weberfloor 4160 fine flow rapid

Prepare

The surface strength of the substrate must be greater than 1N/mm2

It is essential the substrate is suitably prepared and primed with weberfloor 4716 primer prior to installing the Weber floor screed.

The substrate should be clean, free from dust, grease and other impurities that might prevent adhesion.

Walls and any upstands (pillars, columns etc) should be isolated with 10 x 100mm foam.

Large irregularities in the substrate (>30m) should be filled in with a application of weberfloor 4360 base flow rapid, this should be allowed to harden and then primed before application of weberfloor 4160 fine flow rapid can begin.

Holes and leaks in the substrate should be sealed. The substrate should be vacuum cleaned, prepared and primed with weberfloor 4716 primer according to the instructions on the data sheet.

Priming improves the screed's adhesion to the substrate and prevents the formation of air bubbles and dewatering of the screed. Priming also improves the flow properties of the screed. Dry and very porous substrates (cast-in-situ concrete floors) may need to be treated twice. If the screed is applied in more than one layer, each layer must be primed.

Mix

weberfloor 4160 fine flow is mixed with clean water using an automatic screed mixer approved by Weber.

The material is mixed with 20% water, which corresponds to 5.0 litres per 25 kg bag. It is important to add only the specified amount of water as excess water will reduce strength, increase shrinkage and encourage segregation. Whilst mixing, the water content should be checked continuously by the flow ring test to ensure that the material is correctly mixed and free from separation and lumps of powder. The flow rate should be between 240-255mm. Conversely, reduced water content increases viscosity. The temperature of the mix should ideally be between +15°C and +20°C.

For manual mixing thoroughly mix with using a slow speed electric mixer (500 rpm) for at least two minutes. Allow to stand for 2 minutes.

Apply

Light ventilation in the working area is necessary but windows and door openings must be closed sufficiently to avoid draughts during and for 3 days after application.

During application, and for at least 1 week afterwards, the substrate and ambient temperature should not fall below +10°C or rise above +25°C. The relative humidity of the substrate must be <95%.

To achieve the best finish, the floor area should be divided into bays of 6 to 8 metres depending on pump capacity and application thickness. weberfloor 4965 barrier foam should be used to form bays and stop ends. Pumping is carried out in sections so that a new section is pumped as quickly as possible and to maintain a wet edge. A wide serrated spatula or spike roller should be used to assist the self-levelling process.

Overlay

weberfloor 4160 fine flow rapid is compatible with most common floor finishes and adhesives.

It should not be painted or used without a floor finish.

Drying time

The screed can receive foot traffic after a drying time of 1 - 3 hours at an ambient temperature of +20°C. If necessary, the surface can be ground after 2 days following application. Floor covering can be installed after 1 - 2 days depending on layer thickness and drying conditions.

High humidity of the substrate and poor drying conditions prolong the setting time.