Product Data Sheet Show all documents
Sika® Ucrete® UL

Sika® Ucrete® UL

(former Ucrete® UL)

Heavy-duty, cementitious, underlayment screed for Sika® Ucrete® flooring systems

Sika® Ucrete® UL is a one-part, fast-curing, shrinkage compensated underlayment screed for use beneath Sika® Ucrete® flooring systems. It is a ready-to-use material that contains special hydraulic binders, well-graded sands and specifically selected polymers. Depending on the mixing water addition, the consistency of the mortar can be adjusted to provide a thixotropic material for application to falls or a fluid material for levelling or pumping.

  • Fast curing and fast strength-development at low temperature allows for early preparation and application of Sika® Ucrete® flooring after 16 hours at +10 °C
  • Very good resistance to thermal shock when used as part of a Sika® Ucrete® flooring system
  • Very good workability and finishing in all consistencies
  • Easy to apply and lay as a monolithic flat floor finish or on a slope
  • Low shrinkage, reducing stress on the substrate and reducing the risk of cracking
  • Pre-batched, one-part mortar that only needs the addition of water
  • Suitable for internal or external application, on all horizontal surfaces, in dry and wet environments
  • Layer thickness of 10–100 mm
Product Data Sheet Show all documents

Usage

Sika® Ucrete® UL is used as an underlayment screed for Sika® Ucrete® flooring systems. Please note:
  • The Product may only be used by experienced professionals.
 

Advantages

  • Fast curing and fast strength-development at low temperature allows for early preparation and application of Sika® Ucrete® flooring after 16 hours at +10 °C
  • Very good resistance to thermal shock when used as part of a Sika® Ucrete® flooring system
  • Very good workability and finishing in all consistencies
  • Easy to apply and lay as a monolithic flat floor finish or on a slope
  • Low shrinkage, reducing stress on the substrate and reducing the risk of cracking
  • Pre-batched, one-part mortar that only needs the addition of water
  • Suitable for internal or external application, on all horizontal surfaces, in dry and wet environments
  • Layer thickness of 10–100 mm

Packaging

20 kg

Refer to the current price list for available packaging variations.

Colour

Grey

Product Details

Product Information

Chemical Base

Special cements

Shelf Life

9 months from date of production

Storage Conditions

The Product must be stored in original, unopened and undamaged packaging in dry conditions at temperatures between +5 °C and +35 °C. Always refer to the packaging.

Refer to the current Safety Data Sheet for information on safe handling and storage.

Maximum Grain Size

Maximum diameter: 2 mm

 
Technical Information

Compressive Strength

Conditioned 24 h at +5 °C

≥ 45 N/mm2

Conditioned 24 h at +23 °C

≥ 50 N/mm2

Conditioned 72 h at +5 °C

≥ 55 N/mm2

Conditioned 72 h at +23 °C

≥ 60 N/mm2

Conditioned 28 d at +23 °C

≥ 70 N/mm2

Conditioned 28 d at +23 °C

≥ 80 N/mm2

Flexural Strength

Conditioned 24 h at +23 °C

≥ 7.0 N/mm2

Conditioned 72 h at +23 °C

≥ 7.5 N/mm2

Conditioned 7 d at +23 °C

≥ 9.0 N/mm2

Conditioned 28 d at +23 °C

≥ 10.0 N/mm2

Tensile adhesion strength

≥ 3.0 N/mm2

(EN 1542)

Reaction to Fire

Class A1fl

(EN 13501-1)

Capillary Absorption

≤ 0.5 kg/m²/h½

(EN 13057)

Application

Application Information

Fresh mortar density

2.2 kg/L

(EN 1015-6)

Layer Thickness

Maximum

100 mm

Minimum

10 mm

Product Temperature

Maximum

+30 °C

Minimum

+5 °C

Ambient Air Temperature

Maximum

+30 °C

Minimum

+5 °C

Mixing Ratio

Bonding slurry

2.6–2.9 L

Pourable consistency

2.5–2.9 L

Thixotropic consistency

1.9–2.1 L

Substrate Temperature

Maximum

+30 °C

Minimum

+5 °C

Waiting Time / Overcoating

Temperature

Waiting time

+10 °C

16 hours

Note: Times are approximate and will be affected by changing ambient and substrate conditions.
Consumption

Consumption

2.2 kg/m2 per mm of thickness.

