Sika® Decothane Ultra Base Coat

• Olfasense – Report Number SIKA23A_01
• CE Marking and Declaration of Performance to European Technical Assessment ETA-14/0177, based on ETAG 005 Part 1 and Part 6 — Liquid applied roof waterproofing kits. Part 1: General. Part 6: Specific stipulations for Kits based on Polyurethane
• Water Vapour Transmission Properties according to BS EN 1931:2000, Flexible Sheets for Waterproofing, Method B for Plastic or Rubber sheets
• External fire performance: Broof (t4)
• Reaction to fire according to EN 13501-1: Euroclass E

1-part, aromatic polyurethane

12 months from date of production

Product must be stored in original, unopened and undamaged packaging in dry conditions at temperatures between +0 °C and +25 °C. Always refer to packaging.

~1,45 kg/l approx. (+23 °C)

~83,2 % (+23 °C / 50 % r.h.)

~78,0 % (+23 °C / 50 % r.h.)

15 Year System

20 Year System

25 Year System

-30 °C to +90 °C

+5 °C min. / +35 °C max.

20 % r.h. min. / 85 % r.h. max.

Beware of condensation.
The substrate and uncured applied membrane must be at least +3 °C above dew point to reduce the risk of condensation or blooming on the
membrane finish.

+5 °C min. / +60 °C max.

The Product can be applied on substrates with a moisture content of ≤ 4 %.
The substrate must be visibly dry with no standing water.
The following test methods can be used to determine the substrate moisture content:
▪ Sika®-Tramex meter
▪ CM-measurement
▪ Oven-dry-method

Sika® Decothane Ultra Base Coat is designed for fast drying. High temperatures combined with high air humidity will increase the drying process. Thus, material in
opened containers should be applied immediately. In opened containers, the material will form a film within 30 minutes.

Note: After seven days, the surface must be cleaned and primed with Sika® Reactivation Primer before applying subsequent coats.

Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.

Application equipment

• Brush
• Roller

IMPORTANT
The supporting structure must be of sufficient structural strength to support the new and existing layers of the roof build-up. The complete roof system including existing layers must be designed and secured against wind uplift loadings.

General

• Tensile adhesion strength of the substrate must be a minimum of 1,5 N/mm2. If necessary, verify this by applying a test area first.
• Substrates must be free of standing water (no puddles) clean and free of all contaminants such as dirt, oil, grease, coatings, laitance, surface treatments and loose friable material.
• All dust, loose and friable material must be completely removed from all surfaces before application of the product and associated system products, preferably by industrial vacuuming equipment.
• To confirm adequate surface preparation and Sika® Decothane Ultra Base Coat adhesion, carry out a small trial before full application together with adhesion tests as required.

Asbestos cement roof panels

1. The roof panels must be in good structural condition, firmly bonded or mechanically fixed.
2. Replace or fix any defective or loose panels.
3. Thoroughly clean the surface in accordance with techniques that comply with local asbestos regulations and allow to dry if a wet technique is used.
4. Remove dust by industrial vacuuming equipment.

Bitumen sheet membranes*
IMPORTANT
Always use a fully reinforced system over bitumen sheet membranes.

1. Make sure the bituminous felt is firmly bonded or mechanically fixed to the substrate and does not contain any badly degraded areas.
2. Remove completely or repair any degraded or missing sections.
3. Treat surfaces as detailed below.

Surface treatment

• Mineral granules and talc finish: Remove loose granules and apply Sika® Decothane Ultra Base Coat
• Sikalastic® Metal Primer should be applied to fresh or volatile bitumen to prevent staining and bleed through.
• Polyethylene foil finish: Warm foil finish by lightly gas torching.
• Texflamina finish: Must be new.

Bituminous coatings*
IMPORTANT
Always use a fully reinforced system over bituminous coatings.
IMPORTANT
Old existing coatings which are not fully bonded to substrate must be removed.

1. Bituminous, volatile mastic or old coal tar coatings must be sound, firmly bonded, rigid and with a tack free surface.
2. Remove any loose layers.
3. Thoroughly clean with soap and water and allow to dry. 
4. Apply Sikalastic® Metal Primer or similar (e.g. Sikalastic U-Primer) over the complete coating.

Brick and stone

1. Brick, stone and mortar joints must be sound and preferably flush finished.
2. Replace loose bricks, stone and mortar.
3. Apply strips or sections of Sika® reinforcement over mortar joints.
4. Thoroughly clean the surface by power washing and allow to dry.

