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Toughseal - Data Sheet

Toughseal is a solvent free polymer modified epoxide coating, supplied as a two part pack of base and hardener in premeasured proportions. 


  • Water and water vapour barrier
  • Abrasion resistant
  • High substrate adhesion
  • Chemically resistant
  • Class 1 Fire rating
  • U.V. resistant


  • Ground floors
  • Computer floors
  • Plant rooms and Bunded Areas
  • Basement and Sub-structures
  • Superstructures
  • Swimming pool / wet rooms and other wet areas


  • Concrete
  • Masonry
  • Steel

Typical uses

Toughseal is typically used to provide a water and water vapour proof barrier, or to give protection against abrasion, fresh and salt water, carbon dioxide, alkalis and dilute mineral acids. It is resistant to U.V. light and atmospheric attack but should perhaps not be used where aesthetics are important. Suitable uses for Toughseal include, raised access floors, ground floor slabs, swimming pool wet areas and shower areas, plant rooms, sewage plants and marine applications. When dressed with a suitable aggregate it will provide a slip retardant wearing surface or a waterproof key for tile bedding or renders. The coating can be used to protect iron and steel against corrosion and concrete against carbonation. Toughseal should not be used in contact with potable water systems.


Subject to normal conditions of use Toughseal, when covered, will provide an effective barrier to the transmission of liquid water and water vapour for the life of the structure. 


J30 - Liquid Applied Tanking/Damp Proofing in accordance with NBS Clauses. Please consult RIW for further information.

Independent Authority

Toughseal has been tested in accordance with BS 476: Part 7: 1997, “Fire tests on building materials and structures, method for classification of the surface spread of flame of products”, and is Classified as Class 1.


Cementfill FC- Cement based waterproof fairing coat and repair mortar for filling minor holes, voids and defects.

Cementfill HB- Cement based waterproof high build repair mortar for profiling and providing fillets.

Aggregate, Grade 1- a coarse grit to provide a ‘key’ for following wet trades, such as tiling or rendering.

Aggregate, Grade 2- a fine grit to provide a ‘slipretardant’ finished surface.

Cleaning Solvent- a liquid for cleaning tools, equipment, etc. (must not be used as ‘thinners’)

Flexiseal- a flexible liquid applied membrane for use over Toughseal when reinforcing joints etc - see separate data sheet.

Toughseal Reinforcement Tape- a tape for use over Toughseal when reinforcing joints etc internally, prior to tiling.


All construction should conform with the Building Regulations, Codes of Practice and British Standards in current use at the time the building is being constructed. In particular, it is recommended that reference is made to BS 8102:2009.


All surfaces: Should be smooth, clean, dry (to a depth of 1-2mm), sound and free from frost, oil, grease, condensation and other contamination. Any voids or hollows must be made good to a flush finish with a suitable filler. Any sharp edges or high points should be eliminated. External corners should be chamfered or rounded where required, to assist application.

Concrete surfaces: Horizontal surfaces should preferably be smooth, however lightly tamped (3-4 mm peak to trough profile), brushed or floated surfaces may also be acceptable. Surface laitance should be removed by suitable means where neccessary.

Masonry: Should be sound with joints flush pointed or ‘bagged out’ with Cementfill or similar before the membrane is applied. Open textured surfaces should be sealed with Cementfill FC or a sand/cement slurry to provide a suitable surface. If existing surfaces are very rough, they may require rendering.

Metal Surfaces: Should be wire brushed or sand blasted, and pre-treated with a steel primer, prior to application of the membrane. Corroded metal should also be treated with an anti-corrosive primer. Toughseal is compatible with all commonly encountered steel primers, including alkyd, chlorinated rubber and epoxy based materials. Consult RIW for galvanised steel and/or other treatments.


General: Application of Toughseal should not be attempted in temperatures below 5°C. Toughseal should not be thinned and should be applied as supplied. The base component of Toughseal should be mechanically stirred for 3 minutes, and then the hardener component added and mixed thoroughly until a uniform colour is achieved. Do not split base or hardener components. Toughseal should be applied immediately after mixing. Apply in two coats at a minimum application rate of 4m2 /litre per coat. Good ventilation is necessary to obtain a proper cure. At 20°C, Toughseal will require 6 hours minimum before overcoating. Curing will stop at temperatures below 5°C. The second coat should be applied within seven (7) days of the first, if this is not possible advice should be sought from the RIW Technical Department. Reinforcement at angles, joints, pipes etc, should be carried out using Flexiseal, over the Toughseal at a rate of 1m2 /kg (within seven days of application) or Toughseal Reinforcement Tape, as appropriate.

