Fireproof MGO Board For Roof

As a core carrier of sustainable buildings, green roofs must simultaneously meet five key requirements: structural load-bearing capacity, waterproofing and anti-seepage, fire safety, root penetration resistance, and environmental friendliness. Fireproof MGO Board (Class A1 non-combustible magnesium oxide board), with customized modification technology, has become a "multi-functional core layer material" for green roof systems. It not only addresses pain points of traditional green roofs such as weak fire resistance, excessive load, and water leakage caused by root penetration but also adapts to plant growth and ecological sustainability through its environmental properties. Below is a detailed analysis of its applications in green roofs:

 

Positioning and Customized Characteristics of Fireproof MGO Board for Green Roofs

Fireproof MGO Board for green roofs is not a simple reuse of general-purpose MGO boards but a specialized material modified for the unique environment of green roofs (soil + plants + irrigation). It is positioned as an integrated solution for "structural load-bearing layer + fire barrier layer + root-resistant waterproof base layer" with three core modifications:

1. Customized Modification Upgrades (Adapting to Green Roof Requirements)

Root Penetration Resistance Modification: Surfaces are compounded with a 1.2mm thick HDPE root barrier membrane (or added with copper ion root inhibitors), passing the FLL Green Roof Standard root resistance test to prevent plant roots from penetrating the board and damaging the structure and waterproof system.

Super Waterproof Enhancement: Adopts vacuum compression molding technology with a porosity ≤2%, and the surface is sprayed with a nano-silane waterproof coating. The water absorption rate is ≤4% (far lower than 10-15% of traditional materials), with no softening or water seepage after 72 hours of immersion.

Lightweight and High-Strength Optimization: Density is controlled at 900-1050kg/m³, 60% lighter than concrete boards and 30% lighter than fiber cement boards, meeting load-bearing requirements while reducing roof structural load.

Environmentally Friendly and Non-Toxic Modification: Uses a chlorine-free formula (magnesium sulfate curing system), with zero formaldehyde and heavy metal emissions, and a neutral pH value (7.0-7.5). It does not pollute soil or plant roots, complying with EU REACH and US EPA environmental standards.

 

2. Core Technical Parameters (Green Roof-Specific Standards)

Performance Indicator	Technical Parameters	Significance for Green Roof Adaptation
Fire Rating	EN 13501-1 Class A1 (Non-combustible)	Blocks roof fire spread, meeting fire safety codes for public buildings
Root Penetration Resistance	FLL Green Roof Standard Class R1	Prevents plant roots from damaging the board and waterproof system
Density	900-1050 kg/m³	Reduces total roof load (soil + plants + board)
Compressive Strength	≥25 MPa	Bears the weight of soil (150-200kg/㎡) + plants
Water Absorption Rate	≤4% (ASTM D1037)	Avoids board softening due to water absorption and prevents water penetration into the interior
Service Life	≥60 years (verified by accelerated aging tests)	Matches the 30-50 year design life of green roofs
Environmental Certification	LEED/BREEAM Certification Compatible	Helps buildings gain points for green ratings

 

Core Application Functions of Fireproof MGO Board in Green Roofs

The typical structure of a green roof (from bottom to top) is: Roof Structure Layer → Insulation Layer → Fire Barrier Layer → Waterproof Layer → Root Penetration Resistance Layer → Drainage Layer → Filter Layer → Growing Medium Layer. Fireproof MGO Board can integrate three functions: "fire barrier layer + root penetration resistance layer + waterproof base layer" and can also serve as a drainage guide layer in some scenarios, simplifying the construction process:

 

1. Core Function 1: Fire Barrier Layer (Safety Bottom Line of Green Roofs)

Application Pain Point: Soil, plants, and wooden drainage layers of traditional green roofs are flammable/combustible materials. In case of fire, the fire easily spreads from the roof to the building interior. Especially for public buildings (such as shopping malls, hospitals, and schools), there are mandatory requirements for roof fire safety.

