OTTOSEAL S100 or S110 – which silicone for what?

The difference in one sentence: the curing system

S100 and S110 are both 1K silicone sealants, but they cure on different principles – and everything else follows from that. S100 is acetate-curing. According to the product description, this system adheres very well to ceramic substrates and is designed for excellent workability and smoothing – the classic sanitary case. S110 is neutral-curing on an oxime basis and MEKO-free. According to the manufacturer, it is non-corrosive towards unprotected metal surfaces and adheres without primer to glass, anodised and bare aluminium, rigid PVC and galvanised steel – which makes it the silicone for windows, facades and metalwork.

If you mix them up, you will notice later: a sanitary silicone on a bare aluminium window sill is the wrong choice, and conversely the construction silicone in the shower is technically possible (it is tested to EN 15651-3 for sanitary joints), but clearly at a disadvantage when it comes to smoothing and colour choice.

The candidates compared head to head

Sanitary specialist

OTTOSEAL S100 Premium Sanitary Silicone

Acetate-curing 1K silicone sealant, 300 ml cartridge. Fungicidal and bacteriostatic, very good adhesion to ceramic substrates, outstandingly smoothable surface.

• Complies with DIN 18545, Part 2, Group E
• Suitable according to IVD Data Sheet No. 3
• TOXPROOF from TÜV Rheinland: „particularly recommendable low-emission building product“
• More than 70 colours – from transparent and joint white to anthracite, bali and gold effect
• Shelf life at least 18 months when stored cool and dry

Suitable for: joints at showers, bathtubs, washbasins, worktops, tile connections, concrete and masonry.

View OTTOSEAL S100

All-rounder indoors & outdoors

OTTOSEAL S110 Premium Construction Silicone

Neutral-curing 1K silicone (oxime system), MEKO-free, 310 ml cartridge. For expansion and connection joints indoors and outdoors, with 25 % permissible total deformation.

• Tested to all four parts of EN 15651: facade, glazing, sanitary, pedestrian walkways
• ISO 11600 G 25 LM, highly abrasion-resistant and streak-free according to ift guideline VE-04/2
• Temperature-resistant from −40 to +180 °C
• Without primer on glass, anodised and bare aluminium, rigid PVC, galvanised steel
• EMICODE EC 1 Plus, VOC class A+, fungicidal; 40 colours

Suitable for: window and door connections, glazing rebate sealing, facades, metalwork, precast concrete and aerated concrete elements, glass blocks.

View OTTOSEAL S110

Detailed comparison table

All values come from the product descriptions and technical data in our shop. Where a field says „not stated“, we do not have a manufacturer value for it – that does not mean the property is missing. The complete technical data sheets can be found on the respective product pages.

Recommendation by application

What S110 cannot do – the limits stated openly

Because S110 is tested to all four parts of EN 15651, it seems like the universal silicone. The product description, however, names clear limits, and you should know them before buying:

• No natural stone. Marble and granite are excluded according to the manufacturer's primer table.
• Not paintable. It is paint-compatible according to DIN 52452, but cannot itself be painted over – why that is generally the case with silicone is explained in Painting over silicone.
• No full-surface bonding. S110 is a sealant, not an assembly adhesive.
• No contact with bitumen or plasticiser-releasing materials such as butyl, EPDM or neoprene.
• Yellowing possible: transparent and light colours can yellow over time in dark interiors.
• Insulating glass butt joints with a silicone edge seal need a special glazing silicone.
• Primer required on aerated concrete and clinker; for concrete, according to the data sheet, it depends on the individual case.

Application: what matters for both

Both silicones are applied between +5 and +35 °C and extruded with a manual, compressed-air or cordless gun. The bonding surfaces must be clean, grease-free, dry and sound: clean non-porous substrates with OTTO Cleaner T and a lint-free cloth (flash-off time approx. 1 minute), and mechanically remove loose particles from porous ones with a wire brush or grinding disc. In both cases, smoothing is done before skin formation – with S110 there are, according to the manufacturer, only about 10 minutes for this, so plan in short sections. Use Otto smoothing agent and a scraper; remove water streaks from the smoothing agent immediately with S110, otherwise streaks remain.

Two points that concern only S110: during application and curing, good ventilation is needed because small amounts of an oxime compound are released. And windows or doors may be assembled or packed no earlier than after 24 hours. A detailed step-by-step description can be found under Working with silicone.

The colour question

S100: more than 70 colours

S110: 40 colours

If the joint has to match the grout or the tile, S100 has the clear advantage – from joint white, chinchilla and manhatten to bali, cottofuge and anthracite. With 40 shades, S110 covers the typical building and window colours. An overview of the whole colour topic is given by our guide Silicone colours. You will find the complete construction silicone range in the category Construction Silicone & Window Silicone.

Frequently asked questions

Still unsure which product suits your connection? Give us a call: Baustoffheld, Lindenstrasse 56, 47623 Kevelaer, +49 (0) 2831 - 916 77 03.