Description
Mapei Mapesil LM Natural Stone Silicone is a neutral, solvent-free, low-modulus silicone sealant with BioBlock mould-resistance technology, formulated specifically for materials sensitive to acids and plasticising agents — marble, granite, sandstone and quartz among them. Its low modulus of elasticity is what genuinely protects these delicate materials, deterring surface bleeding and the migration of plasticisers that would otherwise cause visible staining at the joint edge with a standard sealant.
Rated for movement in service up to 25% with a modulus of elasticity at 100% elongation of just 0.35 N/mm², it suits genuinely demanding internal and external fillet and expansion joints — between pre-fabricated panels, window and door fittings, pipework and vertical walls, and floors with limited pedestrian traffic. It bonds well without a primer on most substrates used in the building industry, including glass, ceramic, marble, aluminium, concrete and stainless steel, and complies with EN 15651 across façade, glazing, sanitary and pedestrian walkway sealant standards.
Available in 10 colours — from 100 White through to 700 Translucent and 130 Jasmine — it gives real flexibility to match a wide range of natural stone tones. Its odourless, thixotropic paste consistency applies cleanly on both vertical and horizontal surfaces, curing at room temperature through atmospheric humidity to form a genuinely stable, flexible seal that stays reliable through inclement weather, temperature variation and industrial environments.
Technical Specifications
| Formula | Neutral cure, solvent-free, low-modulus silicone with BioBlock technology |
|---|---|
| Colour | 10 colours: White, Manhattan, Silver Grey, Medium Grey, Cement Grey, Anthracite, Black, Jasmine, Beige, Translucent |
| Size | 310ml cartridges, individual or boxes of 12 |
| Movement in service | Up to 25% |
| Shore A hardness | 21 |
| Service temperature | -40°C to +150°C |
| Emission rating | EMICODE EC1 Plus — very low emission |
| Shelf life | 18 months, dry cool place, original cartridges |
Where to Use
- Marble, granite, sandstone and quartz joints
- Brick, cellular concrete and varnished or enamelled wood
- Internal and external fillet and expansion joints with high movement
- Floors with limited pedestrian traffic
How to Apply
- Prepare joints — solid, dust-free, clean of oil, grease, wax and old paintwork.
- Mask the edges — apply masking tape to protect the substrate from staining.
- Backfill deep joints — insert Mapefoam polyethylene foam cord to control bond depth.
- Apply with an extrusion gun — cut the cartridge tip at 45° according to joint width.
- Finish the surface — use a damp tool, ideally dipped in soapy water, before the skin forms.
Important Notes
- Do not apply on rubber, heavily plasticised plastics or bitumen.
- Do not use for sealing floors subject to intense traffic — use Mapeflex PU45 FT or E-PU21 SL instead.
- Never apply below 0°C.
