Felt or tiles on extension roof (with photo!)

[Wigeon]

So our tiled kitchen extension roof has leaked ever since it was built a few years ago, and so after several attempts by a roofing specialty mend it, it’s finally being felted in order to seal it completely.

But do we get the tiles put back on, for aesthetic reasons? It’ll be an extra £500 but might be worth it to look nice. OTOH, maybe the felt is fine. DH thinks one thing, I think the other.

The felting in the photo is almost finished but not quite; roof guy coming today to finish it and needs to know if we want the tiles back on or not. You can see the roof from our bedroom, and you can sort of see the side of the roof from the garden deck next to the extension. But you can’t see it much at all from the (small) garden.

WWYD?!

If it's still waterproof, I'd save for the tiles if I didn't have the money. Will the new tiles really stick out with the weathered ones? Can you get the rest of the roof cleaned?

The extension roof isn’t joined up to anything, so it would be a case of putting the tiles which were on the roof back on (you can just see them stacked up on the scaffolding).

The felt will make the extension roof waterproof.

We could afford the £500 but obviously don’t want to spend it if the felt looks fine and so there’s no aesthetic reason to replace the tiles!

Put the tiles back on. They will provide extra protection against the elements. For £500 I think it's worth the money, you already have the tiles anyway.

The roof guy says the felt should last for ages and provide adequate protection...

I'd put the tiles back, if you could afford to. Hope the leaks stop now.

I would say tiles back on; looks nicer, extra protection and you won't have to amend your house insurance from 'all roofs are standard tiling'

Tiles back on, it doesn't look very nice or finished really with the felt on show.

Absolutely tiles back on, otherwise it won't look finished

Ah, I hadn’t thought of the home insurance angle. Hm.

I had been thinking tiles, husband and roof guy reckon the felt is fine. And roof guy thinks with the battens the tiles need to go on, it will raise the level of the roof up quite high around the veluxes (altho not higher than them, which would be weird).

He’s going to mock up a small tiled bit to show me.

Interested in other thoughts altho so far unanimous in favour of tiles!

Fibre glass is usual these days.

Maybe @Pigletjohn can help. He's usually spot on with his advice.

I think the tiles would add an extra layer of protection and look better.

To put tiles back you'll be nailing through the felt, potentially a leak point.

Why was the roof leaking before? Not enough pitch for the tiles?

Felt is a cheap waterproof finish and will not last as long as tiles. About 20 years is life expectancy. If the roof was built with the velux windows then putting back tiles shouldn’t change much. There is a slope on the roof so it should not have leaked. I would suggest it wasn’t properly constructed where it joins the rest of the house and let water track down inside. Therefore the roof finish may not matter if it’s not constructed or joined properly. Did you ever trace the source of the leak or water ingress?

The tiles would look a lot better but you now have two external finishes and you only needed one!

Tiles. Just because it looks unfinished and you have them anyway. We have felt on our garage and it's flat and we have no leaks so I would imagine would be fine without. But definitely for cosmetic reasons. I would also worry about saleability if you didn't put them back on if you wanted to sell on future

@Rollercoaster1920 and @BubblesBuddy - Rollercoaster is right, the roof guy reckons the builder didn’t create a steep enough roof on the extension, and so the rain was getting blown back under the tiles, rather than running off the roof. It mostly doesn't always leak when it rains, but it’s come through the ceiling in two places on several occasions, around the veluxes. It seems absolutely fine where the extension meets the house, no leaks there so I don’t think that’s a problem.

I’d thought about how the battons the tiles will be fixed to being nailed through the felt but the roof guy reckons it will be ok. I also thought that any future buyers might think it looks a bit crap but because the roof guy and DH seemed not fussed I wasn’t sure.

However, the unanimous responses here have emboldened me to convince DH we should go for putting the tiles back and he’s agreed that it would look better that way .

Home ownership is a real privilege, but this kind of thing is a complete pain!

Do you have standard concrete tiles? There are tiles designed for low pitch roofs. I'd be asking who designed the extension whether they specified the right materials.

I'll declare my interest: I'm planning a rear extension and looking at low pitch vs flat roof, so want to know what works and what doesn't!

SSQGroup have a guide to low pitch roofs. They specifically talk about slate but there are other solutions.

I assume they are standard tiles. We didn’t have an architect as it’s a very basic extension (just 3m x 3m, everything very standard). We’d visited /spoken to three former clients of the builder who’d had kitchen extensions and they were all happy, so it’s really annoying that we’ve had this roof issue. Everything else is fine, including the kitchen he fitted in the main bit of the house (the extension just has our dining table in it).

Really hoping this fix will mean we never have to think about it again!

Essentially if you put battens on the roof and then tile it you are treating your top felt as an underfelt. However, underfelt should be a breathable membrane. If you tile over your felt then you will need to vent the roof space. I can't tell if your roof space is vented from photo. If it isn't then you will definitely need to vent it (the felt will prevent air flow which would lead to the joists etc rotting over time).

The pitch of your roof looks to be shallow and might be a problem, depending on what tiles you have. You need to determine what the pitch is. As a PP said this could well be the reason for the leak you had.
I don't know what your tiles are made of. If they are concrete then they maybe okay on a low pitch but if they are slate you need a minimum pitch of 22 degrees while clay requires a minimum of 35 degrees.

Tiles do look better but offer no more protection than felt. However they are more durable.

Also you said the two leaks were around the veluxes which makes me wonder if there wasn't a problem with the roof at all but that the veluxes were not sealed properly.