Paro-Melt® System

A vapour permeable layer, lapped and sealed, is installed over the insulation to restrict the flow of water in an inverted roof system. This reduces the ‘cooling effect’ of rainwater on the insulation, reducing the correction values required in thermal calculations for insulation on inverted roofs in turn reducing insulation thicknesses. The WFRL also acts as a filter to prevent small fines or particles being washed in between and below the insulation, potentially damaging the waterproofing or blocking drainage.

Thermal insulation is an essential component within any inverted warm roof system. Its purpose is to control and maintain the temperature of the building below. It’s important to ensure a sufficient thickness of insulation is installed in order to meet the requirements of the appropriate Building Regulations and local legislation. Other considerations are critical when selecting the type of material used as a thermal insulant, especially when used in an inverted application are, its suitability certified in inverted applications where it is above the primary waterproofing layer and exposed to the passage of rainwater through the roof. In addition, due to the additional weight of ballast that will be imposed on the roofing system and the likelihood of increased levels of pedestrian access and foot traffic, the compressive strength and loading capacity of the insulation must also be checked. Fire performance and overall compatibility with the waterproofing system is also a key consideration when selecting the insulation.

The Paro-Melt® Protection Membrane is a polyester reinforced, SBS elastomeric modified bituminous waterproofing membrane with anti-root additive, finished on both upper and lower surfaces with fine sand to aid full adhesion into the Paro-Melt® Hot Melt Compound. The protection membrane is rolled into the Paro-Melt® Hot Melt Compound in a pour and roll application method.

Paro-Melt® Hot Melt is an elastomeric polymer modified bitumen mastic, designed for use as the structural waterproofing compound in a hot melt waterproofing system. The compound is heated and applied in a poured application simultaneously with Moy’s distinctive blue Paro-Melt® Reinforcement Mesh, immersing the specially designed glass-fibre fabric mesh. This governs the amount of compound and its flow rate to ensure an even and consistent coverage rate, maintaining the specified film thickness of the waterproofing.

Paro-Melt® Hot Melt Primer will be required over the roof deck, prior to the application of the Paro-Melt® waterproofing system to ensure full adhesion to the substrate is achieved.

The structural roof deck spans the structural frame of the building to provide a continuous support for the roofing system and ultimately what the roof is attached to. For inverted hot melt applications, due to imposed loadings for such roofs, this will usually be in the form of pre-cast concrete or in situ concrete cast over a profiled steel liner. It is critical the deck is designed to accommodate the additional design loadings expected of this roof type.