Sikafloor®-81 EpoCem® New HC
3-part cement and epoxy combination mortar for selfsmoothing floor screeds of 1.5 to 3 mm
Sikafloor®-81 EpoCem® New HC is a three part, epoxy modified cementitious, fine textured mortar for self smoothing floor screeds in thin layers of 1.5 to 3 mm.
- Can be overcoated with epoxy resin compounds after 24 hours (20 °C, 75 % r.h.)
- Prevents osmotic blistering of resin based coatings over damp substrates
- Economical and fast, easy application
- Good levelling properties
- Impervious to liquids but permeable to water vapour
- Frost and de-icing salt resistant
- Thermal expansion properties similar to concrete
- Excellent bond to green or hardened concrete whether damp or dry
- Excellent early and final mechanical strengths
- Excellent resistance to water and oils
- Ideal preparation for smooth surface finishes
- For internal use
- Contains no solvents
- Will not corrode reinforcement
Usage
As a Temporary Moisture Barrier (TMB) (min. 2 mm thick) allowing the application of Epoxy, Polyurethane and PMMA* resin floors requiring dry substrates, over high moisture content substrates, even green concrete, for a lasting solution. As a self-smoothing screed for:- Levelling or patching horizontal concrete surfaces, in new work or repairs, in aggressive chemical environments
- Floor topping on non-ventilated damp substrates without particular aesthetic requirements
- Levelling layer under Epoxy, Polyurethane and PMMA* floor coatings / screeds, tiles, sheet floors, carpets or wooden floors
- Repair and maintenance of monolithic and vacuum concrete floors
- Under Epoxy, Polyurethane and PMMA floor coatings / screeds
Advantages
- Can be overcoated with epoxy resin compounds after 24 hours (20 °C, 75 % r.h.)
- Prevents osmotic blistering of resin based coatings over damp substrates
- Economical and fast, easy application
- Good levelling properties
- Impervious to liquids but permeable to water vapour
- Frost and de-icing salt resistant
- Thermal expansion properties similar to concrete
- Excellent bond to green or hardened concrete whether damp or dry
- Excellent early and final mechanical strengths
- Excellent resistance to water and oils
- Ideal preparation for smooth surface finishes
- For internal use
- Contains no solvents
- Will not corrode reinforcement
Packaging
Pre-batched 23 kg units.
| Part A | 1.14 kg plastic container |
| Part B | 2.86 kg plastic container |
| Part C | 19.00 kg bag |
Colour
| Part A - resin | White liquid |
| Part B - hardener | Turbid yellowish liquid |
| Part C - filler | Natural grey aggregate powder |
| Colour | Light grey |
| Finish colour | Matt grey |
Product Details
Composition
Epoxy modified cementitious mortar.
Shelf Life
| Part A, Part B | 12 months |
| Part C | 9 months |
Storage Conditions
The product must be stored in original, unopened and undamaged sealed packaging, in dry conditions at temperatures between +18 °C and +30 °C.
Part A, part B : Protect from frost and direct sunlight
Part C : Protect from humidity and direct sunlight
Density
| Part A | ~1.09 kg/l |
| Part B | ~1.03 kg/l |
| Part C | ~1.72 kg/l |
| Mixed A+B+C | ~2.10 kg/l |
Compressive Strength
| 1 day | ~15 N/mm² |
| 7 days | ~38 N/mm² |
| 28 days | ~44 N/mm² |
Tensile Strength in Flexure
| 28 days | ~10 N/mm² |
Chemical Resistance
The Sikafloor® EpoCem® product range has improved chemical resistance over plain concrete in aggressive environments, but is not designed as a chemical protection. For specific chemical resistance, always overcoat with a suitable product from the Sikafloor® and Sikagard® range. For occasional exposure or spillages, consult technical department.
Application
Mixing Ratio
Part A : part B : part C - packing size : 1.14 : 2.86 : 19 kg
Flooring Screed:
At temperatures between +12 °C to +25 °C:
1 : 2.5 : 17 (by weight)
Parts (A+B) : C = 4 kg : 19 kg
At temperatures between +8 °C to +12 °C and +25 °C to +30 °C:
The amount of Part C can be reduced to 18 kg in order to improve workability.
Please note:
Never reduce Part C by more than this amount.
