Types of wooden flooring, In-depth guide to floorboards, Plywood, Chipboard, and MDF
We all know that buildings need to have floors to walk on and allow us to move easily around on different levels.
When it comes time to repair or replace your flooring, understanding which types are available and which option you should choose can save you thousands of dollars, change the look of your property and add value to your home.
The word ‘flooring’ is used in building construction as a general term describing the surface installed on top of the main structural elements of the building which form each level, ground floor, first floor etc.
Generally the main structure is made from timber or steel joists or a concrete slab and the covering surface may be made from softwood or hardwood planks or from a type of man-made boarding.
Let’s look at the options available for wooden flooring and their Pros and cons:
What are Floorboards?
Wooden floorboards are made from softwoods like pine or Spruce, boards used in property construction are 5.0” (125mm) x 1.0” (25mm) wide by 8ft (2400mm) long, they are supplied PAR which means ‘Planed All Round’ and have either square edges or have tongue and grooves (PTG) cut on either long edge.
The Tongue and groove allows the boards to be joined together and form a strong, connected surface to walk on, the groove is usually offset from the center of the board and they should be laid with the tongue closest to the joists.
Standard floor board sizes available are generally 5.0” (125mm) x 1.0” (25mm) or 6.0” (150mm) by 1.0” (25mm).
What is a Nominal size floorboard?
These sizes specified on the timbers description are considered as ‘Nominal’ dimensions and refer to the timbers boards’ unfinished size.
For example, a nominal 2” (50mm) × 4” (100mm) board, is rough sawn to approximately 2” x 4” overall width and thickness.
A finished board which has been planed smooth and is stated as nominal 2” (50mm) × 4” (100mm) will be reduced to its finished size of 1-½ “ (38.1mm) x 3-½” (88.9mm)
The finished boards are produced from the rough saw blanks and as such the slightly small size will be the actual cut size of the wood,
It is worth noting and remembering this whenever you use timber planks or stock, as these final dimensions need to be used when you plan and work out your DIY project.
Types of high grade floorboard
These sizes are the most commonly used in modern construction; although floorboards as narrow as 3.0” (75mm) and as wide as 11.0” (280mm) wide can be found in some homes and older properties.
Narrow floorboards generally produce better quality floors than wider boards, as the grain is better controlled from the cut wood and the smaller size helps to reduce any shrinkage.
The downside to using narrower floorboards comes as higher costs for materials and installation. Narrower 3” floorboards are often used to produce high-grade floors and are typically made from more expensive materials like Oak or Maple.
High-grade, solid hardwood floors are often used as a feature in more expensive properties and can add value to the property if fitted correctly.
The best quality floorboards are cut from the log at the wood mill, using a method known as ‘Quarter sawn’. This method helps reduce any distortion that may come from shrinkage.
Quarter Sawn wood tends to be more expensive than other methods because fewer boards can be cut from the log and it produces more waste timber.
Tangentially cut floorboards
As not everyone needs to have the best hardwood floors fitted in their property, the more usual method for cutting flooring is by using a ‘tangential cut’.
These floorboards are widely available in big box stores, DIY, and hardware stores, but the best prices are usually found at the lumber mill.
This method allows for more boards to be cut from the same log reducing cost and producing less waste timber than the quarter-sawn method.
Tangentially cut floorboards are widely available and easy to source, however, boards cut like this often end up with some distortion and often cup or bow across the width.
To overcome this check the material you are going to purchase and select the least distorted sections,
the cut of a board tangential or quarter cut can be checked by looking at the annual growth rings on the end grain
Storing and Installing Floorboards
Floorboards need to be stored and fitted correctly to achieve the best results and long performance.
Store floorboards in a cool dry place, they should be laid flat and out of direct sunlight. Before installing, boards should be stored inside the building they are to be fitted and allowed to acclimatize for at least 24 hours, this helps prevent damage due to shrinking or expansion.
Before installing wooden floorboards check for cupping or bowing by looking along the length and using a flat edge, either a speed square or steel rule, however, it is often easy to see any distortion simply by eye.
I tend to discard any floorboards that have become overly cupped or warped, as they are more trouble to fit than they are worth, instead I cut them into shorter lengths for use in attics or storerooms or as short ends or fillers that can be hidden.
To overcome any distortion across the width of the board, they should be fixed with a concave side facing upwards, this will help prevent any splitting surfaces from facing upwards and reduce the problem of splintering.
When laying floorboards with a tongue and groove cut, the joint on tongue and groove is offset from the center and is closer to one face, these boards should be laid with the offset joint nearest to the joist.
Tongue and groove boards are normally a similar size to plane square edge boards, however, the groove joint reduces how far the flooring will cover by approximately ½” (12mm) per board when installed.
take a look at our guide to basic wood working joints for more ways to use and work with wood
Types of wooden Sheet flooring
Often when a higher quality and durable wooden surface is required as the finished level Softwood or hardwood floorboards provide an attractive surface, with good colour and depth when polished and sealed with varnish or wood stain.
For more functional uses and when a non-decorative wooden surface is required, using sheet flooring material such as flooring grade plywood or compressed particle boards is more practical, cheaper, and can be easier to install.
There are 3 main types of wooden sheet flooring, Plywood, Chipboard, and Medium Density fiberboard (MDF). They are available from ⅛” (3mm) thick up to 1.0” (25mm) thickness, a standard sheet is 8ft (2400mm) x 4ft (1220mm).
