Onduline FAQs

1. How long is Onduline guaranteed for?

Onduline roofing sheets are guaranteed to remain weatherproof for fifteen years under normal usage, when fixed and maintained in strict accordance with the fixing instructions. The guarantee is non transferable and does not cover the aesthetic quality of the material. The guarantee after five years service is limited to the pro-rata replacement value of the Onduline materials set against the service life measured in annual increments and does not extend to labour, related construction or third party costs.

2. Which way up is an Onduline sheet fixed?

Onduline roofing sheets are easily identifiable by the printed production quality control information applied up the last corrugation on the smooth grained topside (photograph on right).

3. Do you sell clear PVC sheets to match Onduline profile?

Yes, PVC Onduline Profile Sheets are available in two forms - 'glass clear' transparent to provide optimum clarity and light transmission and translucent for use where diffused lighting is required. Manufactured to the same size and profile as Onduline corrugated sheets, they provide a simple, economical way of gaining light through the roof. Material Specification: Length: 2000mm Width: 950mm


4. Is Onduline fireproof?

Onduline sheets are not classified to External S.AA fire rating as required in UK Building Regulations for some classes of structure. In these cases they must be fixed on a suitable fully supporting roof deck and the sheets coated with a proprietary AA surface paint treatment as used on flat felted roofs applied in accordance with the paint manufacturer’s instructions.


5. How can I find my local supplier?

Click here to locate your nearest stockist. https://onduline.co.uk/stockists/ 

If you are unable to find a suitable outlet please contact our sales office on 0207 727 0533.


6. What is the overhang needed for Onduline sheets? 

The maximum overhang of Onduline sheets at the eaves is 70mm.


7. What is the minimum pitch for Onduline sheets? 

The minimum roof pitch to lay Onduline roofing sheets is 5 degrees / Gradient: 1 in 11 the sheets being laid with an End Lap of 300mm. Sheets laid on a fully supporting decking on purlins to maximum of 610mm centres. Sheet Side Lap: 2 Corrugations. Fixings: 20 per sheet. Consult the Onduline Fixing Guide for full instructions.


8. Do you supply Onduline in different lengths?

No, Onduline comes in one standard size of 2m x 0.95m; please try our Onduvilla for smaller sheet sizes.


9. How many nails should I user per Onduline sheet?

20 - 25 nails dependant on the roof pitch. Consult the Onduline Fixing Guide for full instructions.


10. How can I cut an Onduline sheet?

Cut with an oiled coarse-toothed handsaw or preferably a power tool; such as a circular saw again fitted with a course blade or skill saw. Consult the Onduline Fixing Guide for full instructions.


11. What is the difference between Onduline and Coroline?

Onduline is regarded as the professional sheet and the Coroline material is normally associated with DIY applications. For example; Onduline sheet is the only corrugated bituminous sheet suitable for use as a base sheet for the patented Ondutile tile underlay system. Onduline being nominally 3mm thick, compared to the 2.6mm lighter quality Coroline DIY sheet.


12. Can Onduline be used as Wall Cladding? 

Yes, Onduline can be used as wall cladding where it will need to be secured to horizontal battening fixed at 600mm centres. I would however recommend that you consult any local building regulations or planning permissions that may apply to the proposed building, prior to the commencement of any work.


13. What is the difference between Onduline and Ondutile?

Ondutile is a unique roof underlay system utilising Onduline PP corrugated roof sheets below tile, slate or shingle roof coverings to create an independent secondary weatherproof roof. This enables the primary tiled roof to be used safely below the manufacturer’s minimum roof pitch.

14. Is it possible to paint Onduline sheets?

We do not particularly recommend any particular product or manufacturer. However the easiest material to use is external grade water based emulsion such as a Masonry Paint. One could also use a bituminous paint which in practice is harder to apply and maybe restrictive as to available colours. In any event and prior to commencing work, it is essential to totally remove any loose dust and debris from the sheeting. At the same time, it would also be advisable to test a small area to determine if there are any compatibility issues. This information is provided in good faith and there are no guarantees; the durability of the system will largely depend on the materials involved and the preparation beforehand.


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