Technical Information:

• Full Pallet Deal: 39 x 25KG bags
• Self-Levelling
• Up to 25mm in a single application (4-25mm when pumped) 
• Fast drying – apply moisture sensitive finishes after 24 hours
• Protein-free
• Foot traffic in 2 - 4 hours | Full Track & Coverings after 1-2 days
• BS EN 13813 CT – C30 – F7
• Packaging: 25kg multi-wall, extra strength paper bags
• Storage: Store in unopened containers away from damp & drafts
• Shelf Life: 6 months in unopened packaging
• Coverage: 25 kg will cover 1m2 @ 12.5mm
• Do not use on flexible surfaces and cannot be used as a final wearing surface.

How do I prepare to apply Larsen SLC 1550?

The building should be weather-tight prior to the application of any screed materials. The roof, external doors and windows must be in place, closed or covered, and they must be taped to prevent any draughts. The substrate must be structurally sound concrete or screed and must be thoroughly clean, dry, and free from dirt, debris or dust which may impair adhesion. Suitable mechanical preparation of substrate may be required. Air and substrate temperatures must be greater than 5oC. Relative Humidity value of the floor must be less than 75% when moisture sensitive finishes are to be laid onto the SLC 1500.

Do I need to prime or use a DPM ahead of applying SLC 1550?

Normal concrete and screed requires priming with an acrylic primer, diluted 1:1 with clean water. For particularly porous concrete and screed, we recommend priming with an acrylic primer diluted 1:1 with clean water followed by another coat of acrylic primer applied neat. Please note that if the relative humidity value of the floor is greater than 75%, Larsen DPM should be used. Apply two coats of DPM as directed with the dry sand (0.7 -1.2mm) scatter into the wet second coat at a rate of 2 kg/m2 (with the excess removed by vacuuming). For thickness of >25mm or heavy traffic areas, ring us for advice.

How do I mix Larsen SLC 1550? 

1. Simply add 4.75 to 5.25 litres of clean water to a bucket
2. Add a 25kg bag of SLC 1550
3. Mix with a heavy duty drill and paddle for 1-2 minutes or with a suitable continuous mixer-pump.

Important: Do not add more than 5.25 litres of water for each 25KG bag, as excess water will cause a loss of strength in the product.

How do I apply Larsen SLC 1550?

Once the required consistency of SLC 1550 is achieved, pour or pump apply the mixed product over the sub-floor. SLC 1500 will self-level into smooth finish. Where necessary, release any air bubbles in the product with a trowel or spiked roller, this must be carried out within 5 – 10 minutes of application. SLC 1500 can be applied up to 25mm (min 4mm when pumping). For thickness of >25mm, consult us for advice.

Once applied the screed must be protected from draughts for the the first 6 hours to allow the SLC 1550 to cure, we always advise taping up doorways and windows with polythene. After the 6 hour period, then ensure the room has sufficient ventilation to allow the screed to fully dry out. SLC 1500 can receive foot traffic after 2 - 4 hours, and floor coverings can be installed after 24 - 48 hours depending on thickness of SLC 1500, substrate and site conditions. If any trowel marks remain, remove with a wet trowel after 1-1½hrs.