Not all the mgo board suit for external wall!

Views:619     Author:Rockmax     Publish Time: 2016-12-13 


Today mgo board plays an important role in fireproof building materials industry.

Mgo has better fireproof and lower heat transfer than fiber cement board and gypsum board,bending strength and flexibility almost double.

Mgo is termite resistant and mildew proof,better than wood,but price is similiar.

In recently,we found some negative informations about mgo board for external applications

it may involved panel bending or cracking at joint,decoration material delamination,tile,marble fall off.

People start to confuse about mgo board for exterior wall.

Rockmax has been research and design magnesium oxide cement over 10 years,we are good at mgo evaluation,

mgo aging theory and test.Here are some experiences for share.

  • Most of mgo board sell on the market,can only use as interior wall in low humid condition
  • Exterior grade mgo board is a technical product.It is base on scientific reinforcement design,selected raw material and climate resistant treatment.In China,few of producers can produce exterior grade mgo board and provide accordingly test report.
  • If wrong mgo put in the wrong place,without appropriate treatment and paint,repair or rebuild can not escape.

The most difficult part is magnesium oxide board,looks the same.

Many un-professional trader or producer don’t have mature technology or don’t know stardard requirement,

they try to sell heavy interior use mgo board at best quality price.

Problem start from Supplier – Distrbutor – Designer – Builder – End User


Mgo board has different type and different quality level,basiclly has 3 type in China

  • magnesium oxychloride hydrate
  • magnesium oxysulfate hydrate
  • magnesium oxyphosphate hydrate

They are fomulated with different kind of salt and different characteristics.

For example:

magnesium oxychloride hydrate can not use in steel structural frame system

magnesium board can not use in exterior wall without additional waterpoof treatment and appropriate paint.


  • Check durability report,exterior wall panel has durability requirement,strength remain above 0.75
  • Low water absorption rate and low wet expansion rate


  • Mgo can not use in exterior load bearing or hanging system
  • Chloride mgo board can install on steel frame
  • It is necessary to design rain cavity or use wall wrap to minimize moisture and heat exchange.

End users 

  • Check durability and chloride content test report before check price
  • Buy insurrance

ROCKMAX is one of the leading MGSO panel in China,it is chlorie free, climate resistant.

we have passed climate resistant test in Stuttgart,Germany and full durability test has been done in SGS Shanghai,

durablity test  to EN ISO 12467 -2012, Grade A class 3.

Conclusion is

After the completion of 50 heat-rain cycles the wall was inspected for damage.

The complete wall surface exhibited no cracks, delamination, deformation or bending, see Figure 2,

Enclosure 2. One of the boards exhibited slight lime efflorescence, as shown in Figure 2, Enclosure 2.

Based on these results it can be concluded that the tested product meets the requirements of EN 12467, 5.5.3.