Sikalastic®-631
1-part low odour polyurethane liquid applied base coat for the SikaRoof® i-Cure system
Sikalastic®-631 is a 1-part, low odour, cold-applied, elastic, polyurethane base coat. It incorporates Sika's unique i-Cure technology and is part of the SikaRoof® i-Cure systems.
- The quick overcoating time provides early resistance to rain damage
- The low odour characteristics makes it suitable for odour sensitive projects
- A maintenance coat is easily applied when needed without the requirement to remove previous coats
- 1-Part ready to use
- Cold applied – requires no heat or flame
- High solid content
- Can be reinforced with Sika® Reemat Premium
- Resistant to many common environmental influences
- Easily detailed around complex geometries
- Applied by roller
Usage
The product can be used for the following roof waterproofing applications:- A base coat for SikaRoof®-15/-18/-22 i-Cure systems
- Flat and sloping fully exposed roof structures
- New construction and refurbishment projects
- Horizontal and vertical detailing around penetrations, drains, roof lights and complex geometries
- Failing roofs to extend the service life
- Sensitive areas requiring low odour
- Fibre cement
- Bitumen sheet membranes
- Bituminous coatings
- Bricks
- Concrete
- Ferrous metals
- Paints / Coatings
- Stone
- Ceramic tiles
- Wood
- The product is not suitable for permanent water immersion.
- The Product is not suitable for detailing works on single ply membranes.
- The Product may only be used for exterior applications.
Advantages
- The quick overcoating time provides early resistance to rain damage
- The low odour characteristics makes it suitable for odour sensitive projects
- A maintenance coat is easily applied when needed without the requirement to remove previous coats
- 1-Part ready to use
- Cold applied – requires no heat or flame
- High solid content
- Can be reinforced with Sika® Reemat Premium
- Resistant to many common environmental influences
- Easily detailed around complex geometries
- Applied by roller
Packaging
15 l metal containers
Colour
Oxide red (~RAL 3011)
Product Details
APPROVALS / STANDARDS
- Odournet – Report Number SIKA15A_roof_01_LW
- 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 (t1)(t4) as part of SikaRoof® i-Cure systems
- Reaction to fire according to EN 13501-1: Euroclass E as part of SikaRoof® i-Cure systems
Chemical Base
1-part, aromatic polyurethane
Shelf Life
12 months from date of production
Storage Conditions
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.
Density
~1.45 kg/l approx. (+23 °C)
Solid content by weight
~83.2 % (+23 °C / 50 % r.h.)
Solid content by volume
~78.0 % (+23 °C / 50 % r.h.)
System Structure
Refer to the System Data Sheets of SikaRoof® i-Cure systems
Tensile Strength
Unreinforced | Reinforced |
~5.6 N/mm2 | ~16.1 N/mm2 |
Service Temperature
-30 °C to +90 °C
Application
Ambient Air Temperature
+5 °C min. / +35 °C max.
Relative Air Humidity
20 % r.h. min. / 85 % r.h. max.
Substrate Temperature
+5 °C min. / +60 °C max.
Dew Point
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.
Substrate Moisture Content
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
Substrate Pre-Treatment
Refer to the System Data Sheets of SikaRoof® i-Cure systems
Pot Life
~30 minutes (+20 °C / 50 % r.h.)
- The product is formulated for fast curing.
- Material in opened containers must be applied immediately.
- Pot life will decrease at higher temperatures and increase at
lower temperatures.
Waiting Time / Overcoating
Ambient conditions | Minimum waiting time |
+5 °C / 50 % r.h. | ~14 hours |
+10 °C / 50 % r.h. | ~6–8 hours |
+20 °C / 50 % r.h. | ~3–4 hours |
+30 °C / 50 % r.h. | ~3 hours |
Note:After four 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.
Applied Product Ready for Use
Refer to System Data Sheets of SikaRoof® i-Cure systems
EQUIPMENT
Application equipment
- Fleece roller
- Squeegee
- Brush
SUBSTRATE PREPARATION
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 Sikalastic®-631 adhesion, carry out a small trial before full application together with adhesion tests as required.
Asbestos cement roof panels
- The roof panels must be in good structural condition, firmly bonded or mechanically fixed.
- Replace or fix any defective or loose panels.
- Thoroughly clean the surface in accordance with techniques that comply with local asbestos regulations and allow to dry if a wet technique is used.
