Where, because of too light construction, ballasting is not possible, or for roofs with light slope (up to 10°), bonding may be the right solution.

Spread the sheet out over the roof area as described above.

Roll back on half of the sheet to the centre of the roof.

Using a can of P150 adhesive, punch approximately six nail holes in the bottom of one side of the can and release the lid.
 The adhesive can now be poured in narrow parallel beads from the nail holes onto the roof.

Apply adhesive over an area approximately 1 - 2 meters ahead of the rolled back Prelasti. 
Allow some time, usually 5 – 10 minutes, before proceeding to allow the solvent vapour in the adhesive to dissipate away. 
The period to allow will depend on the weather conditions at the time of the laying.

Un-roll the Prelasti membrane by kneeling on the sheet and pushing the roll onto the adhesive, maintaining tension on the sheet during the process.

Using the sweeping brushes, brush the membrane immediately while the adhesive is still liquid to remove creases and bubbles. These should be brushed to the sheet edges. While the adhesive is still wet, the membrane may be worked in to place by brush and by hand.

Depending on the weather conditions at the time of laying, some blisters may remain under the sheet. The majority of these will disappear over time as the solvent vapours dissipate under and through the membrane.

If there are penetrations on the roof which have not been incorporated into the sheet at the prefabrication stage, these should be cut out of the membrane as the roll arrives at each one during the bonding process. This is accomplished by rolling the membrane up to the base of the object and then loosening off enough material to fold back and lay flat away from the base. The measurements of the object base can then be transferred on to the membrane using chalk and the correct shape cut out of the sheet. Pull the sheet over the object and proceed with bonding as described above.

Seal all perimeters, outlets and upstands as described in the “Detailing” proceedings that may vary from country to country.