What is the go-to reference for flat roof coverings in 2023 onwards? EPDM? Liquid coatings? Felt?

Also any brands preferred? I'm looking to put a few of my team on a flat roofing course but as with most things they are 'product specific' to ensure warranties are met.

Would you also try to eliminate flat roofs where possible or do they serve a purpose?

In my case, I used EDPM on a 4m x 10m flat roof over the garage. The advantage in my opinion, is it came as one piece, factory sealed seams so effectively no on-site joins to go wrong. The downside, is as one piece, it was very heavy and floppy to get onto the roof!!!

Also used on my warm roof balconies over which I 'floated' some roof tiles (that is because my roof tiles are from NuLok and are virtually flat on the underside.)

I hate flat roofs?. In all cases in my way of thinking they should not be flat, min fall 1:40 then most coverings work.

If pushed my order of preference would be from top covering downwards, lead, asphalt, high performance felt, then the rest

We have two flat roofs on our house. One area over the front porch, and the roof of the sun room (which gets called the conservatory). Both have Firestone EPDM, installed by the same people who installed our standing seam roof on the house itself. Both appear to be holding up well so far (about 8 years), as is the standing seam. Very professional crew.

I gather Firestone is well-known and one of the better brands.

I don't think there's anything wrong with flat roofs as long as the falls are correct as already mentioned and the drains are thought about. If it was more sunny here, I'd think about putting chippings or paving slabs or somesuch on top of the rubber to keep the sun off; or have engineered the structure so I could put a green roof on top.

I wouldn't want felt or ashphalt etc. And lead is an invitation to thieves around here. As I said, I think the alternatives are GRP or TPO. Each to their own I suppose, and don't buy a house and hope to rely on the NHBC

Parapets would be good but again, what materials would be best suited such purpose?

Thanks

@djh;
Because of a project I'm involved with I'm curious about flat roof parapets.
You mentioned yours are aluminium I'm assuming they are right on the edge with a fascia extending down the wall. If so approx. how much down the wall does it go, I guess it overhangs the wall, by how much, does driving rain drip from it? If this is the case does it affect the wall e.g. staining?

Posted By: owlmanYou mentioned yours are aluminium

No, I said they were timber. With an aluminium flashing cap.

I've never looked to see what happens when there's driving rain. We haven't seen any problems. I assume water falling on the parapet drips or runs off it, apart from what little evaporates. Just as the water falling anywhere else does.

I like sedum flat roofs too. Was just too busy to think about them when building.

I can't find any details at the moment. I'll have a look tomorrow.

OK many thanks Dave;
My situation is also horizontally boarded with an aluminium clad parapet on a flat roof. I was primarily concerned about rain runoff from the fascia bit onto the timber under and below potentially creating problems. I think with a bit of detailing like sloping the aluminium top, inwards onto the flat roof, and keeping the exterior down stand e.g. 150-200 max. don't know yet about any exterior drip detail on the aluminium bottom edge, I'm guessing just a upturn towards the wall. Have to see how the aesthetic looks.

Posted By: borpinThe other thing to consider is ventilation; is the gap between the timber cladding and the fascia down stand bit needed for that. If not, have a small under turn on it and when fitting put some expanding EDPM foam tape between it and the timber.

I'm not sure I understand. What gap? The aluminium flashing is formed down over the timber cladding, so there's no ventilation gap as such although I expect liquid water could run down if it needed to. And what benefit would be gained by sealing that space anyway?

In general I tend to favour keeping things open where possible to allow as much ventilation and thereby evaporation as possible. I'd think that if there was enough wind to drive rain up behind the flashing, it was likely to be enough to bend the flashing outwards as well. The area behind the flashing is pretty much sealed apart from at the bottom (including the area behind the cladding as well. So I'd expect the wind to build up the pressure there so that the wind didn't actually blow into that area. So not much rain carried up either.

Certainly I can't see any great difference between the cladding up top and that lower down. But then we don't live in an area of extreme weather, so things might differ depending on where a building is.