HP 90 Natural Lime - fine colored plaster, white

Lime decorative plaster, white

HP 90 is a decorative finishing plaster. Please note for exterior use: HP 90 is not water-repellent. HP 90 is available in natural white, white and tinted colours.

HP 90 is composed of natural hydraulic lime, hydrated white lime, marble powder, marble aggregate and a small addition of cellulose. HP 90 contains no synthetic binders, is highly vapour-permeable (water vapour diffusion resistance factor µ ≤ 7), and its pH value of 11–13 (9–11 in the long term) creates conditions unfavourable for mould growth. HP 90 is produced in grain sizes of 0.3mm, 0.5mm and 1mm.

Substrate: 

The ideal substrate is a lime plaster (e.g. HP 9 or HP 9L) or a lime-cement plaster HP 1. DIN 18350 and 18550 must be observed when assessing and preparing the substrate. The substrate must be sufficiently absorbent, dry, firm and keyed, and free from dust and release agents. Priming with Hessler Silikatgrund is recommended. Experienced users can also prepare the substrate by pre-wetting it with water. The air and/or surface temperature must be above 5 degrees Celsius. Pure lime mortars must be kept free from frost for four weeks. Substrates unsuitable for pure lime plasters (e.g. gypsum plasters) must be sealed with Hessler-Putzhaftgrund, and plasterboard/gypsum boards with Hessler Iso-Grund. On board substrates, a mesh-reinforced skim coat with lime bonding plaster HP 14 is recommended.

Application

Mix the contents of the sack with clean water. The water requirement is approx. 7 l for 20 kg (1 bucket). First apply HP 90 in one layer with the trowel. Once it has flashed off, apply a second layer and, when it has started to set, rub it down with the sponge float (fine texture). Protect fresh plaster from drying out too quickly; if necessary, mist it with water after application. The lime casein paint (HP 9000) is particularly suitable for a subsequent coat of paint.