EGGER D4 Adhesive is used for bonding the board to the joist and within the tongue and groove joint as well as for sealing nail heads and adjacent areas. 1 bottle will cover 3 sheets if used on the sheet and joists. If not used on joists, it will cover 5.5 sheets.
MDF 18mm is a composite panel product consisting of cellulosic fibres compressed with a synthetic resin or other ideal bonding system and joined together under extreme heat and pressure. For light carpentry projects, such as shelving and trim, 18mm MDF can be excellent.
Birch plywood is made from only Birch veneers of the same thickness, glued and laid up in alternating directions to the required thickness. It thus provides a superbly consistent strong panel with known engineering characteristics.