EPDM Rubber Roofing › Cardiff › Guide
Many flat roofs on Cardiff terraces and semis are still covered in felt, and many owners are asking whether EPDM is worth the switch. The two coverings are made differently, laid differently and fail differently. Here is a straight comparison, without selling you either one for roofs that do not suit it.
How each covering is made
Felt roofing is built up in layers of bitumen-based sheet, joined at the overlaps and often finished with a mineral cap. EPDM is a single sheet of synthetic rubber. One has many joints and layers, the other has as few as the roof size allows. That is the starting point for almost every difference between them, from how the roof moves in heat and frost to how it is repaired later.
How each is laid
Felt is usually torched or bonded in overlapping strips, so a roof has many seams that have to be sealed. EPDM is rolled out over a prepared deck, bonded with adhesive and trimmed at the edges. On a small garage or porch roof in Cardiff it can often go down in one sheet with no seam in the main field.
- Felt uses overlaps and seams across the roof.
- EPDM is bonded with adhesive in a single sheet.
- Both need a sound, dry and well-fallen deck.
- Edge trims and upstands apply to both.
Where each one tends to fail
Felt usually fails at the seams, edges and laps, and cracks as it ages and moves. EPDM fails where the detail is poor, such as a badly formed corner or a lifted edge. In both cases the deck and the drainage decide how long the roof performs. A well-laid felt roof can outlast a badly laid EPDM one.
Which suits which Cardiff roofs
For garages, rear extensions, porches and dormer flats, EPDM is often a better fit because of its few joints and neat upstands. A felt roof can still make sense on a simple, accessible roof or where the budget is tight. We look at the shape, the size and the junctions before recommending either, and we tell you if we think your existing covering still has life in it.
Questions to ask before you choose
Ask what the deck is like, how the edges and upstands will be formed, and what happens at the wall junction. Ask what the insulation is and where the water goes. A fair answer talks about the whole roof, not only the top sheet. Our Flat Roofing South Wales section sets out the options in more detail.
- What is the deck made of and what shape is it in?
- How will edges, corners and upstands be finished?
- Where does the water drain to?
- What is being done about insulation?
Need epdm rubber roofing in Cardiff? See our epdm rubber roofing in Cardiff page, or call 07766 547309.
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Common Questions
Is EPDM better than felt?
For many small and medium flat roofs, yes, mainly because of the fewer joints. But a sound felt roof is not worth stripping for the sake of it. We look at the roof and give you a straight answer.
Can a leaking felt roof be repaired instead of replaced?
Sometimes, if the leak comes from a local split or a lifted edge and the deck is sound. If the felt has cracked widely or the deck is wet, repairs only buy a little time, and we say so.
Does EPDM suit a Cardiff extension with a complicated shape?
It often does, because it can be formed around corners and upstands. A very awkward shape needs more detailing, which we plan beforehand. We look at the roof and talk through the junctions before suggesting the method.
Get a Quote in Cardiff
Tell us what the roof is doing in Cardiff and we will look at it. Call 07766 547309, message us on WhatsApp or use the form below.