What The Heck Is MDF Anyway?

Posted by Vinnie Rouge on 4/10/2015 to Buying Guide - Living Room
What The Heck Is MDF Anyway?
This Buying Guide Will:
  • Tell you in detail exactly what MDF is
  • Address the two biggest concerns about MDF
  • List MDF's advantages and disadvantages
MDF is an extremely common material used in furniture. However, a lot of shoppers who are confronted with the term have one of two reactions, both negative. They may not know what this material actually is at all. Or if they do, they may also write it off as substandard. I'll break down for you what MDF is and the positives and negatives of furniture made from it.

MDF stands for Medium Density Fibreboard. 

Fibreboard, in all its densities, is made from wood fibres. Those would be little tiny pieces of hardwood or softwood. Mix these with some resin and wax, then heat it up and press it together, and you get fibreboard.

That explains fibreboard, you say, now what about medium density? Medium relative to what? 
Low density fibreboard is usually called particle board. Particle board is made out of even smaller pieces than MDF - even sawdust can be used to make particle board. That makes particle board inexpensive, but it also makes it weaker than MDF.
There is also such a thing as high density fibreboard, and it has its own name too - hardboard. To make hardboard, more heat and pressure is required than with the other fibreboards, but adhesives are usually not required. Hardboard is quite strong, but can also be an expensive material.
Want some numbers to compare the usual densities of fibreboards? Here you go:

What is MDF

The Two Most Common Concerns About MDF

"Do manufacturers and stores use MDF with veneer on it and then tell people the piece is solid wood?"

While MDF furniture with veneer on top to simulate solid wood is a popular choice, the reason for that choice has nothing to do with deception. By using veneer over MDF, a manufacturer can create furniture that has the look of woods that would not otherwise be available. Some of these woods are excessively expensive; they may be rare and environmentally protected; or they may simply not make good solid wood furniture.
I do agree that it makes perfect sense to want to know what materials furniture is made of before you purchase it. If in doubt - ask! A competent salesperson will know the answer or be able to help you find it. 

"Are the chemicals in MDF poisonous? Do they cause cancer?"

Generally, people who ask these questions are thinking primarily about formaldehyde. That chemical is used in the construction of MDF, and there have been studies linking formaldehyde with an increased risk of cancer. However, there are two important counterpoints to consider here.
First, there are increasingly strict government restrictions in place covering the amount of chemicals, especially formaldehyde, that may be used in the construction of MDF. 
Second, what off-gassing of formaldehyde does occur happens primarily during the construction of the material. By the time the piece reaches your home, especially if it has been painted, off-gassing has for the most part halted. 
If you would like more information on formaldehyde and its potential health effects, this link will take you to the Air Quality Guideline document produced by Health Canada on the subject.

Here is a breakdown of many advantages and disadvantages of MDF as used in furniture. Since people considering purchasing MDF furniture often want to know how it compares to solid wood, you will see a lot of comparisons to that here.

Advantages of MDF Furniture
  • MDF is an economical choice. It's inexpensive to make so you will pay less for it in the store than for some solid wood pieces.
  • MDF uses recycled wood in its construction, thereby helping to save trees.
  • MDF is easy to paint in many different colours, whereas solid wood has a difficult time taking some colours.
  • A smooth material throughout, MDF does not have knots that can blemish the surface of a piece or make components difficult to attach.
  • The chemicals used in the construction of MDF make it poisonous to pests such as termites.
  • MDF will not expand and contract due to heat and humidity the way solid wood can.
  • Shaping MDF is easier than shaping solid wood, making it easier to do more elaborate designs.
  • Veneer can easily be attached to MDF to give it the look of genuine wood. 
Disadvantages of MDF Furniture
  • As noted above, when MDF is being constructed, it may off-gas small amounts of formaldehyde, though this has largely dissipated by the end of the construction process. MDF which has been painted reduces any health risk still further.
  • MDF tends to be high maintenance - if you chip it or crack it, you cannot repair or cover the damage easily as you typically can with solid wood.
  • The chemicals used in making MDF make the material less child-friendly than other materials.
  • Direct exposure to water can cause MDF to swell.
  • There is no grain on MDF, as it is not a natural wood product. If this is an issue, however, it is easily remedied with veneer.
  • The glue present in MDF can make it hard to sink certain types of fasteners into the material. 
How do you feel about MDF? Love it or hate it, we want to hear from you in the comments!