Plaster - Frequently asked questions
No. Limelite plasters can be applied using standard plastering tools and techniques. Simply follow the instructions provided on the bag. Care should be taken not to ‘polish up’ the finished surface as this can reduce breathability.
Limelite Plasters should be applied between 5-30°C.
Limelite Renovating Plaster can be applied between 7-15mm thick. Where a thickness of over 15mm is required, the plaster can be built up over several layers leaving at least 24 hours drying time between each layer.
The final floating coat must be scratched with a devil float and left for a minimum of 24 hours before applying Limelite High Impact Finish to a thickness of 2-5mm.
Preparation of Substrates
Chalk walls must first be covered with expanded metal lathing (EML). The lath can be fixed with masonry nails or screws, but not gypsum plaster.
Limelite Renovating Plaster can be applied over cementitious tanking systems, but not bitumen or pitch. Note – compatibility tests have not taken place so we cannot guarantee product performance.
Areas around a chimney breast are likely to be impregnated with soot containing salts. We recommend a thick stipple coat of Easy Bond is applied to the area prior to plastering.
Any paint must be removed or covered with EML before being plastered, as this can affect the strength of the bond between the plaster and the substrate.
All traces of Gypsum should be removed from the substrate before plastering commences. Gypsum plasters are hydroscopic and absorb moisture. Over time this moisture causes the gypsum to disintegrate and hollow spots will appear in the wall where plaster has deteriorated. If the substrate is of a loose, friable nature this needs to be stabilised before plastering is carried out.
Yes, Limelite Easy Bond should be used to prime the wall, followed by the initial coat of Limelite Renovating Plaster once the primer is tacky.
You cannot use PVA with any Limelite product. PVA tends to re-emulsify when damp which will affect the bond of the material to the substrate. SBR will act as a water proofer and negate the performance of Limelite Renovating Plaster. The only primer/bonding agent we would recommend for use is Limelite Easy Bond as it is breathable.
Gypsum plaster and plasterboard is not breathable, and therefore the benefits of High Impact Finish will be negated when used over gypsum backgrounds. Limelite High Impact Finish should only be used over plasterboard as a decorative coating; for example, a partition wall that needs to match an external wall. Limelite Renovating Plaster or Whitewall One Coat cannot be applied to plasterboard.
It is possible for Limelite Renovating Plaster and High Impact Finish to be used in the same project as gypsum based materials, however note that the use of gypsum over Limelite plasters will nullify its breathability. High Impact Finishing Plaster used over Gypsum backgrounds will not be breathable or flexible and should be considered decorative only.
No. Since Limelite is a breathable material, any moisture retained in the wall should be releases over time, provided that a breathable finish is also used. This means that Limeilite products are ideal for repairs on flood damaged properties.
Preparation of Substrates
Any paint used must be breathable. Typically, these are water based, trade emulsion or clay/mineral based paints. Avoid vinyl paints.
Limelite dries from front to back, so once the visible surface is ‘white dry’ it will be ready to receive paint. Typically this is around 24 hours after application. We recommend that a few thin coats of watered down emulsion are used rather than one thick layer.
Wallpaper is generally not recommended for use with Limelite as many wall papers are non porous. Wallpaper is not suitable unless the cause of the damp is rectified and the wall is fully dry, otherwise it will trap moisture.
No Limelite plasters are designed for use on internal walls only.