For all Australian installations, please refer to www.gibbongroup.com.au. It is recommended that tretford roll be installed by sticking directly to the sub-floor or over an underlay.
The subfloor should be dry, sound and level. Using a hygrometer, the relative humidity of the subfloor must NOT exceed 75% – this is a stipulation of the British Standards for Floor Laying Procedures (ref. BS 8230). In Australia, the relative humidity of the subfloor must NOT exceed 70% – this is a stipulation of the Australian standards. Otherwise shrinkage or bubbling can occur and the adhesive bond to the subfloor may be compromised. If installing by direct stick, do not prime or seal the sub-floor. If the subfloor requires levelling, use a sand/cement screed.
At times of extreme humidity changes it is best to unroll the carpet or roll it loosely and allow it to acclimatise for twenty-four hours before installation in the area in which it is to be laid.
CUTTING THE CARPET
tretford’s unique construction allows the carpet to be cut in any direction without fraying. Seams must be double cut when installing bright or non-heathered colours to ensure the cleanest possible join. Seam sealer is not required; however, it may be advisableto seal joins where tretford is cut into designs or where frequent wet cleaning is likely. Seam sealing will limit the ingress of moisture which can undermine the adhesive bondto the subfloor and cause shrinkage. Installers please note that once you have cut the
carpet, you own it! Remember to check colour, quantity, batch and roll sizes against your order before cutting.
DIRECTION OF LAYING
We recommend that rolls be laid with the ribs running perpendicular to the principle light source. Note: tretford’s ribs run across the roll. Tiles should be tessellated i.e. laid checkerboard. Note: Where rolls are laid side by side, the rolls must be laid in the same direction to avoid an illusion of shade variation. This is done by keeping the line marked on the back of each roll always to the same side. On stairs, the ribs may be run parallel or perpendicular to the step.
For permanent bonding, use only rubber/resin-based adhesives: F.Ball’s F3, Mapei Ultrabond Eco 220 (Australia & New Zealand) or Durabond LE9000 (USA). When installing tretford tiles we recommend a peelable/release adhesive such as F.Ball’s F41 or Durabond LE2PR. When installing tretford on walls, we recommend a high tack adhesive such as F.Ball’s F66 or Durabond D7. Note: Spirit based adhesives must never be used when installing tretford. Their use voids all manufacturer warranties.
Direct Stick: Spread Styccobond F3 with the recommended ‘V’ notched trowel (2.4mm x 4.75mm). The coverage rate should be 12-15m 2/5 litres. tretford must be 100% adhered to the subfloor – no spot gluing. Place the carpet and press from the centre outwards to exclude air and ensure overall contact with the adhesive. Roll from end-to-end and side-to-side using a 68kg roller. Roll again after 30 mins.
If installation over an underlay is preferred, a double-stick system must be used with a contract quality underlay (please refer to your local distributor for specific recommendations). The carpet must be 100% adhered to the underlay and the underlay 100% adhered to the subfloor. When applying the Styccobond F3 to the subfloor, use a 1.5mm x 1.5mm trowel. When applying Styccobond F3 to the underlay, use a 2.4mm x 4.75mm ‘V’ notched trowel. Do not use a pressure sensitive/release adhesive at any stage.
In contract situations tretford should always be installed by 100% (all over) direct adhesion to the subfloor using a permanent bond adhesive. If an underlay or pad is required or preferred, a double-stick system and dense, contract grade underlay should be used. 100% adhesion will prevent expansion, contraction and bubbling resulting from changes in humidity. In all dual bond installations, cross-joins must be heatbond taped using dual-bond heat bond tape. In direct stick installations, cross-joins may also be heatbond taped using dual-bond heat bond tape or, if not, must be temporarily tacked in place until the adhesive has permanently bonded so that the joins do not open.
The carpet must never be spot glued.
To avoid problems with shrinkage do not lay tretford into overly wet adhesive. It is important to allow the adhesive to tack-up (dry to a paste like consistency) before lowering the carpet. Tack-up time will depend on atmospheric conditions and on the absorbency of the substrate. The correct tack-up time can be determined by placing a small piece of carpet into the adhesive. When the carpet is pulled away, strings or cobwebs should be apparent. If the correct tack has not developed, wait five minutes, re-check, and re-check every few minutes thereafter until cobwebs appear. Tack-up time can be reduced by double-dropping the carpet into the adhesive. Shrinkage can only occur if there is: – excessive moisture in the subfloor, too high water content in the adhesive, insufficient time is allowed for correct tack to build-up or there are significant changes in air humidity during installation. Shrinkage is not caused by or accepted as a manufacturing fault.
Only cut-in around the perimeter once the adhesive is set.
Please note: adhesive tack-up time will be longer over rubber underlay as it is non-absorbent. When installing over an underlay, to help protect against shrinkage or simply for aesthetic reasons, a 3” wide, flat edge/architectural strip with 3 rows of low profile tacks may also be used around the edge of the room. The carpet is hooked over these, to hold the carpet tight, and tucked-in to give a softer finish to the edges. Cotton head stretchers must be used to avoid tearing or damaging the carpet and seams should be located no closer than 6”-8” from the edge of the room to avoid unsightly peaking.
In residential situations, the carpet may be loose-laid and joined using wide adhesive tape.
UNDER FLOOR HEATING
Both tretford and the recommended adhesives are suitable for use over under floor heating. However, it is recommended that the heating be switched off for 48hrs prior to installation of the carpet and for 48hrs after installation and temperature increased gradually when turned back on.
If possible, lay the cord rather than the roll, perpendicular to the primary light source. Please note, if the cord runs parallel to the light source or if there is very strong overhead lighting, a reflection off the backing may be visible between the ribs until the carpet has settled-in. This is not a manufacturing fault and does not indicate below-standard tuft weight. The phenomenon is only visible when the carpet is newly laid and is not a cause for concern.
tretford cord carpet is a natural fibre product. Different production runs of the same product may therefore be subject to shade variation. This is not a defect or a manufacturing fault.