MGO Board Solution: Class A1 non-combustible property ensures no combustion or open flames at 800℃ and structural stability at 1200℃, forming a continuous fire barrier to prevent fire from penetrating from the roof to the interior or spreading between buildings.

Key Advantage: Compared with traditional fireproof coatings (prone to aging and requiring regular renovation), MGO Board is a permanent fireproof structural layer with the same service life as the green roof, requiring no later maintenance.

 

2. Core Function 2: Root Penetration Resistance + Waterproof Base Layer (Core of Green Roof Leakage Prevention)

Application Pain Point: Plant roots (such as sedums and shrubs) in green roofs have strong penetration power, which can easily damage traditional waterproof membranes (such as PVC and TPO) and cause water leakage. At the same time, long-term immersion in irrigation water and rainwater can easily cause softening and mold growth of base materials.

MGO Board Solution:

Root Penetration Resistance: The composite HDPE root barrier membrane or copper ion root inhibitors provide physical + chemical double blocking of root penetration, passing the FLL R1 level root resistance test (the strictest level).

Waterproof Protection: The dense inorganic structure + nano-waterproof coating form a "rigid waterproof base layer", which, when combined with a flexible waterproof membrane (such as TPO), forms a "rigid-flexible combined waterproofing system" to solve the problem of easy damage to single flexible waterproofing by root penetration or aging.

Key Advantage: No swelling or deformation when exposed to water, no brine return phenomenon, avoiding water penetration into the roof structure layer, and adapting to the long-term humid environment of green roofs.

 

3. Core Function 3: Structural Load-Bearing Layer (Green Roof Load Optimization)

Application Pain Point: The growing medium (150-300kg/㎡) + plants (20-50kg/㎡) + rainwater (50-100kg/㎡) of green roofs generate large loads. Traditional concrete boards (density 2400kg/m³) significantly increase roof structural pressure, and even require reinforcement of the original building.

MGO Board Solution: Lightweight and high-strength characteristics (density is only 1/3 of concrete), 15mm thick MGO Board can bear a uniform load of ≥2.0kN/㎡, fully meeting the load-bearing requirements of medium-sized green roofs (growing medium thickness 15-30cm) without additional roof structure reinforcement.

Key Advantage: Customizable thickness (8-25mm). 8-10mm boards are used for lightweight green roofs (growing medium ≤15cm), and 18-25mm thickened boards are used for load-bearing scenarios (such as green roofs and solar panels), flexibly adapting to different load scenarios.

 

4. Auxiliary Function: Drainage Guidance and Ecological Compatibility

Drainage Guidance: The surface can be customized with grooved textures (10mm wide × 5mm deep) to form natural drainage channels, guiding rainwater to quickly flow into the drainage layer and avoiding waterlogging in the growing medium that causes plant root rot.

Ecological Compatibility: Formaldehyde-free and neutral pH value, no harmful substances released to pollute soil or plants, and the board is recyclable, in line with the core concept of "low carbon and ecology" of green roofs.

 

Application Solutions of Fireproof MGO Board in Different Types of Green Roofs

1. Green Roofs of Public Buildings (Shopping Malls, Hospitals, Schools, Office Buildings)

Application Scenarios: Large-area roof gardens, landscape green roofs, integrated photovoltaic + green roofs.

Core Requirements: Fire safety compliance (Class A1), controllable load, long-term maintenance-free, environmental friendliness and non-toxicity.

MGO Board Application Solution:

Select 12-15mm thick fireproof MGO Board (density 1000kg/m³) to serve as the fire barrier layer + root-resistant waterproof base layer.

The board edges adopt a locking design (equipped with EPDM rubber gaskets) to avoid water leakage or root penetration at the joints.

Adaptation to photovoltaic bracket installation: The board is pre-reserved with photovoltaic fixing holes (spacing 500mm×500mm), with a load-bearing capacity ≥30kg/㎡, realizing "greening + power generation" integration.

Case Reference: A green roof of an urban commercial complex (1000㎡) adopts 15mm fireproof MGO Board, combined with sedum plants and photovoltaic panels, passing LEED Gold certification and fire acceptance at one time. No water leakage or root damage has occurred in 3 years of operation.

