Stone & Composite Coating — Maintenance Guide
Practical methods for keeping exterior stone and composite surfaces long-lasting with joint renewal, correct cleaning and protective applications. Related service page: Stone & Composite.
Introduction
Exterior natural stone (travertine, marble, basalt, etc.) and composite (HPL, fiber cement, composite panel) coatings are in constant contact with climate, dirt and UV. With correct cleaning chemistry, solid joints and breathable protectors, surface life is significantly extended.
Cleaning & Stain Removal
- pH compatibility: Acidic products are not used on calcite-containing stones (marble/travertine). Neutral/alkaline cleaners are preferred.
- Rust/run stain: For iron-containing stains, acid-free chelator-based products or poultice (drawing paste) application.
- Oil stain: Solvent + poultice on absorbent stone; microfiber and suitable detergent sufficient on composite.
- Salt efflorescence: Low-pressure water, then manufacturer-approved efflorescence remover and good rinsing.
- Test area: Each chemical should first be tested on a 30×30 cm test area.
Joint Renewal & Repair
- Removal: Loose/cracked joints are scraped to 3–5 mm depth, cleaned from dust.
- Material: Exterior, polymer-reinforced, low water absorption joint mortar; mastic at movement points.
- Expansion joints: Backer rod + UV-resistant neutral silicone/polysulfide at 4–6 mm gap.
- Curing: Avoid water load for min. 24–48 hours after application.
Protective Applications (Sealer/Impregnator)
- Silane/siloxane impregnation: Water-repellent, breathable protection; doesn't change appearance (natural look).
- Wet-look (wet-look) varnishes: Gives texture depth on stones like travertine/basalt; choose products with high UV stability.
- Composite panel: Manufacturer-approved antistatic/UV topcoat; local renewal possible on scratches.
- Application: 2 coats wet-on-wet on dry surface; in shade, windless environment.
Moss-Mold & Rain Marks
- Biocide: Structure-compatible, chlorine-free biocide applied; 10–15 min wait + thorough rinsing with water.
- Drainage: Clogging of gutters and drip edges should be removed; water marks usually result from flow errors.
- Shaded/humid facade: Periodic frequency increased, permanent darkening on surface prevented.
Pressure Washing: Risks & Settings
- Pressure: 80–120 bar range is sufficient; don't direct at joints and edges.
- Distance: Keep gun 30–40 cm away from surface; use fan tip.
- Sequence: Pre-wetting → cleaner → soft brush → rinsing. Hot water according to manufacturer for composite.
Periodic Maintenance & Budget
| Item | Period | Description | Range (₺/m²) |
|---|---|---|---|
| General cleaning | 6–12 months | Washing with pH neutral/suitable chemistry | … |
| Joint renewal | 3–5 years | Polymer-reinforced joint + mastic | … |
| Water-repellent impregnation | 2–4 years | Silane/siloxane 2 coats | … |
For exact price, we do on-site inspection according to surface type, height (scaffolding), m² and access.
Frequently Asked Questions
Yellowing on marble/travertine, how to remove?
Local application with acid-free chelator + poultice, then neutralization and water-repellent impregnation.
Why are joints cracking?
Omission of movement joints, UV and water load or wrong mortar selection. Solution: open expansion joint, polymer-added mortar and suitable mastic.
Does pressure washing damage the surface?
High pressure can erode joints. Safe work with 80–120 bar range, 30–40 cm distance and fan tip; test area first.
Call to Action
Let's identify surface type on site and open a test area; cleaning + impregnation in one day!