
Roof insulation
in Sint-Pieters-Leeuw
On the edge of the Pajottenland, Sint-Pieters-Leeuw brings together village centres, large residential zones and open farmland. Roof insulation of the loft, the loft floor and the roof slopes, with a continuous vapour barrier and ventilation kept clear.

The context in Sint-Pieters-Leeuw
Why here in particular
What changes in Sint-Pieters-Leeuw is the context: brick terraced houses, Pajottenland farms, estates from the 1980s. Open exposure to the west wind wears the verges and regularly tears off badly bedded ridge tiles.
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 Sint-Pieters-Leeuw 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 Sint-Pieters-Leeuw
The questions we get asked most often before this kind of job.
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 lose ceiling height?
On a pitched slope yes, a few centimetres. We measure it beforehand so you can decide knowing the facts.
What thickness should you aim for?
For a roof slope, 22 to 30 cm in total depending on the product’s lambda. Below that, the gain does not pay for itself.
Do you come out to Sint-Pieters-Leeuw with no extra call-out charge?
Yes. Sint-Pieters-Leeuw 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 Sint-Pieters-Leeuw
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
All our work in Sint-Pieters-Leeuw · Everything about roof insulation
Roof insulation in Sint-Pieters-Leeuw: let’s talk about it
On-site visit, detailed costing within 48 working hours, with no obligation on your part.
