Home > Companies > Alumasc Building Products Ltd > Drainage mat DBV12

Drainage mat DBV12 is a studded lightweight drainage layer, manufactured from thermoformed recycled polyethylene, with a polyester fleece attached to the upper face. The product allows aeration of the substrate and multidirectional drainage on the underside.


Install by loose laying onto the root resistant membrane (overlaid with a moisture retention mat) or against the exterior face of foundation walls. The polyester fleece must be uppermost. Butt joint the boards and overlap the 100 mm polyester fleece selvedge. Panels can be cut with a heavy duty knife or a small toothed saw to fit around protrusions. Overlay with appropriate substrate.

Standard product features


  • Drainage layer: Black.
  • Polyester fleece: Brown.


12 mm.

Panel size:

20 x 1 m.

Dry weight:

1.5 kg/m².

Water storage capacity:

1 litre/m².

Compressive strength:

> 300 kN/m².

Waterflow rate:

  • At 10% slope: 1.4 litres/second/m².
  • Vertical: 3.8 litres/second/m².

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-65-50/354 Plastics or rubber studded sheets

NBS Specification

NBS Buliding logo
This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Alumasc Building Products Ltd


+44 (0)1744 648400

Product reference

Drainage mat DBV12

Manufacturer details

White House Works,
Bold Road,
St Helens,
Merseyside, WA9 4JG
Tel +44 (0)1744 648400
Fax +44 (0)1744 648401
NBS Plus