How to Set Up an MgO Board Plant: Planning Guide for Investors

This guide is for building-materials companies, investors and project developers evaluating a new plant for magnesium oxide (MgO) boards — the glass-fibre reinforced magnesia boards used for partitions, ceilings, linings, sheathing and tile backer. It is written by the YuxingCorp project team and covers single lines of 1 to 3 million m² a year.

It does not quote prices. An MgO board plant is configured around its boards, its raw materials, its climate and its site, and a figure given without those inputs would mislead more than it helps. Instead, this guide sets out the decisions to make first, what the markets you sell into will ask of your boards, how to secure raw materials, the equipment a complete line needs, the planning sequence we work through with buyers, the problems to avoid in a first plant, and a checklist you can send to any supplier so the proposals you receive can be compared line by line.

Last updated: October 2026

1. First, decide which board you will make

Sulfate or chloride binder. MgO boards are bound with one of two magnesia cements. Magnesium oxysulfate (sulfate) boards contain no chloride ions, so they do not sweat brine in humid weather or corrode steel studs, screws and fixings; their softening coefficient can reach 0.9, meaning they keep about 90% of their strength after long immersion in water. Magnesium oxychloride (chloride) boards are the traditional formulation. At high density they are tougher in bending, which keeps them in use where heavy hanging loads matter, but chloride attracts moisture and attacks metal. Our MgO board lines make sulfate boards.

Applications. Decide which uses you will sell into — partitions, ceilings, internal linings, external sheathing or tile backer. Each sets its own density, thickness and test programme, and external and humid uses are where most problems with MgO boards have been reported (see section 2).

Sizes and density. The standard sheet is 2440 × 1220 mm; 2400 × 1200 and 3000 × 1220 mm are also common. Thickness runs from 3 to 20 mm, most commonly 3–12 mm, at a density of 1.2–1.4 g/cm³. Fix your thickness range early: it sets up forming and trimming.

Plain or decorative. Boards can be given stone, wood-grain or high-gloss finishes on a UV coating line, in the same project or as a later upgrade.

2. Know what your markets will ask of the board

MgO board has a mixed record, and buyers, insurers and building officials in several markets now ask hard questions. Knowing why helps you choose the formula and the tests from the start.

Denmark. MgO boards were the wind barrier of choice on Danish facades from 2010 until moisture problems surfaced at the end of 2014. Hundreds of buildings were affected, and the industry put possible damage at over DKK 1 billion (The Copenhagen Post, 2015).
Canada. The Canadian Construction Materials Centre advised building officials to avoid MgO boards it has not evaluated in conditions above 84% relative humidity and in direct contact with metal other than stainless-steel fasteners, citing Danish and Australian findings on moisture and corrosion (CCMC advisory, updated 2018).
United Kingdom. The housing warranty providers NHBC, Premier Guarantee and LABC stopped accepting MgO boards on the schemes they insure in 2020 (RICS, 2021). In September 2021 BSI published PAS 670, a specification for magnesium oxychloride and magnesium oxysulfate boards for partitions and internal and external linings, including their performance in a humid environment; flooring, sarking and roofing are outside its scope.
New Zealand. BRANZ kept four boards for 90 days at 30 °C and 90% relative humidity. Non-stainless screws corroded in the two higher-chloride boards while stainless-steel screws (grades 304 and 316) did not — and all four boards, including the two that appeared to use a sulfate-type binder, exceeded the PAS 670 humidity acceptance criteria (BRANZ, 2023).
North America. ICC 1125-2026 sets requirements for MgO boards — flexural strength, moisture movement, freeze–thaw durability, corrosion resistance and surface burning — for wall sheathing, tile backer, and floor and roof sheathing (International Code Council).

The lesson for a new plant: a sulfate binder removes the chloride problem, but it does not on its own make a board pass a humidity test — the formula, the quality of the magnesium oxide and the curing decide that. Choose the standard you will test to — PAS 670, ICC 1125 or the one your customers specify — before the line is ordered, and plan factory testing around it.

