One of the most common questions we get asked from clients is ‘Do we need levelling’, and the information in the market place around this topic is very confusing, to say the least. All timber flooring products have minimum standards required for the flatness of the subfloor that applies in order to maintain a warranty. The difficulty in interpreting these standards is:
• The difference between levelling and flatness is not always understood;
• Different products (that are often very similar) can have different install requirements;
• The same products can have different requirements based on the installation method.
So what is flat and what is level? Flat refers to deviations in the subfloor that affect the smoothness. A good example is a driveway. A driveway can be very flat, but still unlevel if it goes up or down a slope. Level refers to all points being at the same height – think of the surface of a pool of water. Of course, if something is Level it also means it is flat, but being Flat is actually what is required by flooring products – the level is not relevant in most instances.
The diagrams below show how these two separate measurements are checked. The first diagram shows a check for levels, with the second two showing checks for flatness.
As a general guide (and all individual manufacturers can have different requirements) the following usually apply:
Hybrid/vinyl products – 4mm over 2m lengths (with tighter controls over smaller irregularities like grout lines in tiles)
Laminate (Floating install) – 4mm over 2m
Engineered (Floating Install) – 4mm over 2m
Engineered (Glue Down) – 2mm over 2m
Engineered (Nail down) – 5mm over 2m
Solid (Nail down) – 5mm over 2m
Parquetry (Glue Down) – 2mm over 2m
As mentioned, each supplier of materials have their own specifications for the flatness of subfloors, however, we find that the above guides match (or a reasonably close) to most on the market today. Our team of professional project managers will walk you through these requirements, along with all other technical aspects of your flooring choices. We also try to establish the cost and time required to complete these preparation works early on – there is nothing more frustrating than having costly add-ons presented after you thought the budget was decided.
The most important thing though is that getting subfloor preparation right is not just about maintaining a warranty – it is the single biggest factor that will influence the performance of your floor – regardless of the product choice.
So drop into one of our showrooms today and get talking to our team – levelling (or flatness!) isn’t something to be afraid of when dealing with professionals.