F_BALL_SUBFLOOR_PREP_BROCHURE-Jan-26 - Flipbook - Page 18
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Subfloor Preparation Guide | All aspects of subfloor preparation and floor covering installation
WOODEN
FLOORS
All wooden floors must be structurally sound, level, smooth, dry and
clean. Adequate ventilation should be provided to suspended timber
floors at ground level to ensure that the moisture content of the wood
is maintained at equilibrium.
Worn or uneven floorboards should either be
replaced or levelled by sanding, planing or by
patch filling with Stopgap Green Bag/114 Liquid,
Stopgap 1200 or Stopgap 1500 floor smoothing
compound, before finally covering with plywood
conforming to BE EN 636 Class 2 (Suitable for use
in humid conditions) and should be constructed with
hardwood veneer and EN314-2 Class 3 (exterior)
for the glue bond.
The sheets should be fixed using screws in a line
12mm in from the sheet edge at 100mm centres
and at 150mm intervals at intermediate centres
across the sheets and all joints should be staggered.
Wood blocks laid on ground floors must have an
effective damp proof membrane incorporated in
the concrete subfloor. They may be overlaid with
a suitable grade of plywood (secured with screw
fixings and either Stycco Flex, Styccobond B95 or
as described above). However, it must be ensured
that the wood blocks are well bonded and remain
fully secured to the subfloor and that the plywood
overlay and wood blocks remain dry during the life
of the installation.
If these conditions can not be met, then the wood
blocks must be removed and the subfloor made
good with either a flooring grade asphalt (complying
with BS 8204-5) or a modified sand/cement
screed incorporating an effective damp proof
membrane. Alternatively, apply Stopgap F77 WSM,
Stopgap P141 Primer, Stopgap 600, Stopgap P131
and Stopgap 300 smoothing compound.
Wood blocks are not suitable for direct application
of sheet or tile flooring because of the continuous
differential movement of the blocks and the risk of
the wood block design showing through the floor
covering surface.
Wooden floorboards (including butt jointed and
tongue and groove boards) must be overlaid with
a minimum of 6mm plywood overlay, screw fixed
at the centres outlined above to provide a rigid,
deflection free, substrate. They may then be
primed using dilute Stopgap P131 Primer and
Stopgap 700 applied at minimum thickness of
2mm and a maximum thickness of 10mm applied.
