Larsen SLC 1550 Flex Self Levelling Compound – Universal Renovation Screed extended information
Coverage: 20kg will cover approximately 3m2 @ 5mm
Preparation
The building must be weather tight prior to the placing of any screed material: the roof, external doors and windows must be in place and closed or covered and taped to prevent draughts. All substrates must be suitable to receive the screed as per current good working practices. The substrate may be structurally sound concrete or screed; suitable timber; ceramic tiling; or existing resilient flooring. It must be thoroughly clean, dry and free from laitance, grease, oils, paint or other contaminants which may impair adhesion. Suitable mechanical preparation of substrate may be required. Air and substrate temperatures must be greater than 5°C. Relative Humidity of the floor must be <95% generally and <75% when moisture sensitive finishes are to be laid (if >75%, Larsen DPM should be applied to the substrate).
Existing movement joints should be carried through the Larsen SLC 1550 FLEX, preferably with proprietary joints. When applying over underfloor heating a suitable 10+mm PE foam expansion strip should be fitted the full depth of screed around the entire perimeter of the floor. In some instances it may be necessary to incorporate a glass fire reinforcing mesh in the screed, consult Technical Department for advice.
Priming
Normal concrete/screed requires priming with Larsen Acrylic primer diluted 1:1 with clean water. Particularly porous concrete/screed requires priming with Acrylic primer diluted 1:1 with clean water followed by a coat of Larsen Acrylic Primer applied neat. Relative Humidity of the floor must be <95% generally and <75% when moisture sensitive finishes are to be laid (if >75%, Larsen DPM should be applied to the substrate). Timber floors must be free from deflection and be suitably stable. Existing floorboards should be overlaid with minimum 15mm moisture resistant plywood, screw fixed at 300 mm centres. OSB may be used on floors, but must be flooring grade, rigid and screw fixed at 300mm centres. The surface should be sanded to remove any wax or similar treatment and then primed. WBP plywood may be used but due to the variability in quality, extra care should be taken. It is recommended that WBP sheets are sanded and primed. Edges of all timber sheets should be supported by joists or studs and where possible timber sheets should be tongue and groove. In wet areas timber should be suitably tanked. All timber substrates should be primed with one coat of Larsen Acrylic Primer applied neat. Allow primer to dry to a transparent tacky film before applying Larsen SLC 1550 FLEX.
Mixing
Add 3.75 -4.25L of clean water per 20kg bag to achieve target flow of 215-230mm without bleed or settlement. Mix with a heavy duty drill and paddle for 1-2 minutes or with a suitable continuous mixer/pump. Excess water will cause a loss of strength.
Application
Pour or pump the mixed product over the floor. Larsen SLC 1550 FLEX will level out to a smooth finish. Where necessary, release air bubbles with a trowel or spiked roller. This practice must be carried out within 5 – 10 minutes of application. SLC 1550 FLEX can be applied up to 50mm (minimum of 3mm). For thickness >30mm consult Technical Department for advice. The screed must be protected from draughts within the first 6 hours, if necessary open doorways and windows should be closed using tape and polythene
Subsequently, ensure the room has sufficient ventilation to allow the screed to dry out. After installation protect the screed from following trades. SLC 1550 FLEX will accept foot traffic after 2 – 4 hours. Floor coverings can be installed after 24 – 72 hours depending on thickness of Larsen SLC 1550 FLEX, substrate and site conditions. Should any trowel marks remain, remove with a wet trowel after 1-1½hrs.
Restrictions
Larsen Professional SLC 1550 FLEX is not suitable for industrial use and cannot be used as a final wearing surface. Larsen Professional SLC 1550 FLEX should not be applied to flexible surfaces or surfaces subject to vibration. All substrates must be suitable for the intended dutv and traffic without excessive deflection. All substrates must be sufficiently strong and stable to bear the weight of screed and covering. Prof SLC 1550 FLEX is suitable for use over underfloor heating systems. Room and substrate temperatures should be above 5°C during application.
Larsen SLC 1550 product information
FORM: | Powder |
COLOUR: | Grey |
HAZARD INFORMATION: | IRRITANT contains cement - Consult Safety Datasheet before use |
CLEANING: | Clean tools, equipment etc. using warm water. Mechanical means are necessary when the product has set. |
PACKAGING: | 20kg multiwall, sealed paper sacks |
STORAGE CONDITIONS: | Store in sealed containers in dry conditions, protected from extremes of temperature |
SHELF LIFE: | 6 months in unopened manufacturer's packaging |
Larsen SLC 1550 application information
MIX PROPORTIONS: | Mix 20 kg pack with approx. 4L water |
POT LIFE: | Approx. 30 minutes @ 20°C |
APPLICATION TEMPERATURE: | +5°C to +30°C |
BED THICKNESS: | 3 - 50mm (min 10mm when using reinforcing mesh) |
TIME TO TRAFFIC: | Light Foot Traffic - after 2 - 4 hours Full Traffic - after 1 - 2 days Covering - after 1 - 3 days (depending on depth and site conditions) |
COVERAGE: | Approx 2.5 - 3m2 / 20kg pack @ 5mm |
Larsen SLC 1550 performance information
SHRINKAGE | <0.06% |
COMPRESSIVE STRENGTH | ≥25MPa |
FLEXURAL STRENGTH | ≥7MPa |
CLASSIFICATION: | EN13813 - CT-C25-F7 |
kennythefloorer –
Can’t go wrong with larsen slc 1550. Never fails me. Great product
kennythefloorer –
davetiler –
My go-to levelling compound and never had an issue, 5 stars!
davetiler –