Manual: Toughseal should be applied using a stiff brush or medium pile roller.

Spray: For details of specialist applicators, please consult the Technical Department.

FormTwo part epoxy coating
ColourBlack or Grey
Specific Gravity1.15g/ml (mixed product) 
Solids content100% (w/w)
Flash Point

200˚C (Base)

130˚C (Hardener)

Water vapour transmission rate
ASTM D1653

Black - 2.41 g/m2 /24 hr

Grey - 2.25 g/m2 /24hr

Water vapour permeability ASTM D1653

Black - 0.1144 g//m2 /24hr/mmHg

Grey - 0.1068 g/m2 / 24hr/mmHg

Coverage*4m2 /litre/coat
Number of coatsTwo
DFT of coating0.50mm for two coats
Curing timeTouch dry: 6 hours min 7 days (full chemical resistance)
Overcoating timeMinimum: when touch dry Maximum: 7 days
Application temperature limits5-35˚C
Preparation of liquidStir well by mechanical means
Pot life20 mins at 20˚ C
Shelf life (Temperate climate)12 months
U.V. LightHigh
Heat (Dry)130˚C
Heat (in water)80˚C
White spirit/ Diesel/PetrolResistant
10% Sulphuric acidResistant
10% Nitric acidResistant
10% Hydrochloric acidResistant
Ammonia solutionResistant
50% Sodium hydroxideResistant

Further details on resistance to immersion, and on other chemicals, is available from the RIW Technical Department. The above performance figures are typical and should not be considered a product specification. *Figures quoted are theoretical coverage areas. Actual coverage may vary depending on nature of substrate.


Plant Rooms & Wearing Surfaces: (Detail 1). Toughseal can be used as a waterproof and chemically resistant wearing surface to plant rooms, bunded areas, pedestrian walkways etc. The second coat should be blinded with Aggregate Grade 2 if required at a rate of 1m2 /kg to provide slip retardant properties. Blinding should be carried out before the membrane begins to “skin over”.

Tile Bedding/Render Key: (Detail 2). Toughseal can be used to provide a water and water vapour barrier behind tiles, render or beneath thin levelling screeds. Reinforce the first coat of Toughseal, if required, with Toughseal Reinforcing Tape, prior to the application of the second coat. The second coat of the membrane should be blinded with Aggregate Grade 1 at a rate of 1m2 /kg to provide a key for the finishes. Blinding should be carried out before the membrane begins to “skin over”. For tiling onto timber/plasterboard substrates, refer to Tilesafe data.

Surface Applied Damp Proof Membrane: (Detail 3). Toughseal may be used as a surface applied damp proof membrane under raised access floors and/ or floor finishes at ground level. In this situation the material relies very heavily on a good bond with the substrate to resist water pressure so surface preparation should therefore be of a high standard

Detail 1 - Plant room detail,
horizontal wearing surface
Detail 1 - Plant room detail, horizontal wearing surface
Detail 2 -Tile Bedding/Render Key
Detail 2 -Tile Bedding/Render Key
Detail 3 - Ground Floor DPM
Detail 3 - Ground Floor DPM
Plinth detail
Plinth detail


Toughseal products can affect sensitive skins. Gloves or barrier cream should always be used by operatives and hands should be thoroughly washed at the end of each working period. Normal levels of air change are acceptable, however wear a suitable respirator if application is in an enclosed space. Do not allow the products to enter watercourses. Full health and safety instructions are contained on the product material safety data sheets, and these must be referred to before use. For details of Aggregates and Cleaning Solvent see separate material safety data sheets.

Raised access floor
Raised access floor



All RIW products can be obtained through Builders merchants or approved stockists. A list of approved stockists is available from RIW’s offices


Toughseal (two part)5 & 20 litre packs 
Aggregate (Grades 1 & 2)25kg bags
Cleaning Solvent5 litre containers
Toughseal Reinforcement Tape15m rolls


The shelf life of unopened containers stored in dry warm conditions is 12 months.


The RIW Technical Department is available to advise on individual projects and to prepare or assist in the preparation of specifications and drawings. A list of experienced applicators of RIW materials is available from RIW’s offices.


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