wet areas are wet-grade
Why — act while you have leverage
Plywood grade is the single biggest cost difference inside a kitchen and the easiest to substitute. Commercial ply behind a sink swells, delaminates and takes the whole unit with it.
What to look at
- The IS stamp on the delivered sheets, photographed
- Wet-grade board in kitchen, bathroom and utility units
- Cut edges sealed rather than left raw
Documents to ask for
- Photographs of the IS grade stamp on delivered boards
How to check it yourself
Plywood is graded — BWR and BWP under IS 303, marine grade under IS 710 — and the grade is stamped on the sheet. Check the stamp on the boards actually delivered, not the quotation. Anything in a kitchen, a bathroom or a utility area should be the wet-area grade the quotation says you bought.
Where this comes from: IS 303 — Plywood for general purposes (MR / BWR / BWP grades); IS 710 — Marine plywood (indian standard or building code)