How to prevent mgo board corrode steel?

Views:7619     Author:Rockmax     Publish Time: 2018-12-13 


Magnesium oxide board is grade A1 fireproof wall board,been famous for exceptional fireproof performance,high bending strength and light weight.Soon mgo board brings huge impact to traditional wall panel,such as fiber cement board,Gypsum board,OSB and MDF.
It is manufacture and export from China,distribute in different countries,which involved in many international projects.

In recently,we found some negative information about mgo board on internet,market start to confuse about this material.
Rockmax has been researched and developed chloride free mgo board over 10 years.Here are some experiences for share.

What is mgo board?
Magnesium oxide board or “mgo board” in short,it’s flat wall panel,thickness range from 4mm-30mm
It consist of 3 element,(magnesium oxide),(salt) and (water).

Why,most of mgo board come from China?
Magnesium oxide is one of the best fireproof material in the world.
Most of magnesium oxide mine located in Changbai Mountain,north part of China and North Korea.
Chinese use magnesium concrete can be track back to hundred years.

How many kinds of mgo board?
MgO boards predominately come in three different types:
magnesium oxychloride hydrate
magnesium oxysulfate hydrate
magnesium oxyphosphate hydrate
They are fomulated with different salt.
Most of mgo board export from China is magnesium oxychloride hydrate type,
which has risk of corrosion to steel.

Why Mgo board(magnesium oxychloride hydrate) corrode steel?
Metallic corrosion is the process of either stealing or donating electrons, when the electrons are stolen or donated, the metal atoms will dissolve in the water. Salt water is a the main conductor, so the rate of corrosion increases dramatically. When mgo board in high humidty enviroment(80%),inside chloride iron will dissolve and move toward water,when it contact with metal,unavoidale corrosion will happen on its surface.

How to prevent magnesium chloride board corrode steel?
1-Replace steel frame and screw by stainess screw and stainless frame, aluminmium frame or wood frame.
2-Laminate a plastic film on reverse of mgo or add one layer of gypsum board as underlayment of mgo.
3-Dismantle magnesium chloride board,replace by chloride free mgo board

What would happen if someone use magnesium chloride board with steel frame or galvanized frame?
1-screws and frame attack by chloride ions and get rust in humidity
2-panel get damp and regain in rainy days,frequency wet and dry cause plaster mold and crack
3-panel get powery cause plaster delamination
4-panel has risk of cracking at screw point or joint after few months

How to know mgo board contains chloride or not?
1-Prepare a cup of purified water,immerse some screw and small pieces of mgo board,check steel corrosion after 15 days.
2-Contact local testing lab,SGS or Intertek. Apply a chloride content inspection,cost about $300-400, 7 working days.

Some examples about mgo board(magnesium oxychloride hydrate) corrosion

No.1 Interior Partiton Corrosion
A piece of magnesium chloride board fasten on steel frame by standard self-drilling screw,indoor condition.

After 6 months,all the screw get rust and plenty of powder came out on the surface.

No.2 Basement Air duct corrosion

Magnesium chloride board 15mm-18mm has been widely use for ventlating duct in China.
In basement environment,magnesium chloride absorb humidity,salt liquid corrode steel fast and damp badly.
Now Chinese air duct association issued mandatory regulation that chloride content of mgo air duct have to be less than 1%

No.3 Exterior sheathing corrosion

Exterior sheathing case.corrode frame badly,frame system destroyed after 4 year.


New regulation for export mgo board

Now Chinese Magnesium oxide board industry association issued new regulation for export mgo board
on June 11th,2018
All the chloride mgo board have to indicate limitation and application environment.
“This product shall not be directly contacted with metal parts without rust treatment”

“This product limited to indoor and other non humid condition” unless it has special waterproof treatment


1,ROCKMAX is new generation chloride free mgo board, do not have any corrosion risks.
2,ROCKMAX is approved panel,test in full
3,ROCKMAX’s material safety meet European “REACH”,exclude 191 kinds of harmful material may effect health.
4,ROCKMAX provide guarrantee for steel frame system safty,compensate 200%(chloride>0.5%) on CNF price
To choose more green and safe mgo board,please kindly contact ROCKMAX sales team.