- Remove dust by industrial vacuuming equipment.
- Any work involving asbestos must be in accordance with WorkSafe New Zealand's Approved Code Of Practice - Management and Removal of Asbestos
Bitumen sheet membranes
IMPORTANT
Always use a fully reinforced system over bitumen sheet membranes.
- Make sure the bituminous felt is firmly bonded or mechanically fixed to the substrate and does not contain any badly degraded areas.
- Remove completely or repair any degraded or missing sections.
- Volatile bitumen must be sealed with Sikalastic® Metal Primer before applying coating system.
- Remove loose granules/debris before continuing with installation process.
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.
- Bituminous, volatile mastic or old coal tar coatings must be sound, firmly bonded, rigid and with a tack free surface.
- Remove any loose layers.
- Thoroughly clean with soap and water and allow to dry.
- Apply Sikalastic® Metal Primer over the complete coating.
Brick and stone
- Brick, stone and mortar joints must be sound and preferably flush finished.
- Replace loose bricks, stone and mortar.
- Apply strips or sections of Sika® reinforcement over mortar joints.
- Thoroughly clean the surface by power washing and allow to dry.
Concrete
- 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.
- New concrete must be cured for at least 28 days and have a tensile strength > 1.5 N/mm2.
- 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.
- High spots can be removed by grinding.
- Weak cementitious substrates must be removed and surface defects such as blow holes and voids must be fully exposed.
- 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 Sikalastic®-631.
- Remove dust by industrial vacuuming equipment.
Ferrous metals
- Metals and existing coatings must be in a sound surface condition.
- Abrade surfaces to remove any rust and loose coatings.
- Bare metal must achieve a bright, rust-free finish.
- Prepare substrate mechanically using suitable abrading, grinding, rotating wire brush or other similar equipment.
- Apply Sikalastic® Metal Primer to optimise adhesion and protect metal from corrosion.
- 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.
- The existing paint / coating must be sound and firmly bonded to the substrate.
- Remove any oxidised or loose layers.
- Prepare substrate mechanically using suitable abrading, grinding, rotating wire brush or other similar equipment.
- Thoroughly clean the surface by power washing and allow to dry.
Unglazed ceramic tiles
- Make sure all tiles are securely fixed.
- Replace or fix any broken, loose or missing tiles.
- Thoroughly clean the surface by power washing and allow to dry.
Wood
- Wood and wood-based panel roof decks must be in good structural condition and firmly fixed.
- Replace or fix any defective or loose panels.
- 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.
- Remove any sharp protrusions from the surface.
- Prepare substrate mechanically using suitable wood abrading equipment.
- Remove dust by industrial vacuuming equipment.
- Apply Sika® Bonding Primer or Sika® Concrete Primer to entire timber surface, including upstands.
- Centre and apply Sikalastic®-100 SA Tape to timber panel joints.
MIXING
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.
- Sikalastic®-631 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.
APPLICATION
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.
- Pour the stirred/mixed primer onto the prepared substrate.
- Apply the product evenly over the surface with a brush or fleece roller.
- Back roll the surface in two directions at right angles with a fleece roller.
- The primer must be continuous, pore free and to the required surface finish.
Base coat
- Pour the stirred product onto the substrate. The consumption is specified in the System Data Sheets of SikaRoof® i-Cure systems.
- Apply the product evenly over the surface with a brush, fleece roller or a squeegee.
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.
- Lay Sika® Reemat Premium onto the wet base coat.
- Use a short pile roller to roll over the reinforcement and resin several times.
- The reinforcement fibres must be fully encapsulated within the resin.
- Protect product from heavy rain or rain showers until dry to prevent surface damage.
Top coat (Sikalastic®-641 TC)
- Pour the stirred product onto the substrate. The consumption is specified in the System Data Sheets of SikaRoof® i-Cure systems.
- Apply the product evenly over the surface with a brush, fleece roller or a squeegee.
- Back roll the surface in two directions at right angles with a fleece roller.
- Avoid going back to re-work areas that are partially dried as this may damage the surface finish.
- The coating must be continuous, pore free and to the required surface finish.
- Protect product from heavy rain or rain showers until dry to prevent surface damage
CLEANING OF TOOLS
Clean all tools and application equipment with Thinner C immediately after use. Hardened material can only be removed mechanically.