Slate roof in Auderghem
Many houses in Auderghem have a slate roof — the historic material of the neighbourhood, found on the villas as well as on the townhouses around Val Duchesse. We've been looking after these roofs for more than 25 years: new installation, repair of broken or slipped slates, complete replacement of an old covering. For owners in Auderghem and its neighbouring communes, we come out quickly, with a 10-year workmanship guarantee.
What does slate roof work involve
A slate roof is a covering made of flat plates laid like scales, fixed to a timber structure. Depending on the age of the house and the budget, we work with natural slate (quarried, very strong, more expensive) or synthetic slate such as Cedral or Eternit, which costs less and also holds up well.
The work generally includes: removing the old or damaged slates, checking the underlay and battens, re-laying or fitting new slates, and checking the flashings and zinc junctions around chimneys and dormers. If the structure has moved or rotted, we say so: sometimes that's the real problem rather than the slates themselves.
When should you look after your slate roof
Some signals don't lie. A slate slipping or falling after a storm is visible. But other signs are less obvious: a damp patch on an upstairs ceiling, an under-roof that smells musty, slates starting to crack or flake. In those cases, better to look before the water damages the structure or the insulation.
A well-laid natural slate roof can last 80 to 100 years. Synthetic slate generally lasts 30 to 50 years depending on the brand and the quality of installation. When the covering passes 40 or 50 years without being touched, a check is due — not necessarily a complete replacement, but at least an eye on it.
Why slates get damaged
In Auderghem the winters can be harsh: frost, thaw, hail. Natural slate is hard, but not indestructible: one impact is enough to crack it. Fixing hooks rust over time and the slates end up slipping. The zinc junctions around chimneys and dormers age too, and that's often where the water gets in first.
Synthetic slate, for its part, can fade and become brittle after several decades. Some brands from the 80s-90s have aged badly. If your house has a roof from that era, it deserves a look.
There are also original installation errors: insufficient overlap between slates, nailing too tight which splits the plate. We sometimes see this on old roofs that were never reworked.
What makes the price of a slate roof vary
The price depends on several things, and there is no standard rate that fits every job.
The surface to cover obviously plays a role, but it's far from the only factor. Roof access counts a lot: a house with a steep, hard-to-reach roof takes more time and safety measures than an accessible one. The state of the structure and the underlay also shapes the quote: if battens need replacing or joists repairing, that's added.
The choice of material changes the budget significantly: natural slate costs more than Cedral or Eternit, but it also lasts two to three times longer. On a townhouse or villa, many owners choose natural slate to keep the original look.
Finally, if zinc work around chimneys or dormers needs doing at the same time, it's more economical to do everything in one pass rather than two separate interventions.
Repair or replace your slate roof
That's the real question, and we answer it honestly after seeing the roof. If a few slates are broken or slipped but the rest holds, a targeted repair is enough. No need to strip everything. We replace what's damaged, check the surroundings, and that's settled.
On the other hand, when more than a third of the slates are in poor condition, when the underlay is saturated with moisture or when the battens are too old to hold the hooks properly, a complete replacement is often more sensible in the long run. A partial repair on a tired covering is often patch-up work we'll have to redo within two or three years.
We tell you clearly what we see. No unnecessary work.
See also: Zinc work · Roof insulation · Roof repair
Frequently asked questions
What's the difference between natural slate and Cedral or Eternit slate?
Natural slate comes from a quarry: extracted, cut and laid as is. It's very heavy, very durable (often a century or more), and more expensive. Cedral and Eternit are fibre-cement synthetic slates: lighter, cheaper, with a lifespan of 30 to 50 years. Both are laid the same way and give a similar visual result. The choice depends on budget, house type and aesthetic requirements.
We have a leak but only a few slates are broken: is that serious?
A few broken slates can be enough for a leak to appear, especially in an exposed area or near a zinc junction. It's not necessarily serious if the repair is done quickly. The longer you wait, the more time the water has to seep into the underlay and the structure. The damage then becomes more expensive to repair.
What exactly does the guarantee cover?
We guarantee the workmanship for 10 years. For materials, the manufacturer's warranty applies and varies by brand and product. We explain both at quote time — no bad surprises afterwards.
Can insulation be fitted at the same time as redoing the slate roof?
Yes, and it's often the right moment. When the covering is open, access to the underlay is easier and the intervention costs are shared. If you have insulation grants available via Renolution (Brussels-Capital), it can change the economics of the project.
How long does a complete slate roof replacement take?
For a standard house in Auderghem, a complete replacement generally takes two to five days on site depending on surface and access. We give you the precise schedule before starting.