Concrete

1. Substrate must be sound with a minimum tensile adhesion strength of 1,5 N/mm2, clean, dry and free of all contaminants such as dirt, oil, grease, coatings, laitance, surface treatments and loose friable material.
2. New concrete must be cured for at least 28 days and have a tensile strength > 1,5 N/mm2.
3. Substrates must be prepared mechanically using suitable substrate preparation equipment to remove cement laitance and achieve an open textured gripping surface profile suitable for the product thickness.
4. High spots can be removed by grinding.
5. Weak cementitious substrates must be removed and surface defects such as blow holes and voids must be fully exposed.
6. Repairs to the substrate, filling of joints, blowholes/voids and surface levelling must be carried out using appropriate products from the Sikafloor ®, Sikadur® and Sikagard® range of materials. Products must be cured before applying Sika® Decothane Ultra Base Coat.
7. Remove dust by industrial vacuuming equipment.

Ferrous metals

1. Metals and existing coatings must be in a sound surface condition.
2. Abrade surfaces to remove any rust and loose coatings.
3. Bare metal must achieve a bright rust-free finish.
4. Prepare substrate mechanically using suitable abrading, grinding, rotating wire brush or other similar equipment.
5. Apply Sikalastic® Metal Primer to optimise adhesion and protect metal from corrosion.
6. Apply strips or sections of Sika® reinforcement over joints and fixings.

Paints / Coatings
IMPORTANT
Old existing coatings which are not fully bonded to substrate must be removed.

1. The existing paint / coating must be sound and firmly bonded to the substrate.
2. Remove any oxidised or loose layers.
3. Prepare substrate mechanically using suitable abrading, grinding, rotating wire brush or other similar equipment.
4. Thoroughly clean the surface by power washing and allow to dry.

Wood

1. Wood and wood-based panel roof decks must be in good structural condition, firmly bonded or mechanically fixed.
2. Replace or fix any defective or loose panels.
3. Make sure that any nail or screw heads that are protruding above the surface of the top of the deck are hammered or screwed below the surface.
4. Remove any sharp protrusions from the surface.
5. Prepare substrate mechanically using suitable wood abrading equipment.
6. Remove dust by industrial vacuuming equipment

* Over new (fresh) bituminous membranes or substrates, bleed through of volatiles can lead to staining or discolouration and reduced long-term aesthetics of the coating. The use of Sikalastic Metal Primer as a barrier will prevent this and lead to best long-term aesthetic performance.

IMPORTANT
Do not dilute with solvent or water.
Note: Mixing is not required, however if the product has separated, stir gently by manual or mechanical equipment thoroughly to achieve a uniform colour.

• Sika® Decothane Ultra Base Coat is supplied ready for use.
• Before application, mix for at least 1 minute or until the liquid and all the coloured pigment has achieved a uniform colour.

Strictly follow installation procedures as defined in Method Statements, application manuals and working instructions which must always be adjusted to the actual site conditions.

Note: Protect areas adjacent to the application from splashes with tape or plastic wrapping.

Note: Confirm waiting / overcoating times of any previous coats, is achieved before applying subsequent coats. (Refer to waiting / overcoating time in Application Information)

Note: Confirm product application conditions: substrate moisture content, substrate, air and product temperatures, relative humidity and dew point (Refer to Application information).

Note: Always begin application with detailing (i.e. corners, upstands, joints etc) before installation of the main horizontal surfaces.

Reinforced coating system Primer (If required)

IMPORTANT
Make sure the primer on the substrate is continuous and pore free.

Note: Refer to individual primer Product Data Sheet.

1. Apply the mixed primer onto the prepared substrate.
2. Apply the product evenly over the surface with a brush or roller.
3. Back roll the surface in two directions at right angles with a roller.
4. The primer must be continuous, pore free and to the required surface finish. 

Base coat

1. Apply the Product onto the substrate. The consumption is specified in the System Data Sheets of the require primer.
2. Apply the Product evenly over the surface with a brush or roller.

Reinforcement
IMPORTANT
Make sure reinforcement overlaps are greater than 50 mm.

Note: It is recommended to work 1,0 m at a time lengthways applying the 1st coat and embedding the reinforcement.

1. Lay the appropriate Sika® Reinforcement onto the wet base coat.
2. Use a short pile roller to roll over the reinforcement and coating several times.
3. The reinforcement fibres must be fully encapsulated within the coating.
4. Protect Product from heavy rain or rain showers until dry to prevent surface damage.

Top coat (Decothane Ultra)

1. Apply the Product onto the substrate. The consumption is specified in the Product Data Sheet for Decothane Ultra.
2. Apply the Product evenly over the surface with a brush or roller.
3. Back roll the surface in two directions at right angles with a roller.
4. Avoid going back to re-work areas that are partially dried as this may damage the surface finish.
5. The coating must be continuous, pore free and to the required surface finish. 
6. Protect Product from heavy rain or rain showers until dry to prevent surface damage

Clean all tools and application equipment with Thinner C immediately after use. Hardened material can only be removed mechanically.