M1 emission classification for building material
LEED

A self-levelling, normal drying cement based pumpable screed.

Special features

  • pumpable
  • fibre-reinforced
  • low alkali

Materials

Product Information
Application

Kiilto Express K is a self-levelling, normal drying, fibre-reinforced cement based pumpable screed. Also suitable for manual application.

Suitable for new build and renovation in homes, offices and public premises. Not suitable for industrial applications. Used for levellings as well as for construction of slopes in interior areas. Suitable substrates include concrete, lightweight concrete and ceramics/natural stone.

Kiilto Express K is used for bonded and unbonded (floating) constructions. Also compatible with both electric and water underfloor heating.

Needs to be finished with a surface material, for example, with a wall-to-wall carpet, floating parquet or ceramic tile.

A low alkali screed layer protects the adhesive and vinyl coating from the damages caused by alkali moisture in the concrete. Tests have shown that a 5 mm screed layer provides a protective effect.

Technical Information
Application temperature

+10–25 °C (mixed mass)

Bond strength

> 1,5 MPa

Classifications and certificates

CT-C20-F5 (EN 13813), M1

Coatable

1 day / 1 mm (max. 30 mm) (+23°C, 50 % RH)
2-3 days/1 mm (> 30 mm) (+23°C, 50 % RH)
Unfavourable drying conditions will retard drying.

For installation of flooring, follow national standards and the flooring manufacturer's instructions.

Compression strength

C20 (> 20 MPa), EN 13813

Coverage

approx. 1.7 kg powder/m²/mm

Durability

RWFC 350
(EN 13813)

Fire class

A1

Flexural strength

F5 (F > 5 MPa), EN 13813

Layer thickness

3–40 mm*

min. 20 mm screed on top of the underfloor heating pipes / cables

* With thin layers take into account product's spreading properties.

Mixing ratio

3.4 - 4.0 litres / 20 kg powder (water amount 17–20 %)

Shrinkage

< 0.03 %

Storage

In an unopened package 6 months in dry conditions

Substrate humidity

Concrete < 90 % RH

Type/binder

Resin-cement-quartzsandbased powder

Walkable

1–3 h

Working conditions

Substrate and room temperature +10-25 °C

Working time

Mixed mass must be use within 15 minutes after mixing.

pH

< 11

Instructions and Safety
Instructions for use

A bonded floor construction:
Ensure that the substrate is suitable for the product, e.g. sufficiently strong concrete. The substrate must be clean, dry, even, free form cracks, uncoated, free from grease and oil and any other substances that might impair adhesion and the final result. Remove cement laitance and smooth out irregularities. Smooth and dense surfaces must be sanded mechanically or ground to ensure proper adhesion, if necessary. The documented bond strength of the substrate must be 1.0 MPa at the minimum.

Required layer thicknesses:
Concrete: 3-40 mm
Lightweight concrete: 6-20 mm
Ceramics/natural stone: 3-40 mm

Movement joints in the substrate:
If movement joints are required, make them into the screed layer, down to the substrate. They are placed at the same position with the movement joints in the substrate. Joint width must be 10-15 mm. There may also be alternative solutions.

A floating floor construction:
The total layer thickness must always be 30 mm at the minimum and a steel mesh (Ø3 mm 50x100 mm) or a fibreglass mesh must always be used with the screed. The reinforcement mesh is installed with min. 50 mm overlaps. The screed is separated from the substrate with e.g. a filter cloth. Larger surfaces must be divided in smaller, separated sections.

The surface under a floating surface material must be sufficiently smooth. The surface is sanded or smoothed, if necessary. For floating constructions, the surface materials must be installed as soon as possible. If the floor is left uncovered for a longer period, the levelled floor must be primed with Kiilto Primer 001 diluted with water (1 part primer : 3 parts water) on the next day after levelling to prevent the floor from cracks and edge rise.

