Why does the old wallcovering need to be removed?
It is usually preferred to remove the existing wallcovering. The moisture content in the paste, as the new wallcovering is drying, may bubble or lift the old wallcovering. In some cases where the wallcovering is very tightly secured and removing it could cause considerable damage to the wall surface, an alternative might be to remove any loose areas to spackle and repair any irregularities, and to use a primer sealer over the existing wallcovering.
