What it costs to replace a flat roof depends mainly on the surface area, the chosen material (bitumen, EPDM or PVC), insulation, drainage slope, skylights, edge finishing and accessibility. Sometimes an overlay is a cheaper alternative. A free roof inspection and quote give you real certainty.
When does a flat roof need replacing?
A flat roof does not last forever. Once the roofing blisters, cracks, shrinks or leaks in several places, repairs are often no longer enough. The same goes for a substrate saturated with moisture or damaged insulation — replacing pays off more than patching it again and again. Not sure? A roof inspection is the best first step: we assess the condition of the roofing, the insulation layer and the edge finishing, and tell you honestly whether replacement is genuinely needed.
A good rule of thumb: if more than a third of the roof is worn out, or if the covering has reached the end of its lifespan, full replacement is usually wiser than continuing to repair.
Bitumen, EPDM or PVC: which material should you choose?
Three materials are commonly used for flat roofs. We have traditionally specialised in bitumen, but we also install EPDM. Below we compare their properties so you can make an informed choice — not on price, but on what suits your roof.
| Property | Bitumen | EPDM | PVC |
|---|---|---|---|
| Lifespan | 30+ years (torched, double-layer) | 40-50 years | 25-35 years |
| Number of seams | Many, but fully fused | Few (often one piece) | Welded seams |
| Maintenance | Low | Very low | Low |
| Resistance to roots/UV | Good (mineral top layer) | Excellent | Good |
| Suited to irregular shapes | Excellent | Less so (large areas) | Good |
| Walkability / roof terrace | Good | Good with protection | Good |
When bitumen? For roofs with many corners, dormers, penetrations or skylights. Torched bitumen seals perfectly around detailed work and is exceptionally durable. Read more about the differences in our article on bitumen, EPDM or PVC.
When EPDM? For large, rectangular areas where a single, tight rubber membrane with few seams is the ideal, virtually maintenance-free solution.
When PVC? For specific industrial applications or where welded plastic is preferred. In practice we usually recommend bitumen or EPDM for their proven durability and straightforward repairability.
What determines the cost of replacing a flat roof?
We deliberately do not publish fixed prices, because no two roofs are the same. What does determine the cost is easy to explain:
- Surface area — how many square metres of roof are being replaced.
- Material choice — bitumen, EPDM and PVC differ in material and installation effort.
- Insulation — is the insulation layer being renewed or upgraded (for example to meet modern standards)?
- Drainage slope — does a new slope layer need to be created so rainwater drains properly?
- Removing the old covering — stripping and disposal take labour and time.
- Skylights, dormers and penetrations — every detail requires extra connecting work.
- Edge finishing — roof trims, upstands and gutters shape the finish.
- Accessibility — is scaffolding, a crane or an aerial platform needed, and how far do we travel?
On our recent project in Pijnacker we replaced 615 m² of flat-roof covering with a double-layer mineralised bitumen system — a good example of how surface area, material and detailing together shape the work. You’ll find more examples among our projects.
Does it always need replacing? Consider an overlay
Not every worn bitumen roof needs to be stripped completely. If the substrate is still dry and sound, an overlay is often the smarter alternative: we torch a new bitumen layer over the existing covering. That is faster, produces less waste, improves insulation and makes your roof fully watertight again — without the cost of a full tear-off. Read how it works in bitumen roof overlay. Whether an overlay is possible is something we assess during the inspection; with a saturated or damaged substrate, replacement remains the right choice.
Want to know all your options? On our page about flat roofs you’ll find what we can do for you.
Honest advice and a free quote
The only honest way to know what your flat roof will cost is for us to see it first. At Dakservice van Belzen — the family business of brothers Tonnie, Jos and Noah — you are never just a number. We come by for a free, no-obligation inspection and quote, clearly explain your material options, and give up to 15 years of warranty on the work. We respond within 2 hours via WhatsApp and are often on site within 24 hours. Get in touch and you’ll quickly know where you stand.
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Frequently asked questions
Often, yes. If the existing substrate is still dry and sound, we can torch a new bitumen layer over the old one. That is faster, produces less waste, improves insulation and makes your roof watertight again. If the substrate is saturated or damaged, full replacement is the right choice. We assess this during the inspection.
EPDM has the longest average lifespan at 40-50 years and is virtually maintenance-free. A torched, double-layer bitumen roof typically lasts 30 years or more and is excellent for roofs with many corners and details. The best choice depends on the shape and use of your roof.
Because no two roofs are the same. The cost depends on surface area, material, insulation, slope, skylights, edge finishing and accessibility. Only once we have seen your roof can we give you an honest price. That's why a free roof inspection and no-obligation quote are the only proper way.
We usually respond within 2 hours via WhatsApp and are often on site within 24 hours. After the inspection you receive a clear, no-obligation quote with an explanation of the material options and up to 15 years of warranty on the work.