Sikafloor®-21 PurCem® LP

• Conforms to the requirements of EN 13813: 2002 as CT - C50 - F10 - AR0.5.
• Certified as suitable for use in food and beverage facilities that operate in accordance with a HACCP based food safety programme, dated 23 October 2023.
• Thermal Compatibility between Concrete and An Epoxy-Resin Overlay in accordance with ASTM C884 / C884M-16, Report No. MIS 017/21/R 0129(A), April 2021.
• Absorption of Chemical-Resistant Mortars, Grouts and Monolithic Surfacings in accordance with ASTM C413-18, March 2021.
• Wear Resistance - BCA in accordance with BS EN 13892-4:2002, March 2021.
• All other values indicated are internal test results.

Part A : Water borne polyol
Part B : Isocyanate
Part C : Aggregates, cement and active fillers

If stored properly in original, unopened and undamaged sealed packaging, in dry conditions at temperatures between +18 °C and +30 °C.

(1.5 N/mm² is the minimum pull off strength of the recommended concrete substrate)

Resistant to many chemicals. Please ask for a detailed chemical resistance chart.

The product is not designed to withstand thermal shock. Hot steam cleaning is not recommended. Use Sikafloor®-20 PurCem® LP 9 mm.
Sikafloor®-21 PurCem® LP can be subject to thermal shock < 70 °C at 6 mm.

Part A : B : C = 1 : 1 : 4.67 (packaging size = 3 : 3 : 14) by weight

3 mm min. / 6 mm max

+10 °C min. / +30 °C max.

+10 °C min. / +35 °C max.

85 % max.

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

+10 °C min. / +30 °C max.

The substrate can be dry or damp (saturated surface dry or SSD) with higher moisture content (No ponding water). Check rising moisture.

The substrate needs to be visibly dry and have adequate pull-off strength min. 1.5 N/mm².

Notes: Times are approximate and will be affected be changing ambient and substrate conditions, particularly temperature and relative humidity.
If used other primers than Scratch Coat refer the Technical Data Sheet of the respective product. Make sure that the primer and the scratch coat layer is fully cured before application of Sikafloor® PurCem® previous layer.

This figure is theoretical and does not allow for any additional material due to surface porosity, surface profile, variations in level or wastage etc.

MIXING EQUIPMENT

• Electric single paddle mixer (300 to 400 rpm)

• Electric double paddle mixer (>700 W, 300 to 400 rpm)

APPLICATION EQUIPMENT

• Flat, round edge steel trowel

• Spiked roller

• Trowels, including serrated

• Pin leveller (optional)

TREATMENT OF JOINTS AND CRACKS

IMPORTANT

Incorrect treatment of cracks

• The incorrect assessment and treatment of cracks may lead to a reduced service life and reflective cracking.
• Construction joints and existing static surface cracks in substrate require pre-treating before full layer application. Use Sikadur® or Sikafloor® resins.

The System can be applied on green or damp concrete with no standing water. Allow for at least 3 days for early concrete shrinkage to occur to prevent shrinkage cracks from appearing on the wearing surface.

Cementitious substrates (concrete / screed) must be structurally sound and of sufficient compressive strength (minimum 25 N/mm²) with a minimum tensile strength of 1.5 N/mm².

Substrates must be clean, dry and free of all contaminants such as dirt, oil, grease, coatings, laitance, surface treatments and loose friable material.

Substrate priming is normally not required under typical circumstances. However due to variations in concrete quality, surface conditions, surface preparation and ambient conditions, reference test areas are recommended to determine whether priming is required to prevent the possibility of blisters, de-bonding pinholes and other aesthetic variations.

Sikafloor® PurCem® can be applied onto recent concrete over 7 to 10 days old or onto old damp concrete (SSD) without having to prime first, as long as the substrate fulfils the above requirements.

