The Method:

Unroll the underlay, with the printed side up.
Cut to shape leaving excess around the margins.

Fold back one half of the underlay and using a roller apply the Tackifier to the sub-floor ensuring coverage is complete.
Allow the Tackifier to dry completely - it will turn from white to clear.

Unfold the underlay onto the dry Tackifier (if it is not completely dry, the underlay will bond permanently to the sub-floor) and the tackifier will dry very slowly.

Repeat this method with the other half of the underlay. Trim in the underlay neatly around the margins allowing a gap around the area if a tuck finish is required. The gap will depend on the quality and the thickness of the carpet being laid.

All carpet selvedges should be stripped, where necessary, and sealed to prevent fraying. Position the carpet precisely on the underlay before any adhesive is used. All pattern matching, borders and mitred corners should be carefully pre-planned.

The underlay seams should always be laid at right angles to the carpet seams. Fold back one half of the carpet and apply the permanent adhesive with a trowel.

The size of the notch will depend on the backing of the carpet being laid, but it will be a minimum of 1.2mm x 2.5mm. When double-sticking carpets with non-pourous or low absorbant backs (such as action back),

it is important to allow the adhesive to pre-air before the carpet is bonded to the underlay.

The amount of pre-airing time will depend upon local conditions. It is not advisable to lay this type of carpet straight into web adhesive.

Corners of the trowel should be rounded with a file to prevent them catching on the underlay top surface. Unfold the carpet onto the permanent adhesive and use the glider to smooth out any wrinkles or bubbles and to ensure a firm bond. Repeat this method for the other half.

All seams should be bonded with F30 seaming cement.
Carefully trim in the carpet in the preferred manner.