MARMOBACK-COAT

MARMOBACK-COAT is a cutting-edge hybrid, flexible, single-component resin with a mineral binder designed specifically for back coating marble and natural stone slabs. This formulation provides exceptional sub-surface protection against capillary moisture rise, dampness, and mineral stains (such as efflorescence and rust marks) without compromising the bond strength of the stone with cementitious or epoxy tile adhesives. Unlike conventional hydrophobic sealers which create bond-breaking silane/siloxane barrier films, MARMOBACK-COAT features mineral active binders that chemically and mechanically bridge the marble back with adhesive mortars (tested to maintain full bond strength with C2 adhesives under EN 12004).

Key Highlights

• Superior moisture protection: blocks rising dampness, substrate humidity, and moisture migration, supporting the longevity and structural stability of installed marble.
• Mineral stain and efflorescence resistance: prevents moisture-borne salt leaching, yellowing, water stains, and alkaline mineral stains without altering the appearance of the stone face.
• Preserved bond strength: unlike traditional silicone or hydrophobic sealers that reduce adhesive grip, MARMOBACK-COAT maintains full bond strength with tile and stone adhesives (C2 standard compliant).
• High flexibility and crack bridging: elongation at break exceeding 100%, accommodating thermal movement, substrate shrinkage, and vibration without cracking or delamination.
• Ready-to-use: single-component viscous liquid requiring no on-site mixing, induction time, or dilution.
• High UV resistance: suitable for interior floors and walls as well as external cladding and facade installations.

Technical Specifications

Parameter	Specification
Product name	MARMOBACK-COAT
Chemical composition	Hybrid resin with mineral binder
Physical appearance	Viscous liquid
Colour	White or transparent (customizable upon request)
Specific gravity	~1.35 – 1.45 g/cm³
Dry film thickness (DFT)	1–3 mm (depending on substrate)
Elongation at break	> 100% (high flexibility)
Water resistance	Excellent water repellency (tested up to 48 hours continuous exposure)
Adhesive bond compatibility	Full bond strength retention with C2 adhesive (EN 12004)
UV resistance	High resistance to UV degradation
Touch dry	2–4 hours (ambient dependent)
Full cure	Up to 24 hours (before installation/fixing)
Standard pack	10 kg container
Shelf life	12 months in unopened original packaging under dry conditions
Storage	5°C to 35°C (protect from direct sunlight and frost)

Application & Handling

1. Surface preparation. Inspect the backside of the marble or natural stone slab. It must be structurally sound, clean, dry, and free of dust, cutting slurry, grease, waxes, or cutting oils. Remove loose fiberglass mesh, deteriorated resin backings, or unstable netting before applying MARMOBACK-COAT. The slab must be dry internally, not merely surface-dry.

2. Mixing & preparation. MARMOBACK-COAT is a single-component, ready-to-use system. No dilution or mixing with water, thinners, or solvents is required or permitted. Stir briefly if stored for an extended period to ensure homogeneous consistency.

3. Application. Apply evenly using a brush, roller, or suitable spray gun directly onto the reverse side of the marble slab. Ensure 100% continuous coverage, with particular attention to edge sealing to prevent capillary moisture migration along slab perimeters. Achieve a uniform dry film thickness of 1–3 mm.

4. Drying and curing. Allow the coated marble to dry for a minimum of 2–4 hours under ambient conditions before moving or handling. If a second coat is specified for extremely porous stone or high-risk wet installations, apply once the first coat is dry to the touch. Allow up to 24 hours for full chemical cure before setting the marble with adhesive mortars.

Do’s

• Ensure the backside of the stone is completely dry, clean, and free of slurry or loose backing mesh.
• Apply a uniform coating of 1–3 mm dry film thickness.
• Seal all exposed slab edges to prevent perimeter moisture infiltration.
• Allow at least 4 hours before handling and up to 24 hours of curing before tile adhesive fixing.
• Verify that the stone is fully dry before starting installation.

Don’ts

• Do not apply on wet, damp, or moisture-saturated stone slabs.
• Do not exceed recommended film thickness, as excessive thickness may impair adhesive bed leveling.
• Do not fix marble onto the substrate before the coating has completely cured (allow 24 hours).
• Do not dilute or mix MARMOBACK-COAT with water, solvents, or additives.
• Do not trap moisture between the coated stone and the concrete substrate during installation.

Storage & Safety

Storage: Store in a dry, cool location between 5°C and 35°C in tightly sealed original containers. Protect from frost and direct solar radiation.

Handling: Wear protective nitrile gloves, protective eyewear, and appropriate workwear. Maintain adequate ventilation during application.

First aid:

• Inhalation — move to fresh air promptly; seek medical attention if breathing is difficult.
• Skin — wash thoroughly with soap and water.
• Eyes — flush immediately with clean water and seek medical attention if irritation persists.
• Disposal — dispose of container and product residue in compliance with regional environmental statutes.

Frequently Asked Questions

What is MARMOBACK-COAT?
A flexible, single-component hybrid resin with mineral binders formulated specifically for back coating marble and natural stone slabs to prevent water ingress and staining.

Why is back coating necessary?
Natural marble is porous and prone to absorbing moisture, cement alkalis, and minerals from wet screeds or adhesives, causing dark damp spots, efflorescence, and yellow staining. Back coating forms an impermeable moisture barrier.

How does it differ from conventional hydrophobic sealers?
Traditional silane/siloxane hydrophobic sealers create a slick, water-repelling boundary that can destroy the adhesive bond of tile mortars. MARMOBACK-COAT contains active mineral binders that preserve full bond strength with cementitious and epoxy adhesives.

Which adhesives are compatible?
C2-grade cementitious tile adhesives (tested under EN 12004) as well as epoxy- and polyurethane-based stone adhesives.

Does it need to be mixed with water or hardener?
No. It is a single-component, ready-to-use formulation. Do not dilute with water or chemical thinners.

What is the recommended application thickness?
Dry film thickness of 1–3 mm, depending on stone porosity and site requirements.

How is it applied?
With a standard paintbrush, paint roller, or airless spray gun.

How long does it take to dry?
Touch dry in 2–4 hours depending on ambient temperature and humidity, and 24 hours for full cure before installation.

Can it accommodate substrate movement?
Yes. Elongation at break exceeding 100% bridges micro-cracks and absorbs thermal/structural shifts without rupturing.

What is the water resistance performance?
Outstanding water barrier performance, tested for up to 48 hours of continuous water exposure without moisture transmission.

Should existing fiber mesh be removed before coating?
Loose, detached, or unstable mesh must be stripped away. Well-adhered structural mesh can be coated directly if it is clean and free of oily residues.

Can a second coat be applied?
Yes. On highly porous stone or heavy moisture areas, apply a second coat once the first coat is dry to the touch.

What colours are available?
White or transparent as standard; custom shades can be formulated upon request.

What is the pack size?
10 kg containers.

What is the shelf life and storage?
12 months from manufacture when stored unopened in dry conditions between 5°C and 35°C, protected from frost and direct sunlight.

Can it be applied to wet or damp marble?
No. The backside of the stone must be completely clean and dry to ensure optimum chemical adhesion.

Is it suitable for outdoor facades and cladding?
Yes. High UV resistance and a flexible mineral-resin matrix make it suitable for exterior facades, external stone cladding, and balconies.

Why is edge coverage important?
Coating slightly around slab edges prevents lateral capillary suction of water and salts along the perimeter joints of installed tiles.

What PPE is needed?
Protective gloves, safety glasses, and application in well-ventilated spaces.