How often does a facade's water repellent need to be renewed?

It depends on exposure, but it's worth checking every few years to see whether water still beads on the surface.

Water Repellents for Facades, Terraces, and Showers: The Fila Guide

Q: Can a water repellent be applied over a wall with mold?

Not over active mold: it must first be removed and then the water repellent applied as prevention.

Quick answer: a water repellent protects facades, terraces, and outdoor surfaces from water without blocking the material, so it keeps breathing. It's the best prevention against water infiltration, mold, algae, efflorescence, and frost damage. The Fila range covers everything from a basic water repellent to a consolidating anti-infiltration treatment for cracked terraces, plus specific solutions for showers.

Which water repellent to choose

Product	Best for	Key features
Hydrorep Eco	Facades and exterior walls	Certified anti-algae barrier (UNI EN ISO 846), UV-resistant
HYDROREP	Slate, sandstone, quartzite, limestone, granite, and cement	Protects grout and prevents mold, moss, algae, and rust stains
Concrete Hydro	Cement and mortar	Consolidates and prevents surface dusting in addition to repelling water
PRW200	Before grouting on absorbent materials	Protects against grouting residue without affecting grout adhesion
Salvaterrazza	Terraces, roof terraces, balconies, and roofs	Consolidating treatment that seals cracks from 0.5 µm to 1 mm
Salvaterrazza® Eco	Terraces and horizontal and vertical exterior surfaces	Water-based version, penetrates the material and grout
Fila Salvadochia	Showers and shower trays	Prevents efflorescence in grout lines and slows aging in humid environments

From surface protection to structural repair

Simple water repellent (Hydrorep, HYDROREP): repels surface water, protects against mold and frost.
Consolidating water repellent (Concrete Hydro, Salvaterrazza): in addition to repelling water, it compacts the material and prevents it from crumbling (surface dusting), ideal if the substrate is already somewhat deteriorated.
Pre-grouting (PRW200): applied before the installation stage, not after.

Before applying a water repellent

The surface must be clean and completely dry. If there's construction dirt, remove it first (see the construction site cleaning guide).
If there's residue from a previously misapplied waterproofing product, strip it first with Fasezero.
Apply the water repellent with a brush, roller, or sprayer, avoiding pooling and direct sunlight.
Let it dry for the recommended time before exposing the surface to rain.

Frequently asked questions

Does a water repellent make the surface 100% waterproof?

It repels rainwater and surface moisture, but it doesn't replace structural waterproofing on roofs with serious infiltration problems; in that case, a consolidating treatment like Salvaterrazza is a better fit.

Can a water repellent be applied over a wall with mold?

Not over active mold: it must first be removed with a specific product, and then the water repellent applied as prevention. See the anti-mold and anti-algae guide.

How often does a facade's water-repellent treatment need to be renewed?

It depends on orientation and exposure, but as a general reference it's usually checked every few years, verifying whether water still beads on the surface.