MgO Subfloor FAQs – All Your Concerns Answered

Although Magnesium Oxide boards have been around for quite some time, they’ve only recently regained popularity in the construction industry. As such, many contractors are still unsure about their complete range of applications and recommended uses.


As a global supply chain leader in fire-rated structural panels, we often get asked about the use of MgO boards for subflooring. To help our readers better understand the applications of MgO subflooring, we’ve compiled a list of frequently asked questions and answered them right here.


Let’s start.


Can MgO be used as a subfloor?


Yes, MgO boards can be used as subfloors, as long as they meet specific thickness and strength requirements. These requirements vary depending on the floor design, joist span, size, and live loading factors.


At MagMatrix, we offer a range of MgO panels designed specifically for subflooring purposes. MagMatrix Premier® Fire-Rated Structural Subflooring comes with a density of 1400 kg/m³ and offers excellent bending and structural capacity for subflooring applications.


What is the best way to cut MgO boards?


MgO board panels are available in several standard sizes. However, in case you need to cut them, we recommend using a thin carbide circular saw. A sharp disposable razor knife might be able to cut the through but won’t give you a smooth, clean edge.


If you are using a knife, make sure the corners are glued adequately to prevent micro-cracking.


How do MgO boards compare in cost with other wall boards?


The cost per sheet of a magnesium oxide board is higher compared to regular gypsum boards. There are economy versions of MgO boards that offer durability and are cost-effective too.


It is essential to note that MgO boards do provide cost savings during the finishing process. Unlike Portland cement, MgO boards don’t require three coats of drywall tape or corner beads.



What finish can I use on MgO boards?

Primer works best as a finish for MgO boards since they’re alkaline in nature. Polymer-modified cement base coats and acrylic stucco topcoats work well will MgO Boards too.

Powder-coating and painting MgO boards are also suitable forms of finish. However, we recommend carrying out a cross-hatch test first to see if it can bond well with your panels.


Buy High-Quality MgO Subfloor Boards


Choosing a reliable manufacturer is critical when choosing MgO subflooring panels. At MagMatrix, we own the industry’s most advanced production facility, and we routinely carry out quality inspection tests to ensure our products meet high-quality standards.


We offer a variety of MgO board products such as fire-resistant flooring boards, sheathing boards, and subfloor panels to our clients.


For more information, drop us a message or call 86-335-3327878

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