Plastering - "Chicken Wire" Cracking in new finish

[Rocky62]

An old wall has had a new plastering finishing coat of about 2-3mm applied over an old wall.

The new coat has widespread random patches of 'chicken wire' cracking. The pattern resembles hexagonal chicken wire, like small hairline hexagons. The cracks are mostly full depth of the new skim coat. This plaster is loose and sounds hollow when tapped.

It was applied to a wall that had had the wall paper steamed off in the morning. The original plaster had a painted finish, but some of the paint was removed with the wallpaper removal.

Weather outside 1 deg C. Plaster applied to an internal leaf of a cavity wall to the gable of the property. The central heating was turned off for the installation but ambient heat of the house kept the room from being too cold.

Any ideas why the plaster has failed like this?

Many thanks

Pierre

 

[roughcaster]

Sounds to me like the whole skim coat has blown. You describe it as chicken wire effect, but it is also called spider web, crack lines radiating from the centre. If it is loose and sounds hollow, you'll have no problem taking it off, because that's the only solution, then you can start again,,, properly. The prepartion of this wall before plastering it, sounds non existent. Wallpaper stripped off and then plastered, no prep ,,,,was it really like that? and who dun it??????

Roughcaster.