From £326.30 + VAT per 1.5 x 50m roll.

Moisture barrier membrane for swimming pools and saunas – Ampatex Sisalex 518

Ampatex Sisalex 518 moisture barrier membrane is:-

  • extremely moisture and chlorine resistant, making it ideal for swimming pools and saunas.
  • a highly tear resistant fleece backed membrane, with an Sd value of more than 1500m.
  • perfect for ensuring the correct moisture flow through building structures using vapour open and vapour closed insulation materials.
  • an easy to use membrane for providing a continuous internal air tightness layer.

Product overview

Where is it used?

  • On the inside of timber/metal frames/dry lining, on the inside of roof structures or on the top side of floors.
  • Can be used as a moisture barrier (DPM) in basement walls and floors.

How is it used?

  • Sisalex 518 moisture barrier membrane should always be used on the warm side of the wall/roof and with the writing facing inwards.
  • It can be bonded, using Ampacoll DT double sided tape, to the underside of rafters or the inside of timber studs prior to being boarded over or counter battened.
  • If using on the inside surface of wood fibre insulation boards, apply Ampacoll Primax primer and Ampacoll DT double sided tape to the surface at regular intervals to allow the membrane to be bonded to the surface.
  • When used in saunas or swimming pools, joints should be sealed with Ampacoll BK530 double sided tape first and then Ampacoll Flexx Pro airtightness tape.
  • All joints should overlap by at least 100mm and the perimeter should be sealed prior to counter battening or being over boarded with plaster board.
  • Once the joints are taped it forms an air tight, moisture regulating layer.
  • Any penetrations, such as joists, pipes, cables or ducts should be sealed with Ampacoll BK 535 penetration sealing tape.

How much will you need?

Each roll of Sisalex 518 moisture barrier membrane is 50m long and 1.5m wide. It covers an area of 70m2 accounting for overlaps.

Frequently asked questions

Do I need to tape the joints?

Yes, you should always tape the laps, usually with the Ampacoll INT or the XT tape. This ensures the air tightness of the membrane and that it functions correctly to reduce moisture flow through the walls from the interior. If using in swimming pools or saunas you should also seal the laps with Ampacoll BK530 double sided tape.

What are its properties?

  • The Sd value of the membrane is more than 1500m which is very high and so is classified as a moisture barrier membrane rather than a vapour control membrane. However, it makes it ideal when building swimming pools and saunas as it prevents the very high moisture levels of moisture inside the building damaging the fabric.
  • Sisalex 518 is also waterproof so can be used as a DPM for damp proofing basement floors and walls.
  • It has good tear resistance, 180N/5cm

Pricing & shipping

This product is on a 1.5m long roll and will be sent by courier, costing around £20 + VAT

Roll length [m]Roll width [m]Roll Area [m²]Membrane weight [g/m²]Roll weight [kg]Sd value [m]Single roll cost [£]3+ rolls [each]

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