Why do Palace Planks come in so many different widths?

A quality tight friction fit is essential to achieve a quality insulation standard by preventing cool damp underfloor air moving around the insulation product and coming in direct contact with the floorboards. Palace Planks are cut oversize and the concertina edge cuts allow the polystyrene to be squeezed to fit securely between the timber floor joists, with the polystyrene pushing firmly and neatly against the timber joists along its entire length.

Cutting off a single 15mm concertina with a fine tooth saw provides an intermediate size. Other manufacturers with a limited size range recommend cutting off multiple concertinas with a box cutter. A box cutter will not necessarily create the clean parallel edge  needed to seat firmly against the joist along the planks entire length, and when too many concertinas are removed insufficient concertinas remain to provide a quality friction fit and installation quality suffers.

In the development of the current Palace Plank range we rigorously researched and tested the concertina cut approach to friction fitting polystyrene. Concertina cutting was first suggested in the 1970's by BASF who manufacture the raw material for polystyrene manufacturers. Rmax in Australia were first to market in Australasia with concertina cut polystyrene panels.  

Some NZ manufacturers products have concertina cuts that are too deep and as a result the concertinas fail to provide the optimum reactive force over the full range of fit, while concertina cuts in other NZ manufacturers products don't even overlap so the products are rigid to the extent that friction fit is more of a marketing statement than an achievable installation technique. 

The number of D.I.Y. installations that fail EECA's insulations standards demonstrate that care must be taken to achieve a quality gap free installation. Poly Palace has the highest performing polystyrene products on the market, and we expect that a similar focus on quality is maintained in our products installation.

Poly Palace wide range of plank widths are set in 25mm steps to match the imperial inch measurements often used by the builders of houses built before the metric system was introduced. These sizes coincidentally match the common joist spaces in modern homes that use slightly narrower dressed timbers at regular metric spacings. 

Palace Planks sizes are colour coded to make matching of Palace Planks to joist spaces simple. In the often cramped and dimly lit under-floor crawl space, using a imperial measure tape allows installers to choose the correct colour coded plank size at a glance.

Poly Palace's wide range of colour coded sizes means a quicker, higher quality installation with less cutting and less waste. Whilst Poly Palace recycle all waste we prefer our products to end up in YOUR home not our recycle bins. Poly Palace's policy of continual refinement has resulted in the today's range of Palace Planks in sizes and quality of friction fit unmatched by our competitors.