What Is Engineered Oak Flooring?
Traditionally, oak flooring is made by processing an oak tree into wide slices approximately 100mm thick.
These layered planks are allowed to season over a number of months or years and are, in some cases, then kiln dried.
The layers are sliced again to form thinner board blanks (around 25mm thick) which are then planned, cut and grooved to form finished solid oak floor boards.
Engineered flooring follows the same process but instead of the finished floor boards being 20mm thick, a thinner veneer is cut, between 4mm and 6mm thick.
This oak veneer is then bonded to a softwood ply board, taking the thickness of the finished board back up to around 20mm.
This process is great from an environmental point of view, as more floor boards are created from the same tree, and the bulk of the board is made up of wood from fast growing, sustainable softwood trees.
Where & Why To Use Engineered Oak Flooring
The inherent advantages of engineered oak flooring stem from the marrying of a hardwood wear layer to a softwood ply backing board.
Solid oak has a natural tendency to change shape when its moisture content changes – shrinking when it dries and swelling when it gets damp.
Ply board is made by bonding strips of softwood in layers with each layer being perpendicular to the previous layer.
This gives incredible strength and torsional rigidity i.e. it does not change shape as readily as a solid wood plank.
By bonding the hard wearing and attractive oak veneer or wear layer to the dimensionally stable plywood base, the resulting board is strong, stable and looks great.
Engineered flooring is then ideal for use where moisture may present problems such as in kitchens and bathrooms, but is also ideal for where a constant drying may take place such as over underfloor heating systems.
The negligible expansion and contraction of this flooring also lends it to being glued to a subfloor rather than nailed and allows for wider boards to be glued than possible with solid oak flooring.
What To Look For When Buying Engineered Oak Flooring
In most cases, an oak floor is selected based on its appearance.
If you are aspiring to a traditional looking oak floor, you will need the oak boards to display the character of a classic solid oak floor.
For this reason, it is important that any knots, shakes, or cracks in the oak are left unfilled.
Sadly, much engineered oak on the market is ruined by the filling of naturally occurring features with plastic polymers and resins, which although they smooth out the floor, render it unattractive and unnatural.
They key elements to consider when choosing an engineered oak floor are:
Is the softwood ply board backing of good quality – is it even and dense with few splinters, dents and missing strips?
Is the oak wear layer thick enough (it should be at least 6mm thick) to allow sanding at least three times in the future, should fashions change and the floor colour need to change with them?
Are the boards grain end matched to allow for longer runs of board?
Are the boards available in lengths over 1800mm?
Is the flooring supplied with a polyurethane coating or left unfinished for you to decide on the colour and finish?
Choosing an oak floor is an investment and buying the cheapest available is not necessarily the best way to go.
How To Lay Engineered Oak Flooring
Engineered oak flooring can be laid in one of two ways: traditional hidden nail/screw or by gluing using a wood floor adhesive.
The decision as to which method to employ tends to be based on factors such as room heights, levels of adjacent floors and the nature and state of the subfloor.
Engineered boards lend themselves very well to gluing because of their inherent stability and where a floor is required to be laid over under floor heating, a glue based system is essential.
The engineered boards should be tongue and grooved and so, if fixing to battens or a wooden sub-floor, the boards can be secret nailed or screwed through the tongues.
Engineered oak is an increasingly popular choice when it comes to flooring and offers a range of advantages over solid oak both form an environmental and practical point of view.