HP 903 Marmorino

Marmorino

HP 903 is composed of natural hydraulic lime, hydrated white lime, 0.3 mm marble aggregate, marble powders and a small addition of cellulose. HP903 contains no synthetic binders, is highly vapour-permeable (water vapour diffusion resistance factor µ ≤ 7) and, with a pH value of 11–13 (9–11 in the long term), creates conditions unfavourable to mould growth.

Area of application

HP 903 is used for skim coating in interior areas.

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 plaster substrate. The substrate must be sufficiently absorbent, dry, firm and roughened, and free from dust and release agents. Highly absorbent substrates must be pre-wetted, as must all substrates in very warm weather. Protect the freshly applied filler from drying out too quickly. The air and/or surface temperature must be above 5 degrees C. 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 Kalkhaftputz HP 14 lime bonding plaster is recommended. On concrete, apply Kalkhaftputz HP 14 lime bonding plaster first.

Application

Mix the contents of the bucket with clean water. The water requirement is approx. 10 l for 20 kg (1 bucket). Apply HP 903 with the stainless steel trowel. Once it has flashed off (no glossy areas), apply a further coat. After the flash-off time, compact with the Venetian trowel. The surface can be improved further by sanding with 1000-grit wet sanding paper while still damp and then compacting again. The exact working method depends on the substrate conditions and should therefore be determined by preparing sample areas. Protect the fresh skim coat from drying out too quickly.