Dimensional stability – The core of the problem

by Tania Wannenburg
Subfloor Jnl1.14

Within a relatively short period of time, a number of Luxury Vinyl Tile (LVT) installations have failed. Even when the contractor has installed the tiles according to the manufacturer’s specification, peaking and gapping still occurs.

The culprit is less complex than one might think – simply insufficient (or lack of) “dimensional stability” which is undoubtedly the most crucial element in the construction of LVT.

As with any floorcovering, LVTs are exposed to extreme changes in subfloor and internal temperatures which will affect the performance of the flooring. The majority of LVTs produced will conform to the European Standard for dimensional stability – EN434 – the minimum norm : <0.25%. The question is – is this sufficient?

The challenge

If the plank is 200mm wide and it expands at 0.25% (0,5mm per plank) over an area of just 15 planks (3,00m wide room), the total expansion will be 7,5mm. If the plank length is 1 200mm and the plank expands at 0,25% (3mm per plank), the total expansion will be 12mm over just 4 planks in a 4,80m long room.

The problem

The 5mm expansion gap, as recommended by most LVT suppliers, is not sufficient in an area larger than the above example!! The larger the application the more excessive the plank movement – thus the problem is multiplied.

The result

Peaking, curling and/or gapping particularly in areas of direct/indirect sunlight. This inevitably leads to product failure.

The solution is to ensure that the LVT that is specified (or the one that is recommended to the client or designer) has sufficient dimensional stability; otherwise you may be heading for a costly product failure and an unhappy customer.

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