• Concrete substrates must be prepared mechanically using abrasive blast cleaning or scarifying equipment to remove cement laitance and achieve an open textured surface to achieve CSP 3-6 according to the International Concrete Repair Institute.
• Weak concrete must be removed and surface defects such as blow holes and voids must be fully exposed.
• Repairs to the substrate, filling of blowholes/voids and surface levelling must be carried out using appropriate products from the Sikafloor®, SikaDur® and Sikagard® range of materials.
• High spots can be removed by grinding.
• All dust, loose and friable material must be completely removed from all surfaces before application of the product, preferably by brush and/or vacuum.
• To prevent curling of the applied product during curing, place retaining grooves in the substrate along all exposed edges (perimeter, joints, working day joints, connections, plinths, columns, covings and drains / gullies). Width and depth of grooves must be twice the thickness of the floor finish.
• Edge terminations. All free edges and working day joints of Sikafloor®-21 / -20 PurCem® LP, whether at the perimeter, along gutters or at drains require extra anchorage to distribute mechanical and thermal stresses. This is best achieved by forming or cutting grooves in the concrete. Grooves must have a depth and width of twice the thickness of the Sikafloor®-PurCem®. Refer to the edge details provided in the Method Statement. If necessary, protect all free edges with mechanically attached metal strips. Never featheredge, always turn into an anchor groove.
• Expansion joints must be provided in the substrates at the intersection of dissimilar materials. Isolate areas subject to thermal stresses, vibration movements or around load-bearing columns and at vessels sealing rings.

IMPORTANT

Mix full units only

3 PART MIXING PROCEDURE

1. Material and ambient temperature will affect the mixing process. If necessary, condition the materials for best use to +18 °C to +27 °C.
2. Mix Part A (resin) until the coloured pigment is dispersed and a uniform colour is achieved.
3. Premix Part B (hardener) separately then add Part B (hardener) to Part A.
4. Mix Part A + B continuously for 30 seconds until a uniformly coloured mix is achieved.
5. After mixing for 30 seconds, gradually add Part C over a period of 15 seconds while you continue mixing.
6. After combining all parts, mix for an additional 90 seconds, until a uniform mix is achieved. Note: At ambient temperatures less than +15 °C mix between 30 seconds and 1 minute longer. Use a low speed electric stirrer (300 - 400 rpm) for mixing parts A+B+C.
7. To ensure thorough mixing, pour materials into another container and mix again to achieve a smooth and uniform mix.
8. During the final mixing stage, scrape down the sides and bottom of the mixing container with a flat or straight edge trowel at least once to ensure complete mixing.

When adding aggregate to prepare a patching / levelling mortar, gradually add the 6 kg of 2 - 3 mm dry quartz sand immediately after mixing the full set. For preparation of the mortar mix use a pan type revolving mixer.

IMPORTANT

Prior to application

Confirm substrate moisture content, r.h. and dew point meet the requirement.

Protecting the material after application

After application, protect the System from damp, condensation and direct water contact for at least 24 hours.

Protect from overhead leaks and condensation

Protect the Product during application from pipe condensation or any overhead leaks.

Ventilation in confined spaces

Always ensure good ventilation when applying the Product in a confined space.

Application on polymer modified cement mortars

Do not apply the product on polymer modified cement mortars if the mortar expands when sealed with an impervious resin.

Waiting time for foodstuff

Allow a minimum of 48 hours after application before placing foodstuff in the same area.

SCRATCH COAT

1. Pour the mixed Product onto the prepared substrate.
2. Scrape the Product into the prepared surface with a steel trowel to the required thickness so that the surface texture is filled.

WEARING LAYER

1. Pour the mixed Product onto the substrate. Note: The consumption is specified in Application Information.
2. Apply the Product evenly over the surface with a pin leveller or a trowel. Straight edge trowel can also be used to smooth out the marks of the tooth trowel or instead of it. Take care to spread newly placed materials across the transition of previously applied mixes before the surface begins to set.
3. Back roll the surface in two directions at right angles with a spike roller (less than two minutes after placing). Note: Maintain a "wet edge" during application to achieve a seamless finish. Roller spikes must be at least three times longer than the product thickness applied.
4. Ensure overlap between mixed material is below 10 minutes at +30 °C. Please conduct field test to ensure the overlap time.

Allow a minimum 18 hours cure period at +30 °C before light traffic.

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

To maintain the appearance of the floor after application, Sikafloor®-21 PurCem® LP must have all spillages removed immediately and must be regularly cleaned using rotary brushes, mechanical scrubbers, scrubber dryers, high pressure washers, wash and vacuum techniques, etc., using suitable detergents and waxes.