• Low modulus neutral cure formula that flexes with movement joints instead of cracking
• Primerless adhesion to most construction materials, so less prep on site
• Permanently flexible for up to 25 years
• Neutral cure, so it will not corrode metals or stain natural stone and mirrors
• Weatherproof for sealing around doors and windows, inside or out
• Certified to EN 15651-1 (F EXT-INT) and CE marked
• Five colours and a single cartridge or trade box of 25

First, make sure the joint faces are clean, dry and free from dust, grease and any old sealant. For deep joints, pack a backing rod in first so the silicone bonds on two faces only.

Next, cut the nozzle to the joint width at 45 degrees and apply with a standard sealant gun such as our Economy Sealant Gun. Work the gun steadily to fill the joint without trapping air.

Then tool the bead within about 10 minutes, before it skins, using a wetted spatula or our Sealant Applicator Tool Kit. Because it is neutral cure, it is safe on mirrors, coated metals and natural stone.

Finally, leave it to cure fully before exposing the joint to heavy rain. If you need a sealant you can paint over, choose Super-Mate instead, and for bathrooms and wet rooms use Xtreme anti-mould silicone.

• Product codes: BDUWH, BDUBL, BDUBR, BDUGR, BDUT
• Type: low modulus neutral cure (LMN) silicone sealant
• Colours: white, black, brown, grey and translucent
• Movement: low modulus, for working joints with movement
• Durability: permanently flexible for up to 25 years
• Standards: EN 15651-1, F EXT-INT, CE marked
• Cartridge: EU3 (approx. 300 ml)
• Application temperature: +5 °C to +40 °C
• Pack sizes: single cartridge or trade box of 25

What is the difference between neutral cure and acetoxy silicone?

Neutral cure silicone like Ulti-Mate has almost no smell, will not corrode metals and will not crack natural stone. Acetoxy silicone (such as our Multi-Mate) smells of vinegar as it cures and is better kept to glass and glazed tiles. For construction and exterior joints, choose neutral cure.

Can I paint over Ulti-Mate?

No. Like most low modulus silicones it will not hold paint reliably. If you need to overpaint the joint, use Super-Mate siliconised acrylic sealant instead.

Is it suitable for bathrooms and wet rooms?

It seals well, but for showers, baths and other damp areas we recommend an anti-mould silicone such as Xtreme or S3 Sanitary, which contain a fungicide to resist black mould.

Will it stick without a primer?

Yes. Ulti-Mate has primerless adhesion to most common building materials. Surfaces still need to be clean, dry and sound.

Can I use it on mirrors?

Yes, because it is neutral cure it will not attack the silvering. For dedicated mirror fixing on a wall, our Glass-Mate mirror adhesive is purpose made.

How long does it take to cure?

It skins in around 10 minutes and cures at roughly 2 to 3 mm per 24 hours, so deeper joints take longer. Let it cure fully before heavy weather.

Inside or outside?

Both. It is certified F EXT-INT, meaning it is rated for exterior and interior facade joints.

Do I need the whole box?

No. Buy a single cartridge for a one-off job, or the trade box of 25 if you are sealing all day.