The bituminous membrane MULTIGUM is an elastoplastomeric waterproofing membrane obtained from distilled asphalt modified with thermoplastic resins (APP, IPP). The membrane is reinforced by a non –woven polyester (P), or glass fiber tissue (V). The upper surface of the membrane is protected by slate flakes (Μ) in various colours such as natural grey, white, red, green or by talc (Τ). Alternative quartz sand or polyethylene film can be used.
The lower surface of the membrane MULTIGUM is protected by a plastic film easily torched.
An overlapping side strip of 10 cm is left free from slates and is covered by a plastic film which is torched to weld the joints.
PHYSICAL AND CHEMICAL CHARACTERISTICS
- very good low and high temperature resistance
- very good resistance to ultraviolet radiation
- absolute watertightness
- good resistance to acids and alkalis
- very good tensile strength and elongation
- tear resistant
- resistant to static loading
Glass fibre tissue
- excellent dimensional stability
- excellent protection from ultraviolet rays
- increases the ageing resistance
- reduces the spread of flame in case of fire
The roll dimensions are 10m long and 1m wide (other rolls dimensions are available on request).The rolls are supplied on wooden pallets and are held in position by a heat shrunk plastic bag.
INSTRUCTIONS FOR USE
The surface must be smooth, clean and dry, free from dust, oils grease and other debris.
The surface is then treated with bituminous primer (EXTRALAC PRIMER at a consumption of 0.2-0.25 kg/m²) or with elastomeric bituminous primer (ELASTOLAC at a consumption of 0.3-06 kg/m²) and allowed to dry at least for 24 h before the application of the membrane.
In alternative can be used bituminous emulsion EXTRACOAT at a consumption of 0.5-1 Kg/m² or EXTRACOAT RUBBER at a consumption of 0.5-1 kg/m².
The membrane is unrolled on the dry primer coating and aligned before it is rolled back.
The membrane is unrolled again while the lower surface is heated and especially the primer by means of a propane gas torch, until the polyethylene film starts to melt, ensuring the adhesion of the membrane to the substrate.
Side laps must be at least 10 cm and end laps 15 cm. When the bonding of the roll is completed we torch the overlaps taking care not to weaken them by extreme heating and by means of a trowel we press to achieve good bonding.If we want to strengthen up the overlaps or other sensitive points on the roof (ventilators, drains, upstands etc), we can apply bituminous sealants Masticgum No1 or Masticgum No2 (for horizontal or vertical surfaces respectively )which should prodect from sun radiation with one or more layers of bituminous aluminium paint ALUCOAT.
In a multi layer system the first layer can be applied as loose laid, partially attached or fully adhered. The subsequent layers must always be fully adhered.
During the application care must be taken so that the overlaps of the subsequent layers to not coincide with the overlaps of the previous layer.