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Guides to installing underfloor heating

How Much Adhesive Do I Need?

Whether you're embarking on a DIY home improvement endeavour or a professional construction project, getting the right quantity of adhesive or self levelling compound is crucial for achieving a successful and lasting outcome.

In this guide, we'll walk you through the key factors to consider, provide handy tips, and offer a convenient calculation to ensure that you have just the right amount of adhesive or leveller to get the job done seamlessly.

How much adhesive do I need?

Using the formula of 1.8 kgs per 1mm depth per m2, it's recommended to provide a minimum 3mm bed of adhesive for securely attaching the XPS insulation boards or BACKER-PRO tile backer boards to the sub-floor. Additionally, you should account for a 4mm coverage for the cable and an additional minimum 1.5mm bed of adhesive to ensure effective tile bonding. This results in a combined adhesive depth of 8.5mm.

  • 5m2 tiled area with insulation board

    5m x 8.5mm x 1.8kg = 77kg

    Total amount of adhesive

    5m2 tiled area with insulation board

    = 4 x 20kg bags

  • 10m2 tiled area with insulation board

    10m x 8.5mm x 1.8kg = 153kg

    Total amount of adhesive

    5m2 tiled area with insulation board

    = 8 x 20kg bags

How much self levelling compound do I need?

Using the calculation of 1.8 kilograms per 1mm depth per square meter, it's essential to allocate a minimum 3mm layer of adhesive for securely attaching the XPS insulation boards or BACKER-PRO tile backer boards to the sub-floor. Additionally, consider a 4mm coverage for the cable and an added minimum of 1.5mm adhesive depth for effective tile bonding. This results in a total adhesive depth of 8.5mm.

  • Based on the formula

    1.67Kg/sqm x area(sqm)

    x 6mm thickness divided by 20Kg

    = number of bags

  • Example for a 5m2 area

    1.67kg x 5m x 6mm = 50kg

    Total amount of levelling compound

    = 3 x 20kg bags

  • 5m2 tiled area with insulation board

    1.67kg x 10m x 6mm = 100kg

    Total amount of levelling compound

    = 5 x 20kg bags