Short Answer
C250 is generally specified for commercial car parks, kerbside drainage and medium commercial environments where cars and light vans are the primary vehicle type.
D400 is required for roads, highway drainage and areas subject to regular heavy vehicle traffic — including HGV delivery routes, industrial roads and access roads carrying loaded heavy goods vehicles.
Comparison Table
| Criteria | C250 | D400 |
|---|---|---|
| EN 1433 classification | C250 | D400 |
| Typical application | Commercial car parks, kerbsides | Roads, HGV routes, industrial roads |
| Primary traffic type | Cars, light vans, occasional light commercial | HGVs, heavy commercial vehicles, road traffic |
| Channel material (typical) | Polymer concrete | Polymer concrete |
| Grate material (typical) | Ductile iron, composite | Ductile iron, RapidLock ductile iron |
| Forti Nova products | Domo C250, Hydro C250, Hydro Plus C250, U100 C250 | R100, R150, R200 RapidLock; U100 |
When C250 is Appropriate
C250 is suitable for commercial car parks where private cars and light vans are the main vehicle type. It is also used for kerbside drainage in pedestrianised areas and some commercial yard applications where vehicle weights are moderate.
C250 should not be assumed suitable where HGV access is regular or where the channel sits in a road carriageway. If delivery lorries regularly cross the drainage channel, the D400 classification should be assessed.
When D400 is Required
D400 is the standard classification for road drainage and heavy vehicle areas under EN 1433. It is required for roads, highway drainage, industrial roads and access roads regularly used by HGVs. If a project involves road adoption or highway authority requirements, D400 is typically the minimum classification.
For extreme industrial environments — aircraft stands, port facilities, dock drainage — F900 may be required rather than D400.
Frequently Asked Questions
Is C250 sufficient for a commercial car park?
C250 is commonly specified for commercial car parks used by standard cars and light vans. Where HGV delivery vehicles regularly access the car park and cross the channel, D400 should be considered. Confirm the vehicle type and crossing frequency with our team.
Can I use C250 on a road?
No. Road drainage and areas subject to regular heavy vehicle traffic should be specified at D400 as a minimum. C250 is not rated for standard road applications. Using an under-rated channel in a road application is a structural risk.
What is the difference between C250 and D400 in practice?
C250 is tested under a different load condition than D400 under EN 1433. D400 is required for roads and areas where heavy vehicles routinely cross the channel. The practical difference is in the type of traffic, frequency of crossing and the structural demands placed on the channel and its installation.
Which products does Forti Nova supply at C250 and D400?
Forti Nova supplies Domo C250, Hydro C250, Hydro Plus C250 and U100 C250 at C250 classification. At D400, we supply R100, R150 and R200 RapidLock channels and U100. Contact us for project-specific guidance.