Approximately 2000 kg per 1 m3 of fresh mortar.

Note: Consumption data is theoretical and does not allow for any additional material due to surface porosity, surface profile, variations in level, wastage or any other variations. Apply the Product to a test area to calculate the exact consumption for the specific substrate conditions and proposed application equipment.

Yield

10.5 L

Note: Consumption data is theoretical and does not allow for any additional material due to surface porosity, surface profile, variations in level, wastage or any other variations. Apply the Product to a test area to calculate the exact consumption for the specific substrate conditions and proposed application equipment.
Application steps

SUBSTRATE PREPARATION

IMPORTANT

Surface defects due to voids in the substrate

Voids and blow holes in the substrate will weaken the surface and damage the covering Product if not repaired during the preparation process.

  1. Fully expose blow holes and voids during surface preparation to identify the required repairs.

TREATMENT OF JOINTS AND CRACKS

Construction joints and existing static surface cracks in substrate require pre-treating before full layer application. Use Sikadur® or Sikafloor® resins.

  1. Remove weak cementitious substrates.
  2. IMPORTANT The final texture of the substrate must be open-textured and gripping. Prepare cementitious substrates mechanically using abrasive blast cleaning, planing or scarifying equipment to remove cement laitance.
  3. Before applying the Product, remove all dust, loose and friable material from the application surface with an industrial vacuuming equipment.
  4. Bring edge and movement joints through the floor surface. Note Protect the joints so the Product cannot flow into them.
  5. To prevent the Product from bonding, install isolating strips to vertical perimeter surfaces such as pipes, ducts, conduits, walls, columns.
  6. Prewet the prepared cementitious substrate for at least 2 hours before application. Note Before starting the bonding slurry application, the surface must be mat-damp, but without standing water.

For additional information on products for leveling and repairing defects, contact Sika® Technical Services.

MIXING

SMALL TO MEDIUM VOLUMES

  1. Pour the minimum recommended clean water quantity into a suitable mixing container.
  2. While stirring slowly with electric paddle mixer, add the powder to the water and mix thoroughly for at least for 3 minutes.
  3. Additional water can be added up to the maximum specified amount to adjust the consistency to achieve a smooth consistent mix.
  4. Check the consistency after every mix.

LARGE VOLUMES

  1. Pour the minimum recommended clean water quantity into the forced action mixer or rotating pan or continuous mortar mixer and integral delivery pump.
  2. Add the powder to the water and mix thoroughly for at least for 3 minutes to achieve a smooth consistent mix.
  3. Check the consistency and record results in a jobsite quality control plan.
  4. Compare mixing consistency with drill and mixing paddle technique.

APPLICATION

BONDING SLURRY FOR PRIMING

  1. Apply the Product to the prepared substrate and work in thoroughly using a hard bristle broom. Ensure the entire surface is fully covered.
  2. Do not allow the bonding slurry to dry. Apply the subsequent thixotropic or levelling layer wet-on-wet.

THIXOTROPIC FOR APPLICATION TO FALLS

  1. Apply the Product to the bonding slurry and spread to the required thickness with a trowel.
  2. Compact the mortar using a vibrating tamper or trowel.
  3. Go over the surface with a levelling board and rub down with a wooden board.
  4. Smooth surface with a finishing trowel if necessary. 

FLUID FOR LEVELLING OR PUMPING

  1. Pour or pump the Product onto the wet bonding slurry.
  2. Spread the material to the desired thickness.
  3. Smooth surface with a finishing trowel if necessary. 

CURING TREATMENT

Freshly applied Sika® Ucrete® UL must be protected for approximately 6 hours against rapid drying in hot weather, strong wind or if used outdoors.

Surface preparation and application of the following Sika® Ucrete® layers is possible after 16 hours at +10 °C, in most cases.

CLEANING OF TOOLS

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

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