FAQ

TAL Screedmaster is not recommended for use over underfloor / undertile heating installations. Suitably modified underlayment compounds should be used in this instance, either TAL Superscreed trowel-applied underlayment or TAL Superscreed SL self-levelling underlayment. These must be mixed with TAL Screedbinder for enhanced flexibility.

It must however be noted that the addition of TAL Screedbinder could affect the flow characteristics and self-levelling properties of TAL Superscreed SL. If TAL Screedbinder is to be incorporated in the mix, the mix ratio should be increased to 5.5L.

Moisture must be controlled by installing a suitable vapour barrier system prior to the TAL Screedmaster application. Moisture testing should be conducted with a suitable moisture meter, and these readings accurately determined and recorded. It should however be noted that whilst a substrate may show as being ‘dry’ during testing, there are many contributing factors that can influence when and how water/moisture builds up below a building. These include changes in surface run off, high and/or fluctuating moisture levels due to high water tables, seasonal changes, alterations or excavations in and around building structures and sometimes even age plays a role in where or how water pressure occurs below a building. This could compromise the integrity of the underlayment compound and flooring installation, particularly vinyl tiles and sheeting, over time. Moisture barrier systems, such as TAL VaporStop HB and TAL Vapourscreen WB, are epoxy moisture and vapour barriers formulated to produce high crosslinking density barrier coats that reduce the risk of debonding of coverings due to high levels of moisture in the substrate and high moisture vapour emission rates (MVER).

The following factors can contribute towards cracking of TAL Screedmaster:

• Incorrect background preparation and priming.
• Over- or under-watering of the product during mixing.
• Product adulteration, ie adding sand or other materials to the mix.
• Too-rapid drying from direct sunlight and/or drying air or winds during application, and within the first 48 hours of curing, will result in drying-shrinkage cracks forming in the self-levelling screed.
• Reflective cracking of product installed over cracks/joints in the substrate, and/or covering two different substrate materials.

TAL Screedmaster is designed to be used as an underlayment compound, to achieve the smooth and flat surface required for the installation of floor coverings, and therefore should be covered with a suitable floor covering such as vinyl tiles or sheeting, carpets, laminate flooring, etc.
In residential applications, when applied at a minimum application thickness of 5mm, TAL Screedmaster can be installed as a ‘final finish’ provided it is sealed with a suitable sealer, such as TAL PUD Sealer high-performance polyurethane sealer. Maintenance sealing should be undertaken as and when required.
It must also be noted that variation in colour can occur due to the installation techniques, eg trowel marks, water marks, using different batches, etc.

This will depend on a number of factors, such as the quality and level of the substrate, the size of the installation area, and the size and competency of the installation team.
A proper floor level survey should be conducted, and all highs and lows marked. It is usually quicker, and more cost-effective, to grind down all highs and ridges.
Significant lows should be addressed, by remedial filling using a suitable rapid-setting patching and repair compound. This will minimise the quantity of self-levelling underlayment compounds.
TAL Screedmaster has excellent flow properties and is ideal for installation by pump over large areas. By this method, screeding rates are greatly increased.
TAL Screedmaster can be walked over after only 3 hours (at circa 3mm thickness). Floor coverings can be installed after 24 hours, depending on application thickness and site and ambient conditions.

TAL Screedmaster is not recommended for external applications, as ongoing exposure to moisture could compromise the integrity of the product over time.
TAL Superscreed mixed with TAL Screedbinder should be used for external applications if a thin build is required, or TAL SlabPatch Flowable, a fluid micro concrete, should be used for builds exceeding 6mm.

TAL Screedmaster can be mixed and applied manufally, or by pump.

TAL Screedmaster can be applied from 3mm up to 16mm in a single operation.
If greater builds are required, this should be done once the first layer has been allowed to dry for 24 hours. The existing layer should be primed with a coat of TAL Floor Primer before applying the next layer.

Screeds are typically sand-cement mortars consisting of OPC and graded sand/aggregate. These should be applied at a minimum thickness of 25mm (bonded) or 50mm (unbonded). Conventional sand-cement screeds should be allowed to cure for a minimum of 4 weeks before floor coverings are installed.
As the name suggests, self levelling screeds have good flow properties and are particularly suited for installation by pump over large areas.
Whilst self-levelling underlayments can be applied in much thinner builds than conventional sand-cement screeds, their maximum application thickness is limited.
Self-levelling underlayments are ‘self-compacting’ and don’t require any physical compaction other than the use of suitable rakes or spreaders to facilitate the self-levelling process. Spiked rollers should be used to remove any entrapped air and reduce the risk of pinholes forming.
ecause of their flow properties, self-levelling compounds are not suitable for floors where falls are required for drainage in ‘wet’ areas such as shower rooms and wet changing facilities in gyms etc. In addition, certain types of self levelling screeds are not suited for these types of applications because of their unsuitability for exposure to water.

The correct background preparation and priming is essential to ensure a sustainable installation.
Porous surfaces may ‘leach’ the mixing liquid out of the TAL Screedmaster mix, which will not only compromise the integrity and performance of TAL Screedmaster and result in a weak, friable product, and could also result in ‘pin holes’ forming in the surface. TAL Floor Primer is designed for priming of porous substrates.
Smooth and dense substrates, such as powerfloated concrete or screed, must be primed – using TAL Primercoat or a TAL Floorkey + TAL Rapidfix slurry priming coat – to ensure a good bond onto the substrate and prevent the Screedmaster from delaminating from the substrate.

No – adding sand, or cement, to the mix is considered product adulteration and TAL Screedmaster will not perform to its optimum design capabilities. Cracking will most certainly occur if adulterated.