Why choose Avenir Renovations?
Why redo the waterproofing of your roof?
1. Avoid infiltrations and interior damage
Poor waterproofing can lead to:
- Water infiltrations
- Stains on ceilings and walls
- Mold, efflorescence
- Weakening of insulation and the framework
Redoing the waterproofing allows for restoring an effective protective barrier against the elements.
2. Preserve energy performance
A failing roof can lead to significant thermal losses, especially in winter. By ensuring good waterproofing against water and air, you improve the overall insulation of your building and reduce your heating bills.
3. Preserve the structure of the building
Prolonged infiltrations can weaken the framework, load-bearing walls, or floors. Timely intervention can prevent heavy and costly work in the long term.
Steps for roof waterproofing renovation
In Belgium, the renovation of roof waterproofing takes place in 4 steps: diagnosis, preparation, installation of the waterproofing system, and final inspection.
Signs of a failing roof waterproofing
- Signs of moisture on ceilings or walls
- Peeling paint or wallpaper
- Mold in the attic or under the roof
- Visible infiltration during rain
- Bad smell or persistent feeling of dampness
- Broken tiles, missing slates, degraded membranes
Price to redo the waterproofing of a roof in Belgium
The cost of waterproofing renovation depends on the type of roof, the technique used, the area to be treated, and the condition of the substrate. Here are the factors to consider and the prices generally practiced.
Factors influencing the price
- Type of roof: flat, sloped, accessible terrace or not
- Area to cover: decreasing rates for large areas
- Condition of the existing roof: need for removal, treatment, remediation
- Type of material: bitumen, PVC, EPDM, liquid waterproofing
- Site accessibility: scaffolding, slope, height, neighboring properties
- Desired finish: gravel, slab, possible vegetation
Average observed price (including VAT, supplies and labor)
| Type of service | Average price per m² |
| Single-layer bitumen waterproofing | 45 € to 65 € / m² |
| EPDM or PVC membrane | 60 € to 90 € / m² |
| Liquid waterproofing (resin) | 70 € to 100 € / m² |
| Partial roof replacement + waterproofing | 90 € to 140 € / m² |
| Diagnosis with moisture or infiltration test | Free during on-site estimate |
On which roofs can we intervene?
- Pitched roof (tiles, slates, steel trays, sandwich panels)
- Flat roof (bitumen, PVC membrane, EPDM, multilayer)
- Green or technical roof
- Annexes, garages, extensions, industrial buildings
Our teams work on both individual houses and collective or commercial buildings, in complete renovation or partial refurbishment.
Roof waterproofing techniques used
| Type of waterproofing | Common applications |
| Bituminous waterproofing (SBS or APP) | Flat roofs, accessible terraces, old substrates |
| PVC or TPO membrane | Flat roofs, lightweight, seamless, hot air welded |
| EPDM membrane (rubber) | High durability, maintenance-free, ideal for flat or inverted roofs |
| Under-roof screen (HPV film) | Under tiles or slates, protects the framework from infiltration |
| Liquid waterproofing (SEL) | On balconies, terraces, technical areas, complex or renovated shapes |
We select the most suitable technical solution for the nature of your roof, its accessibility, its use, and your budget.
Why choose Avenir Rénovations Belgium?
- Free technical diagnosis
- Waterproofing solutions tailored to each type of roof
- Technicians trained in EPDM, bituminous, and liquid systems
- Ten-year warranty on waterproofing work
- Compliance with Belgian standards for ventilation, insulation, and safety
- Project monitoring with a dedicated contact person
Request your free quote to redo the waterproofing of your roof
Have you noticed an infiltration, degradation, or do you want to prevent damage related to humidity? The refurbishment of waterproofing is an essential operation to ensure the health of your home and maintain your comfort.
Contact Avenir Rénovations Belgium today for a free technical study and receive your detailed quote without obligation.
Frequently Asked Questions – Roof Waterproofing in Belgium
How can I tell if my roof's waterproofing is failing?
Several signs may indicate a waterproofing problem:
- Appearance of moisture stains on ceilings
- Mold in attics or under slopes
- Visible infiltrations during heavy rain
- Tiles, slates, or membranes torn or displaced
- Persistent bad odor in certain rooms
A site diagnosis allows for precise localization of leaks and proposing a suitable solution.
What is the difference between bituminous, EPDM, and PVC membranes?
- The bituminous membrane (SBS or APP) is a classic and economical solution, installed hot, with good durability over time.
- The EPDM membrane is a synthetic rubber, very durable (up to 50 years), flexible, and UV resistant, ideal for flat roofs.
- The PVC or TPO is a thermoplastic membrane, lightweight, welded with hot air, often used for large industrial surfaces or lightweight flat roofs.
The choice depends on the use of the roof, the expected durability, and the budget.
Can waterproofing be redone without removing the old layer?
In some cases, yes. If the existing membrane is stable, it is possible to install a new layer in overlay. However, this solution is only feasible if the structure is sound, without trapped moisture or deformation. A technical assessment is essential before deciding.
How long do waterproofing works take?
For an average-sized roof (30 to 100 m²), expect generally 1 to 3 days of work, depending on:
- The condition of the substrate
- The technique used
- The weather conditions
- The accessibility of the site
Is it mandatory to insulate during a waterproofing refurbishment?
No, but it is highly recommended. Redoing the waterproofing is often the ideal opportunity to integrate external thermal insulation, especially on flat roofs. This helps to meet PEB standards and reduce heat loss. Some financial aids may be available in Wallonia, Brussels, or Flanders.