1 : 2.5 : 15.8 (by weight)
Parts (A+B) : C = 4 kg : 18 kg
Extended mortar mix. Repair mortar:
To repair surface irregularities and holes 3 to 5 cm in diameter and deeper than 3 mm and up to 9 mm the standard Sikafloor®-81 EpoCem® New HC mix can be extended with dry quartz sand.
For each 23 kg unit of Sikafloor®-81 EpoCem® New HC prepared as indicated below, add:
- Sikadur®-509 (quartz sand 0.7–1.2 mm) 5–10 kg and
- Sikadur®-510 (quartz sand 2.0–3.0 mm) 5–10 kg
Final mix will be : 33–43 kg
For this application, to achieve a good bond of the mortar to the substrate,
SikaTop®-Armatec®-110 EpoCem® must be used as bonding bridge. Apply the mortar wet on wet to the primer.
Ambient Air Temperature
+8 °C min. / +30 °C max.
Layer Thickness
1.5 mm min. / 3.0 mm max.
If Sikafloor®-81 EpoCem® New HC is used as a Temporary Moisture Barrier (TMB), a minimum of 2 mm must be applied.
Relative Air Humidity
20 % min. / 80 % max.
Substrate Temperature
+8 °C min. / +30 °C max.
Substrate Moisture Content
Can be applied on green or damp concrete, without any standing water.
Although the product can be applied onto green concrete surfaces (> 24 hours), it is advised to allow at least 3 days for early shrinkage of concrete to occur in order to prevent concrete shrinkage cracks from appearing on the screed surface.
Pot Life
| Temperature / R.H. 75 % | Time |
| +10 °C | ~40 min |
| +20 °C | ~20 min |
| +30 °C | ~15 min |
23 kg units
Curing Time
Once Sikafloor®-81 EpoCem® New HC is tack free it is possible to apply vapour permeable seal coats.
For the application of vapour tight coatings on Sikafloor®-81 EpoCem® New HC, allow the surface moisture to fall below 4 %, not earlier than:
| Substrate Temperature | Waiting Time |
| +10 °C | ~2 days |
| +20 °C | ~1 day |
| +30 °C | ~1 day |
Consumption
| Primer | SikaRepair® EpoCem Modul HC or Sikafloor-80 EpoCem® Primer (~0.3 kg/m²) |
| Self smoothing screed: | Sikafloor®-81 EpoCem® New HC ~2.25 kg/m²/mm |
These figures are theoretical and do not allow for any additional material due to surface porosity, surface profile, variations in level or wastage, etc.
MIXING
Prior to mixing, shake part A (white liquid) briefly until homogenous, then pour into container of part B and shake vigorously again for at least 30 seconds. When dosing out of drums, stir and homogenise first.
Pour the mixed binder mixture (A+B) into a suitable mixing container (capacity of about 30 litres) and gradually add part C to the mixer while stirring with a power mixer. Mix thoroughly for 3 minutes until a uniform mix has been achieved with no lumps.
Mix only full units of A+B+C components. Do not mix smaller amounts. Do not add water.
When dosing with additional aggregates, add them after adding part C to the mix. Mix thoroughly for 3 minutes until a uniform mix has been achieved.
Mixing Tools
Mix using a slow speed electric mixer (300–400 rpm) with helical paddle or other suitable equipment.
For mixing 2–3 bags at once, single or counter rotating double mortar (basket type) and forced action (pan type) mixers are also recommended. Free fall mixers must not be used.
APPLICATION
Place mixed Sikafloor®-81 EpoCem® New HC onto the primed substrate and spread evenly to the required thickness uniformly with a rubber or metal trowel or spatula and immediately roll with a spike roller to remove entrapped air and obtain an even thickness layer. Workability can be adjusted by varying slightly the amount of part C. Do not use additional water, which would disturb the surface finish and cause discolouration. A seamless finish can be achieved if a ‘wet’ edge is maintained during application.
CLEANING OF TOOLS
Clean all tools and application equipment with water immediately after use. Hardened / cured material can only be removed mechanically.
CLEANING
Due to the texture of its surface, Sikafloor®-81 EpoCem® New HC is not suitable to be used as wearing layer where easy staining can occur. A seal coat of the Sikafloor® range with suitable cleaning capabilities is advisable.
Remove dirt using a brush and/or vacuum. Do not use wet cleaning methods until the product is fully cured.
Do not use abrasive methods or cleaners.