3. Raw materials: what the plant buys

An MgO board line does not make its own binder; it buys it in:

Light-burned (caustic-calcined) magnesium oxide, with 60–80% active MgO
Magnesium sulfate, made up as a 15–25% solution
Fillers such as wood chips, bamboo powder or calcium carbonate powder
Glass-fibre mesh for reinforcement

Calcining magnesite and producing magnesium sulfate are separate upstream industries. The activity and purity of the magnesium oxide decide board strength and stability, and they vary between suppliers and between lots.

Supply is concentrated. China mined 12.9 million of the world’s 21.1 million tonnes of magnesite in 2024, and Liaoning, its main producing province, is consolidating the sector: magnesite-mining companies there fell from 114 in 2020 to 63 in 2024 (USGS, 2026). Brazil, Russia and Turkey each mined 1.6–1.9 million tonnes.

Three practical steps: test the magnesium oxide and magnesium sulfate you can actually buy before the formula is fixed; qualify at least two magnesium oxide sources, so one supplier or one bad lot cannot stop the plant; and check the activity of every incoming lot before it goes into production.

4. What decides plant size and layout

Output. One line produces 1–3 million m² of board a year. Size the plant against the volume your local market can absorb, not the largest line on offer.

Curing. There is no autoclave and no steam boiler: boards cure at ambient temperature, in stages — an initial cure that sets the board and drives off water, a second cure and a final deep cure — before they are trimmed. Plan the building around the curing stacks as well as the forming line. For a 1 million m² a year line, allow 8,000–12,000 m² of buildings on about 1.3–2.7 ha (20–40 mu).

Climate. Magnesium sulfate boards harden slowly. In cold climates, or to shorten the cycle, add a heated curing room; decide with the site’s winter temperatures in hand.

Power and water. Confirm the supply voltage, frequency (60 Hz in Saudi Arabia, for example) and available capacity before the electrical design is fixed.

5. The equipment in a complete line

Batching and mixing → roller-pressed forming in layers with glass-fibre mesh → stacking → curing → demoulding → further curing → trimming, sanding and inspection → packing.

Raw material handling: magnesium oxide storage and dosing, magnesium sulfate dissolving and solution tanks, filler dosing
Mixing: slurry mixers matched to the forming speed
Forming: roller-pressed layered forming with glass-fibre mesh, on templates
Stacking and template handling
Curing: natural curing area; heated curing room as an option
Demoulding and template return
Finishing: trimming, sanding and inspection
Packing
Quality laboratory: magnesium oxide activity, board density, bending strength and moisture behaviour
Option: a UV coating line for decorative boards

6. Timeline: seven stages from brief to stable production

Stage 1: Define the requirement. Board types and applications, sizes, thickness and density, the standard you will test to, annual output, raw material sources, winter temperatures at the site, the site itself and the target timeline.

Stage 2: Raw material testing and supplier comparison. The magnesium oxide and magnesium sulfate you can source are tested and the formula is confirmed before the line configuration is final. Configurations from different manufacturers are compared against the same brief, so differences in scope and inspection terms are visible before price is discussed. Our commitment: “A written sourcing report within 48 hours of a complete requirement brief.” “Custom or multi-line projects may take longer — we tell you upfront.”

Stage 3: Contract and payment. Standard terms: T/T 30% deposit, 70% balance before shipment. “We confirm which certificates are available before contract.”

Stage 4: Manufacturing and pre-shipment inspection. Equipment delivery takes about 2–3 months after the deposit. “Every shipment comes with a full pre-shipment inspection report — test-run records, functional and dimensional checks, photos and video — before the equipment leaves the factory.” Third-party inspection (e.g. SGS, BV) can be arranged on request; the fee is paid by the buyer and is not included in the equipment price.

Stage 5: Export documents and shipment. “Complete export document pack — commercial invoice, packing list, certificate of origin, bill of lading, and manufacturer certificates such as CE or EAC where applicable.” We coordinate shipping and freight logistics. “Import customs clearance, duties, taxes and local registration are the buyer’s responsibility.”

Stage 6: Installation and commissioning. We send 3–4 engineers to supervise installation, commissioning and trial production, typically on site for 2–3 months, depending on the progress of civil works. Travel and accommodation are at the buyer’s cost. Because boards cure before they are trimmed, the first finished boards come some time after the first forming run — plan your market launch around it.