 

2. Green Roofs of Residential Buildings (Villas, High-End Apartments, Affordable Housing)

Application Scenarios: Private roof gardens, balcony greening, community shared green spaces.

Core Requirements: Lightweight, waterproof, root-resistant, easy construction, no soil pollution.

MGO Board Application Solution:

Select 8-12mm thick lightweight MGO Board (density 950kg/m³) to reduce roof load and adapt to residential roof structures.

The surface is sanded to facilitate bonding with the drainage layer (ceramsite, plastic drainage board) and improve drainage efficiency.

Environmental properties: Zero formaldehyde emissions, no impact on indoor air quality, no heavy metal residues in the soil, ensuring safe plant growth.

Advantage Highlight: Fast construction, 2-3 workers can install 80-100㎡ per day, no large equipment required, suitable for efficient construction of residential projects.

 

3. Green Roofs of Industrial Plants (Electronics Factories, Food Factories, Warehousing and Logistics Centers)

Application Scenarios: Factory roof greening, heat insulation and cooling roofs, fire safety-compliant green roofs.

Core Requirements: Fire retardancy (industrial building fire codes), corrosion resistance, high temperature resistance, easy maintenance.

MGO Board Application Solution:

Select 15-18mm thick reinforced MGO Board (compressive strength ≥28MPa) to adapt to large-area factory roofs (column-free spans).

The surface is compounded with a fluorocarbon coating to resist corrosion from industrial waste gas (such as chemical parks), passing the ASTM B117 500-hour salt spray test.

Fire barrier: Blocks fire spread from the factory interior to the roof, and prevents fires in the roof greening layer (such as plant spontaneous combustion in dry seasons) from affecting indoor equipment.

Value Embodiment: Green roof + MGO Board heat insulation (thermal conductivity ≤0.18 W/(m·K)) can reduce the indoor temperature of the factory by 3-5℃ and reduce air conditioning energy consumption by 15-20%.

 

4. Green Roofs for Old Building Renovation (Historic Buildings, Old Communities, Old Factory Renovation)

Application Scenarios: Green roof upgrading of old buildings, fire safety compliance renovation, load-restricted roofs.

Core Requirements: Lightweight (insufficient load capacity of the original structure), simple construction (no damage to the original roof), fire safety upgrading.

MGO Board Application Solution:

Select 6-8mm ultra-thin MGO Board (weight ≤10kg/㎡), which can be directly laid on the original roof (such as asphalt shingles, concrete base) without removing the old roof, reducing renovation costs.

Adopt a composite fixing method of bonding + mechanical fixing to avoid punching and damaging the original waterproof while enhancing stability.

Fire safety upgrading: Upgrade the original combustible roof (such as wooden roof, asphalt roof) to a Class A1 non-combustible roof, meeting the fire safety renovation requirements of old buildings.

Case Reference: Renovation of an old teaching building roof (800㎡). The original roof was asphalt shingles (flammable). 8mm fireproof MGO Board + thin-layer growing medium (10cm) were used, with a load increase of only 120kg/㎡. The original structure met the standards without reinforcement, and greening, heat insulation, and fire safety upgrading were realized simultaneously.

 

Installation Process and Key Node Treatment of Fireproof MGO Board in Green Roofs

1. Standard Installation Process (Adapting to Green Roof Construction Logic)

Base Preparation: Clean the roof structure layer (concrete/steel structure) to ensure it is flat and dry (moisture content ≤12%), and repair cracks or damages.

Insulation Layer Laying (if required): Lay XPS/rock wool insulation boards (thickness 20-50mm) to form a "thermal insulation + fire protection" composite layer with MGO Board.

MGO Board Laying:

Lay the boards perpendicular to the roof purlins/beams, leaving 3-5mm expansion gaps (filled with fireproof sealant).

Fix with 316L stainless steel self-tapping screws (spacing 150mm along the edges, 250mm in the middle of the board). Install EPDM waterproof washers on the top of the screws to avoid water seepage.

