revtothelimit - motorbike forum

mangocrazy wrote: Sun Sep 15, 2024 1:41 pm

Count Steer wrote: Sun Sep 15, 2024 11:48 am flat roof with drains in the middle ie no gutters and lots of trees around.

What could possibly go wrong?


More to the point, what did actually go wrong...?

Same as the (concealed) drains on my neighbours green roofs.

I don't 'get' flat roofs. Never have, never will.

mangocrazy wrote: Sun Sep 15, 2024 1:41 pm

Count Steer wrote: Sun Sep 15, 2024 11:48 am flat roof with drains in the middle ie no gutters and lots of trees around.

What could possibly go wrong?


More to the point, what did actually go wrong...?

Well, the 'flat' roof actually sloped inwards to the two drains (which ran into pipes enclosed in brick inside the house then out under the house to a soakaway somewhere I assume, or possibly into the drains - I think that was allowed at the time). The wire mesh over the top would clog with leaves so I'd be up there in the rain clearing the impromptu pond on the roof. The roof itself was simply boarded and 3 layers of tarred felt on it. The water itself wasn't the big issue, it was more the sun on such a large expanse. The previous owner had painted it with some silvery, reflective sort of rubberised stuff.

Eventually water would get through and, underneath between the roof and the suspended, acoustic tile ceiling was several inches of loft insulation. You know what happens to acoustic tiles when they get rather wet and a little weight is applied?

I had the roof re-felted and decided to just replace the necessary acoustic tiles, which were Imperial size. Of course, the only ones available were metric which meant the support grid had to be rejigged and I redid the ceilings throughout the house.

Some time later....it leaked again. So, employed an architect, designed 2 × 5 bed houses for the plot. Spent several years playing Catch 22 with the planning system, neighbours - next door on one side mainly - etc but won eventually. Sold to another neighbour who ran a 'boutique' development company and he built the 2 houses. V nice they were too, local vernacular all that jazz (half tiled etc). Sold in a jiffy for many quids.

We had to get out reasonably pronto as they wanted to get on with demolition, bought this place, temporary like. Still here nearly 15 years later.

Oh yeah, this roof leaks a tiny bit but only when the rain is driving in horizontally from a v specific direction. Arf!

Oh. As this is the pix thread. I think these are council houses at Chalk Farm, Lunnon. Used to live not far away.

mangocrazy wrote: Sun Sep 15, 2024 1:38 pm

Mr. Dazzle wrote: Sun Sep 15, 2024 11:15 am

mangocrazy wrote: Sun Sep 15, 2024 10:29 am Fair bit of cantilevering going on there. I'm sure all the design calcs have been done and the concrete sections are heavily Rebarred, but it doesn't quite look right to me from an engineering standpoint.

The concrete sections are "off the shelf" built for the express purpose of being beams and cantilevers in motorway bridges. That house is pretty much a holiday for them

I'm sure you're right, but it just doesn't look quite right to my untrained eye.

That's half the fun

99% of buildings here have flat roofs.

Mr. Dazzle wrote: Sun Sep 15, 2024 2:26 pm

mangocrazy wrote: Sun Sep 15, 2024 1:38 pm

Mr. Dazzle wrote: Sun Sep 15, 2024 11:15 am

The concrete sections are "off the shelf" built for the express purpose of being beams and cantilevers in motorway bridges. That house is pretty much a holiday for them

I'm sure you're right, but it just doesn't look quite right to my untrained eye.

That's half the fun

Cantilever that don't look 'right'? Laydeez n' Gemmun I give you the 'Just Because You Can Doesn't Mean You Should, Pig's Ear' award winner.

But if you must, then get it (Loyd W)right -

'Fallingwater'

Yorick wrote: Sun Sep 15, 2024 2:53 pm 99% of buildings here have flat roofs.

They are certainly the easiest style of roof to build. But what is your annual rainfall? And don't I recall you having to re-do your flat roof a while back?

mangocrazy wrote: Sun Sep 15, 2024 4:18 pm

Yorick wrote: Sun Sep 15, 2024 2:53 pm 99% of buildings here have flat roofs.

They are certainly the easiest style of roof to build. But what is your annual rainfall? And don't I recall you having to re-do your flat roof a while back?

