Can the cement board plaster directly?
Equal to 20mm can be set in the wall waterproofing mortar waterproof, if more than 20mm can be set in the decoration of the wall in the plaster, the plaster is usually set in the decoration of the wall of the plaster
Shelf life is a number, that is, in most cases, some product deterioration time, is not absolute. Some foods are still well preserved for a long time. Some food is not saved until the shelf life is broken. So depending on the specific circumstances, if your cement is good, expired but no deterioration, it can be used, if the metamorphic,
No, the mortar of the cement mortar mainly look inside and outside the plastering practice is the same, you can see the table, mortar thick, what type, at a glance. External cement mortar is generally waterproof mortar, if the mortar surface thickness is small
