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Newton 106 Flexproof - Flexible Polymer Waterproofing Compound 15kg

£297.00 Ex VAT
£356.40 Inc VAT

Waterproof joints with this durable and highly flexible liquid waterproofing coating from Newton - ideal for when building movement is expected.

Flexible liquid waterproofing coating for joint waterproofing 

Newton 106 FlexProof is a very flexible waterproofing compound for the waterproofing of joints.

FlexProof is capable of resisting both negative side and positive side water-pressure at construction joints. This is still the case even where severe movements are expected thanks to very high levels of flexibility. FlexProof bonds extremely well with most substrates and becomes rainproof in minutes.

FlexProof comes in two variants:

  • Newton 106 FlexProof-X1 - for waterproofing of construction and vertical movement joints
  • Newton 106 FlexProof-NV - pourable so better suited for horizontal movement joints. 

Uses of FlexProof 106

FlexProof 106 is suitable for both static construction joints in poured concrete retained structures as well as non-static construction joints to precast concrete elements within retained structures.

It is ideal for the following:

  • Waterproofing of construction and movement joints
  • Flexible sealing mastic
  • Waterproofing of joints between substrates subject to differential movement
  • Detailing to Newton HydroBond System

And can be used on the following substrates:

  • Concrete of at least 20 kN
  • Concrete block walls with flush pointing
  • Screed
  • Metal
  • Plastics
  • Timber
  • Glass

Applying Newton 106 FlexProof

Newton 106 FlexProof is easy to apply. FlexProof NV can be poured straight from the bag with no mixing whereas X1 will require a cartridge gun.

 You will also require the following tools:

  • Metal trowel
  • Metal putty knife
  • Brush - for detailing


Newton 106 FlexProof-X1 should be applied over construction joints in bands of 300mm wide with the joint being central to the application.

Start by marking out the application area with tape - this helps with neatness. Next you should open the bucket and remove the 15kg foil bag. Cut a 100mm corner from the bag and pour the product out of the bag.

You should now use a trowel to spread the product to a uniform thickness of 2.5mm. Remember to create a band of 150 mm either side of the construction joint. When the liquid waterproofing has cured, you can remove the tape edges. Use a trowel to finish.

Note: When waterproofing a negative pressure side, or to reinforce any joint or at changes in direction, bed Newton FlexProof Scrim into the still tacky FlexProof-X1 and tamp in with the edge of a trowel until covered by the product.


Carefully insert the correctly sized Newton FoamStop into the joint using a blunt chisel and a hammer.

Do not damage the Newton FoamStop. Ends of the FoamStop should be butted - no adhesive joint of the butted ends is required. Mitre at changes in direction. (see technical data sheet)

Apply tape to both sides of the joint. This defines the area and ensures neatness of application.

Newton FlexProof can be either poured directly from the foil bag packaging or gunned from a cartridge with a mastic gun.

The method of application is dependent on the size of the movement joint. For narrower joints, use Newton 106 FlexProof-X1 cartridges. Alternatively, decant the product from the foil bag into an empty mastic gun cartridge and gun the product into the joint.

  • Foil bag - Joints of 18-72 mm
  • Cartridges - Joints of 5-18 mm

Open the bucket and remove the foil bag. Cut the corner off the bag to a size that is suitable for the width of the joint.

Pour sufficient product from the foil bag directly into the joint above the Newton FoamStop to the correct depth. A soapy wet knife can be used to smooth if required.

Permagard - Providing Solutions. Inspiring Confidence.

Permagard are proud to stock a wide range of Newton membranes and waterproofing products. If you have any questions about Newton FlexProof or waterproofing construction joints in general please call our team on 0117 982 3282. 


  • No mixing required – simply open the packaging and use.
  • Part of the Newton HydroBond System
  • Suitable for use in sub zero temperatures and on slightly damp substrates
  • No primer required
  • 100% waterproof, but allows vapour diffusion.
  • Highly flexible – can cope with movement and fissures in substrate.
  • Excellent adhesion to suitable substrates
  • Resistant to temperature variations maintaining its characteristics between -40ºC & 90ºC.
  • Excellent resistance to the high alkalinity of concrete