01Clay roof tiles
02Roof build-up & insulation
03Fibre cement slates
04Natural slate
05Flat roofs
06More on the roof
Stormpan 44
Neutral, gently curved tile with a traditional shape. Wide range of fittings, removable and reusable. With a standard underlay, a minimum of 22°.
- Pieces per m²
- ± 20,7
- Minimum pitch with Fleece Premium
- 15°
Roof renovation from tile to insulation Roofs
Renovation from A to Z: structure, insulation, waterproofing and finishing. Whether it's a classic natural slate roof or a modern solution with ceramic tiles — we guide you from the site visit to handover.
10clay roof tile models by Koramic
4types of roof covering, flat roofs included
20 yearswarranty on our work
230 m²of natural slate in Andenne, laid in two weeks
DakpannenKeramische pannen, antraciet.
Underlay · DivorollWaterproof and vapour-open, with counter battens and tile battens.
Insulation · RecticelPIR insulation boards for maximum energy savings.
RaftersLoad-bearing structure checked, renewed where needed.Roof renovation from A to Z First look,
then choose.
During the site visit we inspect the roof structure, the underlay, the insulation, the rainwater drainage and the connections.
Project · Andenne
230 m²
Natural slate, 12 cm PIR insulation and new VELUX windows — laid in two weeks.
Roof renovation: a roof that works as one system From roof tile to insulation.
Clay roof tiles · Stormpan 4401 · Roof tiles by Koramic and Wienerberger Clay roof tiles: from the classic wave to the clean flat line
A good roof keeps the rain out and the heat in, and shapes how your home looks. Pick a model and see the tile and the roof — ten models from the Koramic and Wienerberger range.
Datura
Flat tile for a clean pattern on roof and façade. Five colours, also in matt glaze.
- Colours, also matt glazed
- 5
- Adjustable top interlock
- 37 mm
Nueva
Modern flat model with double side interlock and a wide top interlock — calm and quick to lay.
- Hanging nibs for stable fixing
- 2
- Side interlock, adjustable batten gauge
- 2×
OVH Klassiek
Classic wavy tile with a recognisable silhouette, in blue-grey, black and natural shades.
- Colour families: blue-grey, black, natural
- 3
- Hanging nibs, wide range of fittings
- 2
VHV Vario
Traditional character with modern fitting precision. Natural, engobe and glazed colours.
- Guaranteed side tolerance
- 6 mm
- Adjustable top interlock
- 20 mm
Standard
Historic model with ribs and interlocks. Straight or diagonal laying, in three colours.
- Pieces per m²
- ± 14,2
- Minimum pitch with Fleece Premium
- 15°
Oude Pottelbergse 451
Pantile with a historic silhouette and contemporary quality. In natural red, rustic and weathered Vieilli.
- Pieces per m²
- ± 18,6
- Minimum pitch with Fleece Premium
- 15°
Tegelpan Elfino
Flat extruded clay tile with a continuous bonding rib: an ultra-fine, contemporary look on roof and façade alike.
- Pieces per m², depending on batten gauge
- ± 28–30,2
- Minimum pitch with Fleece Premium
- 15°
Jura Nova
Large tile with a gentle wave, double side interlock and a flat trough — a clean character on large roof surfaces.
- Pieces per m²
- ± 9,7–11,3
- Minimum pitch with Fleece Premium
- 15°
Tradiva
Light tile with a gentle wave, deep interlocks and adjustable batten gauge — versatile, with a timeless wave line.
- Pieces per m²
- ± 12,5–14,1
- Minimum pitch with Fleece Plus (batten gauge 340 mm)
- 10°
Roof build-up & insulation · PIR / PUR02 · Roof insulation and roof build-up Roof insulation: warmth, dryness and ventilation — in the right order
A poorly insulated roof can waste up to 35% of your home's heat. A fully renovated pitched roof consists of four layers: the roof covering, the underlay, the insulation layer and a vapour control layer on the inside. Which insulation material we choose depends on the available height, the substrate and the roof covering.
PIR / PUR — maximum insulation at minimum thickness
With little spare height: ± 12 cm. Little height and a high thermal resistance needed? Then we combine PIR with glass wool.
- λ W/m·K
- 0,022–0,025
- Thickness
- ± 12 cm with little spare height
Glass wool — between the rafters, good for acoustics
Classic insulation between the rafters, with good sound damping.
- λ W/m·K
- 0,030–0,040
- Guide value
- 20–22 cm
Stone wool — increased fire resistance
For load-bearing structures and wherever fire safety matters most.
- λ W/m·K
- 0,032–0,040
Four layers, in this order
During the site visit we inspect the roof structure, the underlay, the insulation, the rainwater drainage and the connections. Only then do we choose the build-up. Gutters, roof windows and the connections to the chimney and façade are finished in the same job.