Preparation:
Correct temperature is vital for a successful result. The substrate temperature must be min. +10 °C. The temperature must be monitored and ensured well before priming. A higher temperature is beneficial for the quality and drying time. Maximum temperature +25 °C.

Priming:
Always prime the substrate with Kiilto Primer 001 according to the instructions given in the technical data sheet. Apply primer 1-48 h prior to levelling, and always let dry before applying the screed. However, do not let the primer dry for more than 3 days, since the construction dust and other impurities may adhere to the primer coat and impair the adhesion of the screed. Note, if the primer is applied on larger areas with a so called primer pump, the primer must always be rubbed onto the substrate with a brush.
In case of non-absorbent substrates, please contact Kiilto contact person (pumpable screeds).

Mixing:
Make sure that the screed is homogenous and consistent, fluid and free from lumps. When making slopes, reduce the amount of water to ensure right consistency. Water temperature: +5...+20°C.

Application:
Kiilto Express K is pumped straight from the pumping truck on the substrate in stripes. Apply a new stripe on a previous one as soon as possible, so that they blend in and form an even and smooth layer. Make sure that the width of the stripes do not exceed 10 meters. Larger areas must be divided into smaller sections.
Check carefully that the drains and other penetrations are sealed properly before applying the screed to avoid clogging up the discharge pipes and having screed spilled on surrounding surfaces.

Work the screed with a notched trowel or similar tool to ensure as smooth a surface as possible. If applying several screed layers, apply primer between each layer. Let the first screed layer dry for at least 24 hours prior to priming. Check and make sure that the surface is so dry that the substrate absorbs the primer.

Mixing ratio when priming a new screed layer:
Mix Kiilto Primer 001 in 3-10 parts of water depending on the drying conditions and the subtrate's absorbency. Apply primer twice, if using over 7 parts of water.

Semi-hardened screed is easy to mold or cut. If planning to make levellings, do not wait too long.

Drying:
The drying time of the screed depends on the substrate 's humidity, layer thickness, temperature of the structure and air and relative air humidity of the area. Effective ventilation accelerates drying.

Kiilto Express K is a normal drying screed and the reference value for drying is 1 d/mm at 20 °C, RH 50% with good ventilation. Screed layers over 30 mm thick, one-sided drying, low temperature and / or high humidity will retard drying.

Kiilto Express K can be applied on concrete with RH 90%.
Note: The screed cannot withstand shrinkage or setting due to drying of the substrate.

Before installing a surface material, always make sure that the substrate structure is dry enough. The given drying times require a dry substrate, favourable drying conditions (approx. +20 ° C, RH 50%) and good ventilation. Pay special attention to the floor's humidity level with moisture-sensitive flooring materials.

To prevent the screed from too quick drying and cracking, the screed should not be exposed to draft, high temperatures or direct sunlight during the first 3 days after application.

Before turning on the underfloor heating, let the screed dry at least 1 mm / d (max. 30 mm thick levellings).

Water underfloor heating with accurate temperature control can be brought up to its operating temperature gradually after two weeks. Start by raising the temperature up to +15 °C or to floor's current temperature, if it is higher. After that, the floor temperature can be raised by 2 degrees every third day. If the room temperature is much lower than the temperature of the screed, the floor temperature must be raised slower.


 

Additional information

The information given in this product data sheet is based on our tests and our practical knowledge. The technical data is defined in standard conditions. Variations in local working conditions and methods will affect the product performance and result. The result is also strongly affected by working methods. We guarantee the high quality of our products according to our Quality Management System. No liability can be accepted from incorrect use of the product or prevailing conditions, over which we have no control. Thus, we cannot be held responsible for the final result. The correct use of the product presupposes that the user has made him/herself aware of the contents of the working instructions and procedure guide, if provided.

Environment and safety

Avoid unnecessary skin contact and exposure with the fresh product, use safety gloves. Refer to the material safety data sheet. For information on product and package disposal, visit www.kiilto.com.

Certificates
M1 emission classification for building material
LEED