Silicone Hydrophobic Powder (SHP) is an advanced organosilicon-based additive designed to impart long-term water repellency to cement-based and gypsum-based building materials. With its excellent hydrophobic effect, moisture control capability, and durability enhancement, SHP has become an essential functional material in dry-mix mortars, wall putty, plasters, self-leveling compounds, and AAC block production.

In an industry where moisture silently undermines strength—from micro-capillary channels to surface carbonation—SHP acts like a quiet architectural “umbrella,” forming a stable, inward-facing shield that strengthens the integrity of the entire system.

1. Technical Mechanism of Silicone Hydrophobic Powder

Micro-scale Water Repellency

SHP is composed of finely processed silicone micro-powders with reactive siloxane groups.
When mixed into mortar:

• silicone particles disperse evenly

• hydrophobic sites orient toward the pore walls

• a permanent water-repellent network forms inside the matrix

This reduces capillary absorption and stops moisture from migrating into or through the material.

Breathable but Water-Resistant Structure

Unlike film-forming polymers, SHP does not create a surface coating.
Instead, it modifies the internal pore structure to achieve:

• high water resistance

• maintained vapor permeability

• reduced risk of blistering or peeling

This breathable hydrophobicity is essential for façade renders, skim coats, and repair mortars exposed to fluctuating climates.

Long-Term Stability

Once integrated with cement hydrates and mineral components, the siliconate-siloxane system becomes:

• UV resistant

• alkaline resistant

• ageing stable

Ensuring the water-repellent performance remains effective for years.

2. Performance Enhancements Brought by SHP

3. SHP in Construction Material Applications

Plasters & Renders

SHP helps façade and interior plasters resist moisture penetration while maintaining vapor permeability.
It prevents peeling, blistering, and mold development under humid conditions.

Wall Putty & Skim Coats

Adding SHP reduces moisture sensitivity and improves surface stability.
Walls stay smooth, clean, and resistant to dampness and staining.

Tile Adhesives & Waterproof Mortars

SHP reduces water absorption of cementitious adhesives, improving:

• adhesion retention

• dimensional stability

• resistance to substrate moisture vapor

Particularly suitable for humid or coastal regions.

Self-Leveling Compounds

Moisture absorption is minimized, improving flatness consistency and reducing micro-bubble formation during curing.

AAC (Autoclaved Aerated Concrete) Blocks

SHP is widely used in AAC block production to decrease water uptake and improve:

• handling strength

• storage stability

• long-term moisture resistance

AAC blocks containing SHP maintain lighter weight and higher thermal insulation value over time.

4. Synergy with RDP and HPMC in Dry-Mix Mortar Systems

With RDP (Redispersible Polymer Powder)

• RDP provides flexibility, adhesion, and toughness

• SHP provides internal hydrophobicity and moisture resistance

Together, they build mortars that are both durable and resistant to environmental moisture—ideal for façade plasters and ETICS basecoats.

With HPMC (Hydroxypropyl Methyl Cellulose)

• HPMC ensures water retention, workability, and consistency

• SHP prevents moisture-related performance decay after hardening

This synergy ensures stable construction during application and strong protection after curing.

Conclusion: SHP Enables Durable, Moisture-Resistant Building Materials

Silicone Hydrophobic Powder enhances building materials by reducing water absorption, preventing surface defects, improving freeze–thaw stability, and extending service life.
Its non-film-forming, breathable hydrophobic structure makes it indispensable in modern dry-mix formulations, especially in humid, coastal, or highly variable climates.

Our Commitment

We supply high-purity, stable-performance SHP produced with controlled siloxane modification technology.
Our technical team supports formulation optimization for:

• plasters

• putties

• tile adhesives

• waterproof mortars

• AAC block production

If you need reliable Silicone Hydrophobic Powder for high-performance construction materials, welcome to contact us.