50mm Polystyrene Insulation

About

50mm polystyrene insulation boards are one of the most widely specified thicknesses across UK construction, and it is not difficult to see why. Thick enough to deliver meaningful thermal performance as a standalone layer in a wide range of floor, roof, and below-ground applications, yet practical and straightforward to handle and cut on site, 50mm sits at a point where performance and usability meet. Polystyrene insulation sheets at this thickness are regularly specified below ground-floor slabs, within screed and chipboard floor build-ups, in inverted and flat roof applications, and wherever superior moisture resistance or high compressive strength is required. For the applications they are designed for, 50mm polystyrene insulation boards perform reliably and consistently. Whilst polystyrene does not offer the same thermal conductivity as PIR or phenolic, it delivers strong performance relative to its cost, with good compressive strength and solid moisture resistance that makes it a trusted specification across both domestic and commercial projects. The U-value achieved will always depend on the full build-up rather than the board alone, but at 50mm polystyrene boards make a meaningful contribution to thermal performance across all the applications covered by this range. Types of 50mm Polystyrene Insulation EPS boards are available in standard white EPS, high performance graphite-enhanced grey EPS, and specialist clay heave boards, covering everything from standard domestic floor slabs through to foundation protection on clay-heavy ground. Browse the full EPS range on our EPS insulation page. XPS boards from Kingspan GreenGuard and Ravatherm offer superior compressive strength and moisture resistance, suited to below-ground, inverted roof, and moisture-exposed applications. Browse the full XPS range on our XPS insulation page. Applications for 50mm Polystyrene Insulation Boards Floor insulation is the most common application for 50mm polystyrene insulation boards.