Most billboard posters are printed on a high quality, 120gsm blue backed billboard poster paper that is suitable for paste application.
This heavier than standard weight offers greater tear resistance and easier handling and is blue backed for reduced show through of over pasted posters.
Note: All billboard sites in the UK are privately owned, you must have the permission of the owner before you begin pasting billboard posters.
Use a medium or heavy duty wallpaper paste and read the manufacturer's instructions to find out the amount of water needed. But remember that less is better as you can always add more water if the paste is too thick.
Add the wallpaper powder to clean cold water while stirring with a mixing stick. Add the powder slowly, too much powder at once will make the paste too lumpy and you won't be able to use it. Stir the powder and water until the paste is thick anf leave the paste to sit for about 10 to 20 minutes and then stir again.
You will need to check that you have all the posters and set them out in the order required. You will also need a paint roller with an extension pole to apply the paste. Remember that you will be applying paste over the old poster on the billboard, then rolling the new (unpasted) poster over the top.
If you are using a leaning ladder to access the billboard then read the HSE ladder guide below, make a note of the safety anchor points, which should be used with the correct safety equipment.
If using scaffodling then climb the ladder steps up to the scaffolding with a rope in tow. At the top, drop the rope down to a partner, who will tie the paste bucket to the end. Hoist the paste bucket to the scaffolding. Have your partner hand you the roller with extension pole.
Coat the first third of the old poster with a liberal amount of paste. While you continue to paste, your partner should begin to roll out the new poster over the old poster. Add paste to the edge of the new poster before rolling out. Note that poster panels are printed in such a way that each panel overlaps the next by 25mm approximately.
After the poster is completely applied, roll over the poster edges with another coat of paste to ensure that the edges remain stuck to the billboard surface. The top corners are the most critical, as the weight of the poster can make them curl. Don't worry about wrinkles in the poster, as they tend to lessen as the paste dries.
Before use, first ask yourself: am I fit to work at height? Then think about the condition and the position of the ladder. A leaning ladder in good condition has both feet firmly attached and with a good tread, clean rungs, undamaged stiles (the side pieces that the rungs are attached to) and secure fastenings when it is extended
A leaning ladder in a good position:
Only work on a ladder for a maximum of 15 - 30 minutes at a time. Only carry light materials and tools (up to 10 kg) and always grip the ladder when climbing. Do not overreach - make sure your belt buckle (navel) stays within the stiles and keep both feet on the same rung or step throughout the task. Do not work off the top three rungs - this provides a handhold and try to keep three points of contact with the ladder.
More - HSE Safe Use of Ladders