I. Scope

This document provides recommended practices for the inspection, cleaning, and maintenance of silicone sealants used in:

  • Exterior building applications: glazing, curtain walls, claddings, perimeter sealing, construction joints, etc.
  • Interior wet areas: showers, toilets, bathtubs, kitchens, laundries, etc.

Regular maintenance ensures long-term performance, water tightness, and aesthetic integrity.

II. Product Types and Applications

Sealant
Type

Applications

Key
Properties

Hypersil
911

General purpose glazing, curtain walls, construction joints, building cladding, etc.

100% Silicone, UV stable, Flexible

Hypersil
912/Matt

Sealing damp and steamy areas, wet areas, kitchens and laundries, stainless steel benches

100% Silicone, Mould or mildew resistant, Sanitary grade

Hypersil
Facade
100

High‑movement joints in glazing, cladding, weather sealing, and general joint applications.

100% Silicone with a ±50% movement capability (100% total).

Stonesil

Natural stones for wet (showers, bathtubs, kitchens etc.) and dry areas

100% Silicone, Non-bleeding property, Stone safe, No migratory staining

 

III. Inspection Guidelines

Regular inspections help detect early signs of sealant deterioration and prevent failure.

Recommended Frequency:

  • Exterior Applications: Every 12–24 months
  • Interior Wet Areas: Every 6–12 months

Look for:

  • Loss of adhesion (detachment from substrate)
  • Cohesive failure (cracks or splits in sealant body)
  • Discolouration or mould growth
  • Surface hardening, shrinking, or softening
  • Water ingress or leakage signs

IV. Cleaning Recommendations

Application
Area

Cleaning
Method

Things
to
Avoid

Exterior
Joints

Mild detergent with soft cloth or sponge. Rinse with clean water.

Harsh solvents, pressure washers, abrasives

Wet
Areas

pH-neutral bathroom cleaner. Wipe regularly to prevent mould. Rinse and dry after cleaning.

Bleach, ammonia, steel wool or brush, acid cleaners


V. Maintenance of Silicone Sealant Joints – Exterior and Interior Wet Area Applications

The upkeep of silicone sealant joints typically involves routine inspections and localised repairs when necessary. It’s also important to ensure that the surrounding construction materials remain in good condition, particularly in areas such as exterior and glazing systems.

One category of joints that requires special attention is sanitary joints, found in wet areas such as bathrooms, kitchens, food processing facilities, etc. These areas generally use sanitary-grade silicone sealants, which are formulated with fungicidal additives to improve resistance against mould and mildew.

However, the effectiveness of these fungicides can diminish over time, especially when exposed to harsh cleaning agents. Chlorine-based cleaners can neutralise the fungicidal properties, compromising the sealant’s resistance to fungal growth.

For sealants used in wet areas, the following maintenance practices are recommended:

  • Ensure the space is adequately ventilated to manage humidity levels.
  • Avoid using strong or aggressive cleaners on the sealant joints to preserve the integrity of the fungicide.

VI. Repair Procedure

  1. If sealant is damaged, contaminated, or detached:
  2. Remove old sealant completely using a knife or sealant remover.
  3. Clean substrate—ensure dry, dust-free, oil-free, and mildew-free surface.
  4. Prime if required (Consult Pasco Technical Department).
  5. Apply new compatible silicone sealant.
  6. Tool the joint smoothly and allow full curing (cure time: 10mm @ 25°C is 5-7 days)

Note: Ensure compatibility between old and new sealants if over-sealing.

VII. Preventative Measures

  • Use proper ventilation in wet areas to reduce moisture buildup.
  • In wet areas ensure adequate routine cleaning of the silicone using a pH neutral cleaner.
  • Install backer rods in deep joints to control joint depth and adhesion.
  • Avoid water ponding or prolonged saturation on external joints.
  • Ensure proper joint design for anticipated movement.

VIII. Limitations

  • Silicone is not paintable.
  • Do not apply on wet, contaminated, or frozen surfaces.
  • Mould-resistant silicone delays but does not prevent mould growth without proper ventilation.
  • Not suitable for submerged joints unless specifically formulated.

IX. Health & Safety

  • Always refer to the product Safety Data Sheet (SDS) before handling.
  • Use gloves and ensure adequate ventilation during application and curing.
  • Dispose of old sealant and cleaning materials in accordance with local regulations.

Disclaimer: This document has been prepared based on Pasco’s current knowledge and experience of Pasco’s products when properly stored, handled and applied under normal conditions. It only applies to the application and product referred to in this letter. In case of changes in the parameters of the application, such as changes in substrates etc., or in case of a different application, consult Pasco’s Technical prior to using Pasco’s products. The user of the product must test the product’s suitability for the intended application and purpose. Consult the current technical data sheet. Except as expressly stated in writing, Pasco’s warranty is governed exclusively by our current sales conditions. Pasco does not warrant the correct application of its product.