08 — DALGA BAU · Hamburg · since 2000
Renovation plaster in Hamburg – for damp and salt-laden walls
Damp basement walls, salt efflorescence, spalling render on the plinth: renovation plaster stores salts and keeps the plaster surface dry – it does not, however, remove the cause of the damp. DALGA BAU applies renovation plaster systems inside and out – in older buildings, basements and plinth zones.
When renovation plaster makes sense
- White salt efflorescence and damp marks on walls
- Crumbling or spalling plaster in plinth and basement areas
- Moisture-affected masonry in older buildings, e.g. after retrofitted waterproofing
- Historic and listed buildings – after assessing masonry and salt load, in consultation with heritage authorities where needed
How renovation plaster works
Renovation plaster is highly porous yet water-repellent. Salts from the masonry are stored in its pores while moisture evaporates as vapour. The surface stays dry and largely free of efflorescence – how long depends on the ongoing supply of moisture and salts in the masonry.
Important: renovation plaster does not replace waterproofing. The cause of the damp – such as a missing damp-proof course – is investigated first; necessary waterproofing or drying measures are carried out beforehand or alongside.
Process
- Assess the substrate – determine moisture and salt load
- Remove old plaster – well beyond the damaged zone, rake out joints, clean the masonry
- Spatter coat and base coat – with a porous base coat where salt load is high
- Renovation plaster applied at the specified thickness
- Breathable finish – e.g. mineral finishing render or silicate paint
The system build-up follows the manufacturer’s specification and the WTA guideline for renovation plaster systems.
Inside and outside
Inside, we mainly use renovation plaster in basements and ground floors of older buildings – more on plaster types under interior plastering. Outside, it is used on damp facades and plinths – always together with plinth waterproofing and splash protection, see exterior render. On request we also apply the final paint finish.
Frequently asked questions
Does renovation plaster replace waterproofing?
No. Renovation plaster stores salts and keeps the surface dry, but it does not stop water from penetrating. If there is no damp-proof course or water presses in from outside, waterproofing comes first – then the renovation plaster.
When can renovation plaster be painted?
Only after sufficient hardening and drying as specified by the system manufacturer – thickness, temperature and humidity all play a role. Only breathable paints are used, e.g. silicate paint.