
Heartwood Flooring Explained
PRODUCT
- What is engineered hardwood flooring?
- What are the benefits of engineered hardwood over laminate and solid hardwood floor?
- How many layers does engineered flooring have?
- What is the thickness of the hardwood veneer?
- What does greater stability mean?
- What is the moisture content of the floor boards?
- What is the lock system of the engineered hardwood floors?
- What does it mean when engineered hardwood is sold in random lengths?
- How are hardwood planks supplied?
- Difference between European Oak and American Oak?
- Does engineering destroy the natural beauty of hardwood floors?
What is engineered hardwood flooring?
Engineered hardwood flooring is a product made up of a core of hardwood, plywood or HDF and a top layer of hardwood veneer that is glued on the top surface of the core and is available in almost any hardwood species. The product thus has the natural characteristics of the selected wood species as opposed to a photographic layer. The “engineered” product has been designed to provide greater stability, particularly where moisture or heat pose problems for solid hardwood floors.

What are the benefits of engineered hardwood over laminate and solid hardwood floor?
Engineered hardwood is more versatile and stable than solid hardwood and laminate; more resistant to moisture and humidity than solid hardwood. It is also better for basements, where dampness is common; able to be installed over underfloor heating systems, which tend to dry out solid hardwood causing the boards to shrink, cup and buckle. It is also suitable to be laid on concrete floors, either as a direct glue-down or as a floating floor system.
How many layers does engineered flooring have?
In addition to the top hardwood veneer, engineered wood flooring typically has three or more layers. Generally, there is greater stability with more layers. The core layers and back could be made up various wood species. Heartwood boards have either a Birch or Spruce core layer
What is the thickness of the hardwood veneer?
The hardwood veneer, top layer hardwood, can typically be 4-6mm dependant on the plank width. A quality hardwood veneer will provide many years of wear.
What does greater stability mean?
The instability of solid hardwood is usually moisture or heat related. Under adverse conditions, solid hardwood floors can warp, cup, swell or split apart. Engineered hardwood flooring overcomes these problems by constructing a multiple-ply plank which counteracts twisting and remains flat and intact. This makes engineered hardwood flooring a better choice for installation on floors with underfloor heating.

What is the lock system of the engineered hardwood floors?
4 sided Tongue and Groove lock system.

What does it mean when engineered hardwood is sold in random lengths?
Lengths will vary from manufacturer to manufacturer. Some will include boards of all one length, generally at a higher cost because of the length consistency required. Heartwood Flooring boards are supplied with a maximum of 10% short boards allowed with a minimum of 600mm in length.
How are hardwood planks supplied?
The planks are supplied unfinished and lightly sanded or as finished boards in predetermined colours. The boards will have a 0.5mm micro bevel on the long sides with square edges on the short sides. The knots are filled with a brown filler (please consult the grade selection for further technical information).
Difference between European / French Oak and American Oak?
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- Species and Origin
European Oak relates to a hardwood native to most of Europe and is, in fact, the same species as English Oak. American Oak is also related to a hardwood predominantly found in Eastern North America. Both species are classed as “white” oaks and have been known to live for several hundred years. We source our European & French Oak from sustainably managed forests in Europe. - Colour Tone
Although both oaks are similar in tone, European & French Oak generally tends to be a little darker than American Oak. European & French Oak is a warm golden, honey colour whereas American Oak is subtly lighter with pinkish tones. - Variation in Tone
As timber is a natural product the tone varies from board to board (this is the beauty of a natural solid oak floor). On the whole European & French Oak has a more even colour tone from board to board than American Oak which can show greater differences between light and dark shades. - Grain Pattern
European & French Oak tends to have a distinctive, wavy grain pattern with scatterings of pip and burr. American Oak tends to have a straighter, subtle grain pattern. - Fuming
This is a chemical process whereby the timber is darkened by applying ammonia, as a gas, in a sealed chamber. European & French Oak fumes very well, giving a lovely rich, dark, almost walnut colour (this is also done with stains).
- Species and Origin

Does engineering destroy the natural beauty of hardwood floors?
Not at all. The top hardwood layer (a hardwood veneer) is the same genuine hardwood you have in solid hardwood floors.
What is the Janka hardness test and why should I be aware of it as a consumer?
As a consumer of quality wood flooring, you naturally want to know how the product you are thinking about purchasing will withstand wearing and dents. The Janka hardness rating is your standard measurement for this purpose. The Janka test is conducted by measuring the force needed to lodge a 15mm steel ball in the wood species to a depth of half the ball’s diameter. The higher the rating, the harder is the species of wood.