Stage 7: Training, running-in and warranty. Your operators and maintenance staff are trained during installation and trial production, with remote technical support afterwards. “12-month equipment warranty from the date of commissioning, with a named responsible contact.”

7. Checklist: what to prepare before you request quotes

Send the same list to every supplier you are talking to. Proposals built on the same inputs are the only ones you can compare.

Board type: sulfate, or chloride for specific uses
Applications: partitions, ceilings, linings, external sheathing, tile backer
Sizes, thickness range and density
The standard your customers specify (PAS 670, ICC 1125 or local)
Annual output target (m² a year)
Magnesium oxide sources with activity and purity, magnesium sulfate, fillers and glass-fibre mesh — and whether you can send samples for testing
Climate at the site, especially winter temperatures, and whether you want a heated curing room
Decorative finish now, later or not at all
Power supply: voltage, frequency and available capacity; water supply
Site: land and building dimensions; new building or existing
Who will carry out the civil works
Destination country and target timeline

8. Seven problems to avoid in a first MgO board plant

Making chloride boards for humid or external uses. Chloride attracts moisture and attacks metal, and the documented problems in Denmark, Canada, Australia and New Zealand involve humid conditions. Make sulfate boards; keep chloride boards for interior uses that need their bending strength.
Fixing the formula before testing your magnesium oxide. Activity and purity vary between suppliers and lots. Test the sources you can actually buy and confirm the formula with trial boards.
Depending on one magnesium oxide supplier. Supply is concentrated in a few countries and is being consolidated in China. Qualify a second source before production starts.
Choosing the standard after the first batch. If your customers buy to PAS 670 or ICC 1125, the humidity, moisture-movement and corrosion tests shape the formula and the curing. Plan them from the start.
Testing the board but not the fixings. In the BRANZ tests, stainless-steel screws were unaffected where plated screws corroded. Test your boards with the screws and studs your customers will use, and state the fixings in your installation guide.
Too little curing space, or no heat in a cold climate. Output is limited by how many boards can cure at once, not only by forming speed, and magnesium sulfate boards harden slowly in the cold. Size the curing area for the full output and add a heated curing room where winters are cold.
Exporting without the approvals your buyers need. In the UK, warranty providers stopped accepting MgO boards in 2020; in Canada, building officials are advised to avoid boards CCMC has not evaluated in humid conditions. Find out which certification your target markets require before you plan exports.

9. MgO board plant FAQs

Sulfate or chloride MgO board — which should we make?

For most wall, ceiling and substrate boards, magnesium sulfate: no chloride, no brine sweating and no corrosion of steel studs or fixings. For boards that must carry heavy hanging loads, high-density chloride board is tougher in bending.

Do we need an autoclave or a boiler?

No. Boards cure at ambient temperature. A heated curing room is an option for cold climates or a shorter cycle.

Which capacity should we start with?

One line produces 1–3 million m² a year. We help you size it against your local market demand.

How long does a project take?

Equipment delivery takes about 2–3 months after the deposit. Installation, commissioning and trial production then take typically 2–3 months on site with 3–4 of our engineers, depending on civil works.

How much land and building do we need?

For a 1 million m² a year line, 8,000–12,000 m² of buildings on about 1.3–2.7 ha (20–40 mu).

Which standards can the boards be made to?

Tell us the standard your customers specify — for example PAS 670 in the UK or ICC 1125 in North America — and the formula, curing and factory testing are planned around it. Certification itself is issued by test laboratories and certification bodies in your market.

Can you supply the magnesium oxide?

The board line buys light-burned magnesium oxide and magnesium sulfate in; calcining and magnesium sulfate production are separate upstream industries. Test the sources available to you before the formula is fixed.

What do you need to prepare a proposal?

Your board types and applications, sizes, thickness and density, target output, the standard, raw material sources, site climate, project location and planned timeline.

10. What we handle

Equipment sourcing & supplier coordination
Pre-shipment quality inspection report; third-party inspection on request (buyer’s cost)
Export documentation — invoice, packing list, certificate of origin, bill of lading
Manufacturer certificates (e.g. CE, EAC) where available
Shipping & freight logistics coordination
Installation guidance & commissioning support

11. Related

Planning an MgO board plant?

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