Dupré Vermiculite Products DSF

Dupré DSF is a superfine grade of vermiculite produced by expanding vermiculite ore into free-flowing, lightweight granules.

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Animal Feed

Completely non-toxic, inert and sterile when exfoliated, Dupré DSF is an outstanding support material for carrying a wide range of nutrients and medicines.

Friction Materials

Fibre free and completely safe, the benefits of using vermiculite in brake lining formulations are now well understood.

Horticulture

The water absorption and light reflection properties of DSF make it ideal for fine seed sowing and covering.

Industrial Uses

These are many and varied, and include:

•Gasket
•Seals
•Paint additives
•Resin fillers
•Fireproof boards and shapes
•Insulating firebricks
Floor screeds and Roof screeds

When combined with ordinary Portland cement they form a concrete ideal for many uses where low weight, excellent thermal insulation and fire resistant properties are all of particular value.

Recommended Mixes
Mixes	(Parts by volume)
Floor screeds	1:6 Portland cement:Dupré DSF Vermiculite
Roof screeds	1:8 Portland cement:Dupré DSF Vermiculite
Topping	1:4 Portland cement:sharp sand
Water content	Use 23 litres (approx 5 galls) of water per bag of Dupré DSF Vermiculite. To be judged by eye for sand:cement mix.
Coverage
	Quantities for 1m3 of placed DSF screed
1:6 mix	5.5 bags of cement and 11 bags of Dupré DSF Vermiculite.
1:8 mix	4.5 bags of cement and 11 bags of Dupré DSF Vermiculite.

Mixing

Small quantities may be mixed by hand but larger quantities must be mixed using a forced action mixer such as a paddle mixer. For hand mixing, combine the cement and vermiculite dry and add the water from a watering can with a fine rose nozzle. For machine mixing, combine the cement and water to form a thin grout then quickly add all the vermiculite. In either case mix quickly and thoroughly. The protective topping screed should also be thoroughly mixed by hand or in a forced action mixer.

Placing and compaction

Use the mixed DSF screed material as soon as possible after mixing. Place in position, overfilling by about 10% to allow for compaction, compact by lightly tamping and then strike off to level. If a monolithic topping is to be applied, brush on a creamy grout coat of cement and water and immediately apply, compact and finish the topping screed. This work must be completed within about 1 hour to ensure the layers bond properly.

Curing and protection

Cover the finished screed with polythene for the first few days, then allow to dry naturally. Protect the screed from mechanical damage, rain leakage, etc; until the final surface is laid. Repair any cracks or other damage prior to installation.

Specifications and standards of work

General guidance only is provided here and all work should be carried out in accordance with up to date British Standard Codes of Practice such as BS 8000: Part 9: 1989, BS 8204: Part 1: 1987.

Testing

The use of the BRE Screed Tester is not recommended for DSF screeds, but nail penetration tests may be suitable.