
Roof insulation
in Nivelles
The old centre imposes colour and material constraints, so we always check before ordering a roof covering. That is why roof insulation comes back so often in our schedule in Nivelles.

The context in Nivelles
Why here in particular
The old centre imposes constraints on colour and material: we always check before ordering roof covering. So we adapt the equipment and the method rather than running a standard protocol.
In Belgium, 25 to 30 % of the heat lost from an uninsulated house goes out through the roof. But roof insulation fitted without a continuous vapour barrier and without an air gap simply moves the problem: the vapour condenses in the wool and the roof timbers take in water.
- Quote
- Priced after a site visit, free of charge and with no obligation.
- Duration
- 1 to 4 days depending on the surface area and the layout.
- Call-out
- Included in Nivelles and neighbouring municipalities
How it runs
How the job runs
The same protocol everywhere, adapted to what the visit reveals on site. Nothing is decided from the pavement.
- Survey and calculation of the thicknesses
- Mineral wool or cellulose insulation
- Continuous vapour barrier and tapes
- Treatment of penetrations and openings
- Keeping the air gap
- Removal of offcuts
Site assessment
Available thicknesses, roofing underlay present or not, existing ventilation.
Preliminary treatment
Sound roof timbers before insulating. We never cover over attacked timber.
Fitting the insulation
Mineral wool between and under the rafters, or blown onto the loft floor.
Vapour barrier
Continuous membrane, overlapping strips, tape on every penetration.
Ventilation
Air gap kept under roof covering. That is what prevents condensation.
Frequently asked questions
Roof insulation in Nivelles
The questions we get asked most often before this kind of job.
And without roofing underlay?
There needs to be a ventilated air gap under the roof covering, or you fit an underlay. Without it, the insulation takes on water the first winter.
Are there any grants?
Depending on the Region and the period, yes, often tied to a minimum thickness and a registered installer. We tell you where to check rather than promising you an amount.
Cellulose or wool?
Blown cellulose for an uneven loft floor, board wool for a slope between rafters. Thermal lag is what counts in summer.
Do you come out to Nivelles with no extra call-out charge?
Yes. Nivelles is one of our 17 municipalities: the call-out is included in the quote, not added at the bottom of the invoice.
Other work in Nivelles
While we are on site
Combining two jobs in one visit brings the invoice down. We suggest it when it makes sense, never to pad the quote.
Roof insulation in the neighbouring municipalities
Your job in Nivelles
On-site visit, detailed costing within 48 working hours, with no obligation on your part.
