Old walls tell a story. Whether stone, brick, cob or plaster, they have heritage value... but also specific constraints.
To respect their singularity while providing comfort and performance, more and more professionals are opting for ecological wall coverings, based on bio-sourced and mineral components.
But the application of an eco-responsible rendering on an old support cannot be improvised. It requires a rigorous methodology and precise technical choices.
🧩 Step 1: accurately diagnose the substrate
First of all, you need to know the substrate:
- Type: stone, brick, concrete, cob, old plaster...
- Condition: cracks, damp, chalking, saltpetre...
- Old coating: plastic paint, cement coating, wallpaper...
🎯 The aim is to assess possible adhesion, necessary breathability and any treatments required.
🧽 Step 2: gentle cleaning
The substrate must be clean, sound and consistent:
- Thorough dusting
- Removal of loose parts
- Possible stripping of waterproof paint (not compatible)
- Clean with clear water or white vinegar if mould is present
❌ Avoid aggressive or chemical products, incompatible with an eco-responsible approach.
🧱 Step 3: correct major irregularities
Old walls often show :
- Holes or cavities to be filled
- Active or passive cracks to be treated
- Lack of flatness
It is essential to :
- Fill with a compatible mortar (preferably lime-based)
- Stabilize cracks (fiber reinforcement or bridging if necessary)
- Keeping the wall breathable
💡 A biosourced coating, like Absolin, adapts perfectly to irregularities, but a well-prepared substrate guarantees the final quality.
🌱 Step 4: controlled humidification
Before plastering :
- Lightly dampen the wall (especially if it is very porous).
- Avoid surfaces that are too dry or too hot, which will absorb water too quickly.
- Maintain a balance: neither wet nor dry
🎯 This helps the biosourced rendering to grip and set evenly.
🛠️ Step 5: Apply eco-friendly plaster in appropriate coats
Depending on the product chosen (such as Absolin), application is :
- Apply a thin or medium coat, depending on the desired finish
- With appropriate tools: stainless steel float, smoothing tool, float
- Respecting setting and drying times (without accelerants)
✅ A good product enables smooth, odorless application and cleaning of tools with water.
🎨 Step 6: Finishing and customizing
Once the plaster has been applied :
- You can leave it raw, shoe it, or structure it.
- Decorative effects can be achieved: brushed, shaded, floated, etc.
- A natural protective treatment (e.g. black soap, vegetable wax) can be applied depending on use.
📌 The aim: to combine aesthetics and sustainability, without betraying the spirit of the place.
✅ Focus on Absolin: an ally for responsible renovations
Absolin plaster, made from linen, lime and marble powder:
- Ideal for old substrates thanks to its flexibility
- Respects the breathability of walls
- Generates no toxic emissions
- Offers ease of installation, mineral aesthetics and sustainable performance
It's an eco-responsible renovation solution perfectly suited to heritage projects.
🧠 Summary: the right reflexes to adopt
Step | Objective |
Diagnosis | Know the nature and condition of the wall |
Cleaning | Removing obstacles to grip |
Correction | Preparing a healthy, stable base |
Humidification | Promote plaster setting |
Application | Lay in harmony with the substrate |
Finish | Enhancing the value of the work and protecting the wall |
Renovating an old wall with an ecological wall covering is not a constraint: it's an opportunity. It's an opportunity to enhance the value of existing buildings, provide thermal and acoustic comfort, and preserve indoor air quality.
💡 By following these steps and choosing a quality biosourced rendering, professionals commit to a responsible approach, without compromising on aesthetics or durability.