- Roof covering: tiles or slates
- Underlay: water and wind barrier, vapour-open
- Insulation layer
- Vapour control layer inside
Build-up height, the condition of the substrate and the chosen roof covering determine the final build-up — we check this for every project.
Fibre cement slates · TECTA Smooth03 · Fibre cement slates by Cedral Fibre cement slates: clean geometry or the character of natural stone
Fibre cement slates clad both roof and façade — one material. Pick a variant and see the slate, the roof and the colours.
TECTA Smooth — flat, matt, straight edges
For clean architecture with a flat, pure surface on roof and façade. UV-cured protective layer, colourfast and low-maintenance matt.
- Colour from the range
- Dark grey
Colours shown are indicative; make your final choice on a current Cedral sample.
TECTA Texture — relief and an authentic slate look
Textured finish, broken edges and a matt tone: the character of natural slate with the practical benefits of fibre cement.
- Colour from the range
- Dark grey
Colours shown are indicative; make your final choice on a current Cedral sample.
Alterna — roof and façade in one look
Smooth matt finish and straight edges for a calm, contemporary rhythm. In various formats, with square or chamfered corners.
- Colours from the range
- Dark grey · Metal grey · Pearl grey · Brick red · Evening rose · Light grey · Black · Crystal white · Dark brown
Colours shown are indicative; make your final choice on a current Cedral sample.
New Stonit — jagged edge, natural slate look
Relief, irregular slate edges and a matt finish for a warmer, more natural slate expression on roof and façade.
- Colour from the range
- Slate grey
Colours shown are indicative; make your final choice on a current Cedral sample.
Natural slate · Natural slate04 · Natural slate on roof and façade Natural slate: depth and texture you cannot imitate
Natural character, long service life, weather resistance and minimal maintenance — for projects where origin, texture and a timeless look matter. On pitched roofs and modern façades alike.
Natural texture · roof and façade in one line
Dark grey nuances, natural structure — for modern architecture and renovation.
- Natural colour nuances
- Dark grey · Blue-grey · Slate grey · Anthracite
Natural slate varies by quarry and by delivery; you choose the final shade on a real sample.
Expressive pitch
Dark surfaces emphasise geometry and connection details.
- Dark grey shades
- Natural texture
- Modern architecture
- Renovation
Flat roofs · Flat roof05 · Flat roof renovation Flat roofs: a flat roof that stands the test of time
Does your flat roof need renovating, or are you looking for a reliable solution for a new build? We supply durable, energy-efficient flat roof systems and take care of every detail — from high-quality insulation to perfect waterproofing.
Kessel-Lo · apartment building with flat roofs
Insulation and waterproofing for a long service life.
- Insulation
- PIR · λ 0.022–0.025 at minimum thickness
- Installation, repair and maintenance
- Modern materials for reliable waterproofing
- Room for installations, a roof garden or a terrace
New roof covering and finish
Renovation or new build: new roof covering, finish and insulation, also under a roof garden or terrace.
- Renovation
- New build
- Roof garden or terrace
More on the roof · Roof windows06 · Roof windows, solar panels, attic and roof cleaning More on the roof: light, energy and extra space
Each roof job explained separately: what it involves and what to look out for. Combine them with your new roof and everything happens in one schedule.
Roof windows — more light under the roof
New roof windows, included in the roof renovation. In Andenne we fitted new VELUX windows in a 230 m² natural slate roof.
Solar panels — integrated into the new roof
Also with a home battery, combined with your new roof.
Attic renovation
From attic to home office, lounge or extra bedroom.
Roof cleaning — roof and façade as good as new
Eco-friendly cleaning and protection: moss, deposits and dirt removed.
Projects Roofs we renovated.
From a terraced house in Niel to 230 m² of natural slate in Andenne. Every project is on the map.
26cities in 6 provinces
from Bruges to Namur
How we work How your renovation goes.
One fixed point of contact from the first question to handover. You know the price and the schedule in advance.
- 01Request
Fill in the form or call us. Within five days we schedule a free site visit.
- 02Site visit
Our specialist inspects the roof, façade or site, listens to your wishes and gives initial advice.
- 03Tailored quote
A clear proposal with price, schedule and options — no hidden costs.
- 04Agreement & schedule
Once you agree, we fix the schedule and prepare everything. Work starts within one to two months.
- 05Execution
Certified craftsmen work safely and efficiently, with as little disruption as possible.
- 06Handover & grants
We hand over the work and help with all the paperwork for grants, subsidies and inspections.
Free site visit · quote within 48 hours Tell us what
you want to renovate.
Our specialist visits free of charge, assesses your home and sends you a tailored, no-obligation quote within 48 hours.
- Phone
- +32 333 20 630
- leads@gravagroup.be
- Address
- Sneeuwbeslaan 14, 2610 Wilrijk
Free 3D visualisation with your quote