TARMAC TRUFLOW SELF LEVELLING SCREED

Tarmac Truflow Self Levelling Screed is an exceptional and consistent quality controlled anhydrite based self-levelling floor screed for use in floor levelling applications. The product is factory batched and delivered to site by truck mixer ready for immediate use. It can be pump applied to create a smooth and level surface for the application of floor coverings, tiles and other floor finishes.

Tarmac Truflow Self Levelling Screed is highly versatile and can be applied as a bonded or unbonded screed, as a floating screed over thermal or sound insulation and is also ideal for use in conjunction with underfloor heating systems.

It is suitable for use in most commercial and domestic buildings, in both new build and refurbishment applications and can be readily applied over installed electrical and other services.

Some Advantages of the Product
• Delivered Pre-mixed and ready for immediate application
• Allows an extremely rapid rate of application of up to 2000 m2 per day
• Laid only by Tarmac South approved licensees
• Guaranteed compressive strength of 30 N/mm2
• Accessible to foot traffic normally within 24 hours
• Self-compacting without segregation
• Permits designer to use lower minimum thickness compared to sand: cement systems
• Minimal need for joints
• Soundness category A according to BS 8204: Part 1 BRE Screed Test
• Class SRi surface regularity (_ 3mm in 3m length)

Physical Properties

Performance Characteristics
Speed of Application
This product permits extremely fast application rates to be achieved, and its easy handling and pumping characteristics allow up to 2000 m2 of screed to be laid per day.

Coverage per m3

Surface Regularity
A surface regularity of class SRi BS 8204: Part 1: 1987 can readily be achieved with this product. That is, the departure from the underside of a 3m straightedge resting in contact with the floor is _ 3mm.

Category of Use of Floor
The soundness categories of floors as described in BS 8204 for bonded and unbonded screeds are summarised below:

According to BS 8204: Part 1, soundness is assessed using the BRE screed tester which measures the in-situ crushing resistance of the floor. Tarmac Truflow Self Levelling Screed achieves < 2mm by this test and so readily meets the requirements of the most stringent category i.e. category A applications.

Minimum Thickness
For all floor types abrupt changes in screed thickness should always be avoided as these may lead to the formation of cracks.

Minimum Thickness Over Insulation

The maximum compressibility of the insulation must be 5mm.

Application
General
Site preparation and application of Tarmac Truflow Self Levelling Screed may only be carried out by licensees who have successfully completed Tarmac South's training programme. The product has not been designed to be used as a wearing surface. Tarmac Truflow Self Levelling Screed is not suitable for use in external or permanently wet areas.

The product should therefore not be applied to areas subject to prolonged wetting unless the screed is completely sealed with an impervious barrier.

Users must always refer to the guidance provided in the Safety Data Sheet i 08.

General Site Preparation
The building should be weather-tight before the screed is applied. Where appropriate, for example in ground floor applications, a damp proof membrane must be employed below the screed base. The floor area must be swept or vacuum cleaned and free from any projections.

For all applications a polyethylene foam border strip must be fixed all around the perimeter of the area to be screeded. The border must also be fixed around any upstands. If adjoining areas through doorways or other openings are not being screeded at the same time, border strip should be fitted and supported across these openings. In general the border strip should be at least 5mm thick. For under floor heating applications a 10mm thick border strip should be used.

Any structural joints must be extended through the Screed.

The product flows readily around pipes and conduit providing maximum contact without air pockets. The cover over conduits must be at least 25mm and above heating pipes at least 35mm.

For areas of sufficient size to require two truck mixer deliveries, care should be taken to fully mix the two deliveries at their interface.

Preparation of Unbonded Floors
Overlapped single sheet polythene sheeting of 150 micron minimum thickness (500 gauge) should be applied to the floor after all protrusions and dust have been removed. The polythene sheeting is intended as a debonding membrane and not a damp proof membrane. Where overlapped, the edges of the polythene sheet should be taped together. The polythene sheet should be fixed carefully at the perimeter of the floor and all upstands. Great care must be taken to avoid dirt or debris from contaminating the polythene sheeting after fitting.

Preparation of Floating Floors
Application on Thermal or Sound Insulation Tarmac Truflow Self Levelling Screed can be laid over thermal or sound insulation without the need for reinforcement. The lower thickness of screed required, compared to traditional sand and cement screeds, provides important weight and floor to ceiling height benefits. The thermal or sound insulation sheets should be butted tightly against each other and fitted right up to the perimeter of the floor. Overlapped and taped polythene sheet of 150 micron minimum thickness (500 gauge) should be laid on top of the insulation. The polythene sheeting is intended as a debonding membrane and not a damp proof membrane. The polythene sheet should be fixed carefully to the perimeter of the floor and all upstands. Great care must be taken to avoid dirt or debris from contaminating the polythene sheeting after fitting.

Application with Underfloor Heating Systems
Expert advice should be sought regarding the installation of the under floor heating system. The excellent flow characteristics of Tarmac Truflow Self Levelling Screed make it ideal for use with such heating systems since it flows readily around pipe work allowing maximum contact with the pipe work and is self-compacting. It is suitable for use with both electrical and water pipe under floor heating systems. Border strips minimum 10mm thickness must be fixed around the perimeter and all upstands. The heating system should not be turned on for at least 72 hours after application of the screed. Preparation of Bonded Floors Tilicon Truflow Self Levelling Screed can be used in bonded systems but it is usually preferable to apply the product as an unbonded or floating floor system.
Prior to application of a bonded floor, the surface must be shot blasted or scrabbled. Extra careful attention must be paid to ensuring that the surface is free from dust, vacuum cleaning usually being essential. Great care must be taken not to reintroduce dirt or dust onto the floor after cleaning.
The floor must be sealed with a suitable bonding agent prior to application of the screed.

Contact us for further advice.

Screed Preparation and Placing
Tarmac Truflow Self Levelling Screed is a factory produced product that is manufactured under strict quality control conditions. All materials are precisely weigh-batched, mixed and then delivered to site by truck mixer ready for immediate use. Further quality control testing is carried out on arrival at site. Tarmac Truflow Self Levelling Screed is then applied to the floor by Tarmac South approved licensees using conventional pump equipment.

Post Application
Curing
There are no specific curing requirements. However, protection from severe drafts and strong sunlight is necessary but some air movement through the building is certainly beneficial. The floor should not be covered by polythene sheeting and should not be subject to heating for the first 72 hours after application.

Sanding
The surface should be sanded lightly after 3 to 4 days to remove any fine laitance before bonded finishes are applied. Any resulting dust should be removed before application of the floor finish. The floor finish can then be applied as soon as the floor has dried sufficiently.

Drying Time
Normal Drying
The drying time determined according to the requirements of BS 8203 code of practice for installation of resilient floor coverings and BS 5325 code of practice for installation of floor coverings at 20CC and 65% relative humidity is <1 week/cm depth of screed.
Exact drying times are dependent on temperature, humidity and air movement through the building. Also any moisture in the floor below the screed will impair the drying rate of the screed unless a damp proof membrane has been installed between the two As a consequence, the level of moisture in the screed should always be checked according to BS 8203 or BS 5325 prior to application of the floor covering.

Forced Drying
Forced drying should not be applied to the floor within 72 hours of application. Further advice can be provided on request.

Finishing
The dried screed is suitable to take all types of floor finish but is not itself designed to be used as a wearing surface. Where a cement-based finish is to be applied, the screed surface should first be treated with suitable primer.