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Concrete/Sand Cement Screeds (New)
For new concrete floors below 75%RH,
i.e. dry. Clean the floor to remove
contamination (laitance, paint, plaster,
etc). Prime the floor and then apply a
compatible smoothing compound to a
minimum of 3mm. For readings above
75%RH consult your supplier for
information relating to surface DPM
requirements.
Concrete/Sand Cement Screeds
(Old/Refurbishment)
With readings below 75%RH, old floor
covering and adhesive residues must be
removed and the surface primed before
applying a compatible smoothing
compound to a minimum of 3mm. For
readings above 75%RH consult your
supplier for information relating to surface
DPM requirements.
Power Floated Concrete
If readings with the hygrometer are below
75%RH the power floated floors require
abrasion prior to the application of a
primer and compatible smoothing
compound to a minimum of 3mm
(abrasion can be either scarification or
light shot blasting). For readings above
75%RH the surface still require abrasion
before applying a surface DPM.
Quarry Tile/Mosaic/Terrazzo/Ceramics
Test floor for evidence of damp. If after
testing, dampness is apparent consult your
supplier. Check floor area for unstable,
loose or broken tiles. Remove loose
pieces and fill deep holes with rapid drying
mortar. Degrease, rinse and abrade the
surface of the floor. Apply primer and
compatible smoothing compound to a
minimum of 3mm. A second top coat of
primer and smoothing compound may be
required to nullify sinking of smoothing
compound over old tile grout lines.
Asphalt
Asphalt should be de-greased and
the surface rinsed with clear water.
The surface should then be primed
and a compatible smoothing compound
applied to a minimum of 4mm.
Timber Floors
Standard Floorboards/Tongue and Groove
Floorboards should be well secured, loose
boards firmly fastened, worn/broken
boards replaced. Lay a minimum of 6mm
flooring grade plywood, fixed at maximum
150mm centers. Then apply a full coat of
skim coat over the plywood.
Undulating Timber Floors
Alternatively for undulating timber floors
apply a primer over the plywood and a
minimum of 3mm coat of fibre reinforced
smoothing compound.
All Chipboard/MDF/Weyrock
Overlay with a 6mm flooring grade
plywood fixed at maximum 150mm centers
and apply full coat of skim coat.
Wood Mosaic Panel/Woodblock/
Wood strip
Remove any of these products if laid direct
to earth/bitumen/pitch, these should not
be overlaid with an impervious vinyl. If laid
onto a wood floor, check to ensure all
flooring is securely fitted then treat as
timber floors.
Flooring Grade Plywood Floors
Apply full coat of skim coat to smooth
joints and fixings in plywood. Alternatively
apply primer and lay minimum of 3mm
coat of fibre reinforced smoothing
compound. Any plywood floors with
thickness less than 6mm treat as
chipboard.