Is there a benchmark for comparing the relative hardness of other wood?
White Oak is a very popular, durable species. It has a Janka rating of 1360 and serves as a benchmark for comparing the relative hardness of other wood species.
Is the Janka rating useful for engineered hardwood flooring?
The Janka rating is a good one to keep in mind for engineered hardwood flooring as well as solid hardwood, especially if durability is a key selling feature for you. The Janka hardness rating of the hardwood used for the veneer on your engineered flooring will guide you to the best choice for your intended flooring use.

What is the content of formaldehyde in your woods board?
According to the law, companies cannot sell products whose equilibrium concentration of formaldehyde exceeds a value of (0.1 ppm) or (0.124 mg/m³) or (E1 is ≤1.5mg/L), which corresponds to the limit set for class E1. Our supplier uses phenolic glue with a formaldehyde content of 0.35mg/L.
How should I install my engineered hardwood?
Engineered flooring can be installed in three different ways:
NAIL DOWN – ideally a timber batten framework needs to be constructed and a moisture barrier placed below.
GLUE DOWN – over plywood concrete subfloor or stable tiled floor . If gluing the floor directly on the subfloor, use an adhesive with an integrated vapour barrier.
FLOATING – over plywood or concrete subfloor or stable tiled floor .For float installation, use an underlay with a vapour barrier. Usually for floating, the seams will still need to be glued together using regular wood glue, unless the specific engineered floor is a glue-less click-lock.
Please note that the explanation above is a general guide. Please refer to your installer for details.
Can I lay engineered wood on top of tiles?
This can be done quite easily in many cases. The tiled floor must be stable and secure and relatively flat with no loose pieces. Floating is rarely a problem and glue-down can work. A good floor wash, followed by a rough sand are a must. Some of the high gloss ceramic tiles cannot be glued onto. The installer would need to conduct an adhesion test to check.

What is the process of staining and sealing and what is the time frame?
An onsite sand and seal is a timeous process and in larger installations, it would be necessary for the client to vacate the areas that are being done ( if they are living in the house). A typical family home would need about 1 week, followed by a few days curing time.
Most water-based varnished take up to 7 days to reach full cure, but can take light foot traffic after 24-36hrs. Oils are generally quicker, but have more odours compared to water-based varnishes.
There are 2 main classes of sealants for timber floors:
Varnish Polyurethane
Varnish is typically available in different wear classes; Residential, light commercial and heavy duty. Varnish or Polyurethane is a low maintenance finish and most appropriate to typically South African use. Modern water-based varnishes are very eco-friendly and non-toxic. We prefer Bona, which meets all EU requirements, as well as Green Star and Leeds specifications. Cheaper varnishes tend to skip on the expensive raw materials and are thus prone to yellowing very quickly and have limited wear ability.
Oils
Although oils are deemed to be able to handle more robust usage, they require ongoing maintenance. Oils are very popular in Europe, but do require much more maintenance to keep looking good. An easy way to explain this is the oiled floors are appropriate if the client removes their shoes at the front door and can control all fluids on the floor (i.e. NO dogs or pre-school kids in the house)
The Handover procedure
Once the floor is installed and finished the floor should be covered with a temporary protection. Skirtings and doors will need to be fitted after this, and then followed by a final paint application. The new floor will get damaged if it is not protected during this process. Once the site is ready, the protection can be removed and the floor washed and commissioned, i.e. inspected to ensure it meets the specification and the approval of the client.
Can I refinish (sand) an engineered floor?
It depends upon the thickness of your hardwood layer. With the high quality finishes that are offered and the extensive process that refinishing a floor entails, damaged areas are often removed professionally. If sanding is desired, the professional sanding procedure removes 0.8mm each time.