Flat roofs in the UK are a nightmare. I suppose designs evolve based on what works locally and available materials. The UK's not much good for making adobe bricks but we had plenty of fuel for brick and tile works. Some areas had plenty of thatching material too*.

Concrete's available pretty widely but there have been a few problems with it in wet places if it has metal reinforcement. Romans did OK with their cement/concrete without the metal though

Traditional Japanese houses were designed to not make too much of a thump in an earthquake I believe, but we don't get too many of them.

Different strokes for different folks/places.

*Wonder how many countries have/had thatched roof houses??

Yorick wrote: Sun Sep 15, 2024 2:53 pm 99% of buildings here have flat roofs.

Surrounded by lots of trees and in an area of high anual rainfall, especially if it's got an internal gutter means it gets blocked by leaves and then deposits its contents into the internal building envelope (on yer telly) which is an utterly dogshit idea.
Normal gutters (even on a flat roof) just leak on the outside of the building and cause a damp patch at the top of a wall. Thats less of a dogshit idea.

I'm gonna guess that you don't have over a metre of rainfall per year, nor several sycamore tree's overhanging the house.
Plus a lot of homes in Spain use the flat roof as a roof terrace so in theory, its better maintained and if there's a blockage its easy to access.

Before the last building work,we had a room with a flat roof for over 30 years with no bother. Materials have improved since then.

It rains the odd time here.....

The roof on my house is flat.

It's just tilted at an angle too.

Some years ago I was in Cyprus, where flat roofs are also prevalent (as is minimal rainfall) and they used the flat roof as a place to mount solar thermal tubes and an insulated hot water tank. Most houses had such an arrangement as I recall.

Mr. Dazzle wrote: Sun Sep 15, 2024 5:40 pm The roof on my house is flat.

It's just tilted at an angle too.

The roof on my French house is wavy. And it's at an angle (about 20-25 degrees).

demographic wrote: Sun Sep 15, 2024 5:37 pm

Yorick wrote: Sun Sep 15, 2024 2:53 pm 99% of buildings here have flat roofs.

Surrounded by lots of trees and in an area of high anual rainfall, especially if it's got an internal gutter means it gets blocked by leaves and then deposits its contents into the internal building envelope (on yer telly) which is an utterly dogshit idea.
Normal gutters (even on a flat roof) just leak on the outside of the building and cause a damp patch at the top of a wall. Thats less of a dogshit idea.

I'm gonna guess that you don't have over a metre of rainfall per year, nor several sycamore tree's overhanging the house.
Plus a lot of homes in Spain use the flat roof as a roof terrace so in theory, its better maintained and if there's a blockage its easy to access.

Bugger all rain and the roof is solid concrete.

Skub wrote: Sun Sep 15, 2024 5:39 pm Before the last building work,we had a room with a flat roof for over 30 years with no bother. Materials have improved since then.

It rains the odd time here.....

Parapet walls round it, nternal gutters with loads of overhanging trees?
I'm guessing not.

To be fair, I'm more against internal gutters than a flat roof and there's a lot of pitched roofs with internal gutters (often on old hotels with several extensions) as well.
Oh and as Dazzle has pointed out, they're not actially flat and generally have about 20mm or so fall per metre.

mangocrazy wrote: Sun Sep 15, 2024 10:29 am

Mr. Dazzle wrote: Sun Sep 15, 2024 7:58 am

mangocrazy wrote: Sat Sep 14, 2024 9:29 pm That will take a fair few Readymix lorries to fill. Presumably there is a standard template for structures of this sort and all the shuttering gets re-used multiple times?

Goes beyond even that, there are standard beams, columns etc. that are pre made off site.

There's a house in Spain made from them. I think it's great but it may not be to all tastes.

Yes that is a swimming pool in that huge gutter.

Fair bit of cantilevering going on there. I'm sure all the design calcs have been done and the concrete sections are heavily Rebarred, but it doesn't quite look right to me from an engineering standpoint.

And with my aesthetics hat on it's just plain f'n ugly... The Park Hill flats in Sheffield (which I can see from where I'm typing this and were inspired by Corbusier's work) are downright pretty compared to that.

That house featured on George Smiths Amazing Spaces.

This one makes me think of 'Hang on lads, I've had an idea!'



PS it looks like a stretch-limo version of a corporation toilet.

I bet the neighbours were pleased.

Bloke over road from our restaurant having a barbie in the street