Locking splicing: Adopt tongue-and-groove locking design, and paste root-resistant waterproof tape at the joints for double protection.

Waterproof Layer Enhancement: Lay a TPO/PVC flexible waterproof membrane (hot air welding) on the surface of MGO Board to form a "rigid + flexible" combined waterproofing system.

Drainage Layer and Filter Layer: Lay plastic drainage boards (thickness 20-30mm) + non-woven filter layers to guide rainwater discharge and prevent clogging of drainage channels by growing medium.

Growing Medium Laying: Lay lightweight growing medium (10-30cm, density ≤1200kg/m³) and plant suitable plants such as sedums, sedum lineare, and shrubs.

 

2. Key Node Treatment (Core to Avoid Water Leakage and Root Penetration)

Parapet Wall Node: Extend MGO Board 150mm to the inner side of the parapet wall, fix the top with metal pressure strips, and apply waterproof coating on the outer side to prevent rainwater penetration from the joint between the parapet wall and the board.

Pipe Penetration Node: The opening size of the board is 20mm larger than the pipe diameter. Wrap the hole circumference with root-resistant waterproof membrane, fill with fireproof sealant, and install a metal sleeve on the outer side to block root penetration around the pipe.

Roof Corner Node: Use customized curved MGO Board (minimum bending radius ≥5m) to avoid cracks caused by right-angle splicing, and additionally paste root-resistant tape at the joints.

Drainage Outlet Node: Reserve a 1-2% slope on the MGO Board towards the drainage outlet to ensure rapid collection and discharge of rainwater. Install a filter screen around the drainage outlet to prevent clogging by growing medium.

 

Performance Comparison Between Fireproof MGO Board and Traditional Green Roof Materials

Performance Indicator	Fireproof MGO Board	Concrete Board	Fiber Cement Board	Wooden Board
Fire Rating	Class A1 (Non-combustible)	Class A1 (Non-combustible)	Class A2 (Hardly Combustible)	Flammable (Class B3)
Density (kg/m³)	900-1050	2400	1800	600-800
Root Penetration Resistance	FLL R1 (Excellent)	None (requires additional root barrier membrane)	None (requires additional root barrier membrane)	Poor (easily damaged by roots)
Water Absorption Rate	≤4%	10-15%	12-18%	20-30%
Service Life	≥60 years	30-40 years (prone to cracking)	20-30 years (prone to weathering)	5-10 years (prone to rotting)
Environmental Properties	Formaldehyde-free, recyclable, neutral pH	Formaldehyde-free, non-recyclable	Low VOC, non-recyclable	Formaldehyde-containing, recyclable but prone to soil pollution
Construction Efficiency (㎡/person/day)	30-40	10-15	15-20	25-30 (but requires additional fire/root resistance treatment)

 

Sustainable Value and Certification Adaptation of Fireproof MGO Board in Green Roofs

1. Sustainable Development Value

Low Carbon Emission Reduction: The production energy consumption is 60% lower than that of concrete boards, with a carbon footprint of only 8kg CO₂eq/㎡. It is 100% recyclable (old boards can be crushed into road base materials or reused as raw materials for new MGO boards).

Ecological Protection: Neutral pH value does not pollute soil or groundwater, no heavy metal residues, ensuring plant diversity and helping to alleviate the urban heat island effect (green roof + MGO Board heat insulation can reduce the regional temperature by 1-2℃).

Whole Life Cycle Cost Advantage: The initial investment is 15-20% higher than that of concrete boards, but no additional fire protection, root resistance, or waterproof maintenance is required, and the service life is extended by 50%, reducing the whole life cycle cost by 30-40%.

2. International Certification Adaptation (Helping Green Building Rating)

Fire Certification: EN 13501-1 Class A1, ASTM E136 Class A;

Green Roof Certification: FLL Green Roof Standard, German DIBt Certification;

Environmental Certification: EU REACH, US CARB P2, LEED v4 (contributing 3-5 points), BREEAM (points for materials and ecological sections).