Description
LAYBOND 77 is a white, non-staining acrylic dispersion adhesive specially
formulated to produce a high degree of tack in its dry film. It has excellent bond
strength and resistance to plasticiser migration.

Uses
LAYBOND 77 is used to bond PVC floorcoverings to concrete, cementitious
screeds, chipboard, hardboard, plywood and smoothing compounds. With care it
can be used on non-porous surfaces, such as asphalt, although it is always
advisable to apply a minimum 3mm application of LAYBOND SCREEDMASTER
2 LATEX SMOOTHING COMPOUND. LAYBOND 77 is also suitable for bonding
some types of heavy duty wall coverings.

LAYBOND 77 is suitable for use where there is 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 latest editions of the following
standards:-

BS CP102 Code of Practice for protection of buildings against water from the
ground.

BS 8203 Code of Practice for installation of sheet and tile flooring.

Sub-floor

The sub-floor should be clean, structurally sound, dry and free from any
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 less than 75% RH. Where this has
not been achieved the use of 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 sheets 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.

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 77 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 floorcovering manufacturer. The adhesive should
be spread with a sweeping motion at a 60º angle and an open time of
approximately 15 minutes allowed prior to placing floorcovering. Even pressure
should be applied to ensure good overall contact.

Non-porous surfaces

When laying onto non-porous or low porosity surfaces eg. asphalt, LAYBOND
SCREEDMASTER 2 LATEX SMOOTHING COMPOUND should normally be
applied to a depth of 3mm and allowed to dry overnight. Application can then
proceed as for porous surfaces. However, where circumstances preclude this
treatment either of the following methods should be used:-

either:

i) Lay the floorcovering into wet adhesive and apply pressure to obtain good
contact. Pull back immediately and allow the adhesive to reach a touch tacky
state, or


ii) Allow the adhesive on the floor to reach a touch tacky state, then place the
floorcovering and press firmly overall to obtain contact.

Finishing
It is essential to ensure good overall contact between the floorcovering and the
adhesive. This may be achieved by use of a 68Kg WOLFF roller or other method
recommended by the floorcovering manufacturer.

Safe Handling Precautions
Flammability: Non-flammable.

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 cold clean 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 water or white spirit if the material has dried.

Cleaning Of Surface
Any LAYBOND 77 on the surface of the floorcovering should be removed
immediately with a damp cloth.

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 Sizes
LAYBOND 77 is supplied in 15 and 5 litre plastic containers.

SPECIFICATION SUMMARY
Type of Solvent Water borne, containing some aromatic solvent.
Flash Point Non-flammable.
Approximate Specific Gravity 1.2
Approximate Coverage 45-55m² per 15 litres.
Application Temperature Limits 5ºC- 30ºC.
Service Temperature Limits Up to 40ºC.

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.