Description
LAYBOND 78 HT is a high temperature, non-staining, copolymer emulsion
designed for bonding highly plasticised PVC backed floorcoverings. It is white in
colour and has a trowellable consistency.

Uses
LAYBOND 78 HT is used for bonding PVC backed carpets and PVC (vinyl)
floorcoverings to porous substrates, such as most concrete surfaces, chipboard,
hardboard, plywood and smoothing compounds.

It is suitable for use with underfloor heating systems. However, the heating
should be switched off at least 48 hours before and after installation of the
floorcovering.

Preparation
Relevant Standards:

All phases of the installation should comply with the latest editions of the
following standards:-
BS CP102 Code of Practice for protection of buildings against water from the
ground.

BS 5325 Code of Practice for installation of textile floorcoverings.

BS8203 Code of Practice for installation of sheet and tile flooring.

Sub-floor

The sub-floor should be clean, structurally sound, dry and free from
contaminants, including surface hardeners and additives that may hinder
adhesion. It should also have an effective damp-proof membrane and be suitably
dry to receive a bonded floorcovering.

The only British Standard approved test for dryness is by properly calibrated
and insulated hygrometer giving a reading of less than 75% RH. Where this
has not been achieved the use of either LAYBOND HYDROTITE or LAYBOND
SEALDECK surface membranes will suppress residual moisture in power floated
concrete slabs or sand/cement screeds provided that a base dpm has been
incorporated. Please refer to the relevant data sheet for full information.

Any deep indentations in the sub-floor should be repaired using LAYBOND
PLYCORAPID followed by a standard application of a LAYBOND SCREEDMASTER
SMOOTHING COMPOUND.

Existing Floorcoverings

All existing floorcoverings must be removed using a WOLFF floor stripper or
equivalent.

Smoothing Compounds

Where floors require smoothing, a LAYBOND SCREEDMASTER SMOOTHING
COMPOUND should be applied at a minimum thickness of 3mm. Where a
concrete base has had a surface treatment, this should be mechanically removed
prior to smoothing compound application.

Priming
Surfaces must be thoroughly cleaned (preferably vacuumed) and be smooth,
dry and free from contaminants. Porous surfaces and boards should be primed
using LAYBOND ISOBOND (diluted 1:6 with clean water) and allowed to dry.

§ This is particularly important with hardboard, chipboard and plywood.

Application

Porous Surfaces

LAYBOND 78 HT should be spread evenly over the floor surface with a triangular
notched trowel cut 1.5mm deep at 5mm centres. For coarse or embossed
backings, the notch size should be increased to 2mm deep at 6mm centres,
or deeper if recommended by the manufacturer.

The adhesive should be spread with a sweeping motion at a 60º angle and the
floorcovering placed into the adhesive while it is still wet. Even pressure should
be applied to ensure good overall contact. Do not apply more adhesive to an area
greater than can be covered within the open time (typically 10-20 minutes,
though this depends on ambient conditions and porosity of floor). If, while cutting
around perimeters the adhesive goes past its open time, it may be necessary to
carefully apply more adhesive. As LAYBOND 78 HT has no tack, floorcovering
displaying significant curl at the edges may require temporary weighting.

Non-Porous Surfaces

When laying onto non-porous or low porosity surfaces eg.asphalt, LAYBOND
SCREEDMASTER 2 LATEX SMOOTHING COMPOUND should be overlaid
at a minimum thickness of 3mm as this will provide an absorption layer for the
LAYBOND 78 HT. Application can then proceed as for porous surfaces.

Finishing
It is essential to ensure good overall contact between the floorcovering and the
adhesive. This may be achieved by use of a suitable WOLFF roller or other method
recommended by the floorcovering manufacturer.

Any LAYBOND 78 HT on the surface of the floorcovering should be removed
immediately with a damp cloth.

Safe Handling Precautions
Flammability: .

Skin Contact: Occasional contact is unlikely to have an adverse effect except
on particularly sensitive skin. As a general precaution avoid repeated or prolonged
contact. Remove skin contamination when wet with water. Use proprietary hand
cleaner if the product has dried.

Eye Contact: Although no serious problems are likely to be caused, eyes are
a sensitive area and contact should be avoided. In the event of accidental contact,
irrigate immediately with plenty of clean, cold water and obtain medical attention.

Inhalation: No major hazard; nevertheless use in a well ventilated area. In the
unlikely event of discomfort as a result of inhalation, remove the person to fresh
air.

Oral Ingestion: With proper handling this should not occur. The possibility can
be minimised by not consuming food in the working area and by washing hands
thoroughly before eating, drinking or smoking.

Spillage: Spilt material should be mopped up immediately with an inert,
absorbent material, such as sand, and disposed of in accordance with regulations.

Disposal Of Containers: Do not leave empty containers on site where residue could
be a hazard to children, animals or the environment.

Replace lids and remove any containers to a central disposal point.

Cleaning Of Tools
Clean immediately after use with clean water or white spirit if the material has dried.

Storage
12 months under good storage conditions in original, unopened containers. Keep out
of direct sunlight at a temperature of between 5ºC and 40ºC.
PROTECT FROM FROST.

Container Size
LAYBOND 78 HT is supplied in 15 litre plastic containers.

SPECIFICATION SUMMARY
Type of Solvent Water borne.
Flash Point Non-flammable.
Approximate Specific Gravity 1.25.
Approximate Coverage 45-55m² per 15 litres.
Application Temperature Limits 5 - 40ºC.
Service Temperature Limits Up to 50ºC.

Note: We endevour to ensure that any advice , recomendation or information
we may give in product literature is accurate and correct. However, we have no
control over the circumstances in which our product is used. No responsability
can be accepted or any warranty given by ourselves, our representatives, agents or
distributors, other than that the product supplied by us will meet our written
specification. Products are sold subject to our standard conditions of sale and
each purchaser and end user should at all times ensure that he has consulted our
latest product and safety information sheets.