Plywood Sheet flooring
Plywood is a composite sheet material made up of several thin layers of wood bonded together with adhesive. Each layer is laid at 90 degrees to the previous layer, then a film of adhesive is applied between each layer, these are then pressed together until cured, this creates a strong, stable, and easy to use sheet material.
Most exterior grade plywood boards, also referred to as ‘WPB bonded plywood’ are suitable to use for flooring, plywood sheets are available in a range of thicknesses from ⅛” (3mm) up to 1.0” (25mm) and come in standard 8ft (2400mm) x4ft (1220mm) sheets.
Plywood sheets are often supplied with either a square edge or a tongue and groove finish on all 4 sides, this is specifically designed to be used as flooring, and interlocks in the same way as a solid wooden floorboard with tongue and groove edges,
When using plywood sheets as flooring laid directly over the structural joists, the plywood sheet needs to be at least ¾” (18mm) thick to provide enough strength to support normal domestic floor loadings.
Plywood sheets can also be used to level out an existing flooring surface and should be ¼” (6mm) or ½” (12mm) thick
Plywood is also often installed to provide a sub-base or underlay when laying tiles as the finishing surface. For this purpose ⅛” (3mm) or ¼” (6mm) thick sheets work well.
When used as a sub-base, plywood sheets are simply laid on top of the existing floor edge to edge and fixed with staples, pins, or small screws, ensuring the heads are flush or below the surface to avoid any issues with levels when laying tiles or the top, finishing surface.
I recommend that you use a level like this and don’t measure from the foot of the wall as it may not be plumb and this will put your soleplate in the wrong place.
With the stud marked out, you can cut and fix the 3” x2” (75mm x 50mm) sole plate to the floor, this can offer some issues depending on the orientation of the ceiling joists.
If the ceiling joists are parallel to the party wall, it is a good idea to fix additional noggins between them, this will provide secure fixing points for the lining head plate.
Chipboard Flooring
Chipboard is made from chips of wood compressed together with heat and resin, as the name suggests, to form a thin sheet material. There are several different grades of chipboard with moisture resistance and strength, only flooring grade sheets should be used as a flooring material.
Flooring grade chipboard which is also known as ‘Particleboard, is compressed to a higher density than the lower grades providing more strength and stability. Generally, it has a smoother surface without knots or andy voids making it stronger than lower grades
Originally chipboard was manufactured from the waste materials other wood processes created, in an effort to re-use as much material as possible and often incorporates a high percentage of recycled, chipped timber, typically between 65%-70%.
Chipboard is often used with other finishing techniques such as laminating and veneering and provides a stable and cheaper material for various uses including work surfaces and decorative shelving.
As with plywood, Chipboard is available in different grades and thicknesses, which allow the product to be used in structural and non-structural applications.
Flooring Grade chipboard is often supplied with slip-resistant and protective films, whilst Furniture Grade chipboard is used for veneering to provide a decorative, yet cost-effective, alternative to solid woods.
Flooring grade chipboard is produced with either square edge or tongue-in-groove edges, is normally ¾” (18mm) thick, and comes as standard in 8ft x 4ft sheets
Most manufacturers offer packs of pre-cut chipboard for small-scale projects like flooring out an attic or loft space, this allows most DIY’er to lift the boards through a loft hatch without having to cut or trim the boards.
When installing a chipboard floor in an area where moisture or dampness is present such as a bathroom or kitchen, then selecting a high moisture resistance grade is preferable to using a lesser grade.
Always measure and check the spacing between floor joists when using chipboard as the supported flooring surface, as it requires structural support.
¾” (18mm) thick boards are suitable for installing on joists that are no more than 1ft 4” (400mm) apart.
⅞” (22mm) thick boards should be installed over floor joists that are more than 1ft 4” (400mm) up to 2ft (600mm) apart, to provide enough support and strength to the finished flooring surface.
Medium Density Fiberboard MDF
Medium-density fibreboard (MDF) is made from fine, dense compressed wood fibers, pressed into sheet material. It is a high-quality, smooth, surfaced board with no naturally occurring defects or knots, and is produced in standard, moisture resistant, and exterior grades and is suitable for flooring where a plain smooth finish is required.
Like the other types of man-made, wooden board, MDF is available in 8ft (2400mm) x 4ft (1220mm) sheets from the lumber mill square.
The edges are usually square but can be easily machined to provide a tongue and groove interlocking board when used for flooring
MDF comes in a wide range of thicknesses ranging from ⅛” (3mm) up to 1.0” (25mm), the thicker sheets provide the strength needed when used as a flooring material.
MDF is a high-quality product and is generally more expensive than chipboard and it is often cheaper to buy than the equivalent plywood.
There are several grades of MDF available including moisture resistance and fire retardant this along with how easy it is to cut or machines makes MDF a versatile and much-used product.
Please note, that when cutting or machining any of these man-made products, you should always use personal protective equipment especially an appropriate/suitable face mask to prevent inhaling any dust or fibers which can cause health issues.
Always check health and safety guidelines for up-to-date advice.
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This article was written by: Richard Quinton – The DIY Help Desk Owner, Engineer & technical specialist.
Richard is one of the key partners in The DIY Help Desk team. He is a qualified Engineer, writer, and publisher, educated to Master’s level. He is a keen advocate of DIY and home improvements.
Richard enjoys helping others to learn new skills and reach their goals and believes that passing his knowledge and experience on through his writing is an effective way to positively impact the lifestyles and well-being of others on a larger scale.
