
Mapesil AC
Pure, mould-resistant, acetic silicone sealant with BioBlock technology, for sealing joints subject to movements up to 25%.
Supplied by SARP & LAB, the only authorised MAPEI distributor in Albania.
Where it is used
- Expansion, contraction and fillet joints subject to movement up to 25% of the initial size, according to EN 15651
- Flexible, waterproof seals between construction elements in building, mechanical engineering and manufacturing
- Sealing glass, ceramics, inox metal and certain types of plastic and rubber
- With Mapei Primerseal M or Mapei Primerseal A: concrete, wood, mineral substrates and oxidisable metals
- Interior or exterior use in dry, wet, humid or underwater environments, after complete crosslinking
Why Mapesil AC
- 48 colours from the MAPEI COLOURED GROUTS range, plus transparent
- High resistance to mould, with BioBlock technology
- Solvent-free and EMICODE EC1 Plus: very low emissions of volatile organic compounds
- CE marked to EN 15651-1, EN 15651-2, EN 15651-3 and EN 15651-4
- Impermeable to water and gases, with 800% elongation at break
- Produced without use of fossil resources, in a recycled cartridge; residual greenhouse gas emissions offset for the year 2026
How it is applied
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Prepare the joint
Surfaces must be dry, solid and free from dust, loose particles, oils, grease, wax, old paint and rust. Size the joint so that the product does not extend more than 25% of its initial width (calculated at +20°C).
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Set the depth
The sealant must bond only to the side walls, not to the bottom: use Mapefoam closed-cell polyethylene foam cord. Sealant depth is 5 mm in a 5 mm joint, 10 mm in joints 10 to 20 mm wide, 15 mm in a 30 mm joint and 20 mm in joints 40 to 50 mm wide.
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Prime where needed
Brush Mapei Primerseal A or Mapei Primerseal M onto the relevant areas of the joint and leave to dry. Under severe conditions such as immersion, soaking or high movements, an appropriate primer is strongly recommended: contact Mapei Technical Assistance.
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Apply
Cut the cartridge above the end of the thread, screw on the nozzle and cut it at 45° to suit the joint. Insert the cartridge into the gun and extrude.
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Finish the surface
Before the surface film forms, finish with a tool (e.g. Mapei Perfect Seal) moistened with UltraCare Smooth Silicone by MAPEI. Alternatively, smooth dry after protecting the joint edges with adhesive paper masking tape, and remove the tape immediately after finishing.
Technical data
| Classification (EN 15651-1) | F-EX-INT-CC, class 25 LM |
| Classification (EN 15651-2) | G-CC, class G 25 LM |
| Classification (EN 15651-3) | S, class XS 1 |
| Classification (EN 15651-4) | PW-EX-INT, class 12.5 E |
| Maximum movement allowed | 25% (EN 15651-1, EN 15651-2) · 12.5% on floors (EN 15651-4) |
| Recommended application temperature | from +5°C to +50°C |
| Time to form surface skin | 10 minutes (at +23°C, 50% R.H.) |
| Speed of vulcanisation | 4 mm in 1 day, 10 mm in 7 days |
| Tensile strength (ISO 37) | 1.6 N/mm² |
| Elongation at break (ISO 37-3) | 800% |
| Shore A hardness (ISO 868) | 20 |
| Consumption | 10 x 10 mm: 100 ml per metre (3.1 m per cartridge) · 20 x 10 mm: 200 ml per metre (1.6 m per cartridge) |
| Packaging | 310 ml recycled plastic cartridges, boxes of 12 |
| Storage | up to 24 months in original cartridges, in a dry and clean place |
Source: MAPEI technical data sheet 8139-10-2026; typical values. Check the current data sheet before use. Product page at MAPEI
Application precautions
- Do not use on surfaces sensitive to acids such as limestone: use a specific neutral silicone sealant, e.g. Mapesil LM or Mapesil Stone Matt
- Not recommended on highly plasticised materials or bituminous surfaces
- Do not use to seal aquariums
- For floor joints subject to heavy traffic, use a polyurethane sealant (e.g. Mapeflex PU 45 FT) or the epoxy-polyurethane Mapeflex E-PU 21 SL
- Outdoors, light surface dirt may build up, though it is easily washed off by rain
- Avoid contact between unpolymerised sealant and any solvent, which can delay or inhibit crosslinking
Product for professional use.
Our projects with Mapesil AC
Frequently asked questions
How many metres does a cartridge cover?
It depends on the joint. A 310 ml cartridge gives 12.4 m at 5 x 5 mm, 3.1 m at 10 x 10 mm, 1.6 m at 20 x 10 mm and 0.7 m at 30 x 15 mm. As a fillet joint it gives 24.8 m at 5 mm and 6.2 m at 10 mm.
Which surfaces does it bond to without primer?
Glass, ceramics, inox metal and many types of plastic; preliminary tests are advisable because plastics vary widely. Concrete, wood, mineral substrates and oxidisable metals need Mapei Primerseal M or Mapei Primerseal A.
Can it be used on limestone?
No. Surfaces sensitive to acids, such as limestone, need a specific neutral silicone sealant, e.g. Mapesil LM or Mapesil Stone Matt.
Can it be used outdoors or under water?
Yes. After complete crosslinking it is suitable for interior or exterior use in dry, wet, humid or underwater environments. For immersion, an appropriate primer is strongly recommended. Do not use it to seal aquariums.
How long does it take to cure?
At +23°C and 50% R.H. a skin forms in 10 minutes, and vulcanisation reaches 4 mm in 1 day and 10 mm in 7 days. The speed depends mainly on atmospheric humidity and only slightly on temperature.
Is there a warranty?
If required, MAPEI can provide a warranty for each product it sells. Contact us about your case.


