Thread: Green Roofs?

Green roofs weigh a ton so they need a lot of support. It's of course possible to do this with materials other than concrete but the ones I've seen/read about have been concrete-based. Also, as others have said, it's dry here a lot of the time. Where I live, it doesn't really rain at all for half the year. Having a green roof in that climate just doesn't seem sensible; you've possibly solved a problem by having a green roof but you've also created a new one. That being said, I read a while back that green roofs are being introduced in Mexico City. That seems sensible. If you have a pre-existing building with a flat roof - especially in cities - that can take the weight, shoving a load of plants/turf on it is a good idea - for lots of reasons - but if you're building a new house, I'm just not convinced that, in Thailand, it's the right approach. I've never used thatch here but others who have tell me that it lasts around 3 years, maybe more if you have it at a steep angle. I'm vacillating wildly between thatch and non-thatch on the place I'm going to do - I've started learning toward thatch because of its extreme renewability. The main problem I have with it is that I want to collect my rainwater and that may not work too well with thatch.

Originally Posted by Takeovers

Originally Posted by Dan

Originally Posted by Smithson

they still use a lot of un-sustainable and polluting materials.

I agree. For somewhere like Thailand, it just doesn't seem like an appropriate technology. I really can't see how it can be preferable to a thatched roof, or even a regular, light-weight metal structure.

Which unsustainable and/or polluting materials? Do you mean the pondliner or similar material for watertight sealing?

I would be interested in the lifespan of a thatched roof in a tropical climate. But in the Philippines they are prohibited for fire hazard now anyway.

Unsustainable refers to something that cannot be reproduced within it's lifespan, for example thatch may only last 3-5 years, but during that time it can be regrown, so therefore thatch is sustainable. Plastics, metals and concrete aren't sustainable.

Regarding the thatch being banned in the Philippines, not sure how successful it will be, the 'Nipa' hut with it's thatch roof is a national symbol.

Originally Posted by Smithson

Regarding the thatch being banned in the Philippines, not sure how successful it will be, the 'Nipa' hut with it's thatch roof is a national symbol.

I know the Nipa-Huts and like them.

Nipa are the palm leaf roofs which were very common. I remember well passing by a plantation for the leaves and seeing heaps of woven mats ready for roofs by the wayside. Thatched roofs are a completely different matter, affordable only for few. When you see them it's mainly on Tourist locations.

But in built up areas you can no longer use them or Nipa. Only out in the fields for single buildings and maybe in remote areas.

Originally Posted by Smithson

Plastics, metals and concrete aren't sustainable.

That's an idealized view. I am sure plastics, metals and concrete are sustainable. We willl need them in the future and will probably use organics as an raw material.

By the way thatched roofs are still much in use in northern germany and are expected to last about 20 to 30 years. However with warm winters in the recent past many have been affected by a new strand of moulds and last only 10 years. Research is on the way how to fight those moulds. Those roofs are very thick and labour intensive, so they are way too expensive to replace them that often.

Originally Posted by Takeovers

That's an idealized view. I am sure plastics, metals and concrete are sustainable. We willl need them in the future and will probably use organics as an raw material.

It's not just the materials (though that's important). It's the energy input, too. All of those materials carry vast amounts of embodied energy, which contributes just as much toward their unsustainability.

[QUOTE]

Originally Posted by Takeovers

Originally Posted by Smithson

Regarding the thatch being banned in the Philippines, not sure how successful it will be, the 'Nipa' hut with it's thatch roof is a national symbol.

I know the Nipa-Huts and like them.

Nipa are the palm leaf roofs which were very common. I remember well passing by a plantation for the leaves and seeing heaps of woven mats ready for roofs by the wayside. Thatched roofs are a completely different matter, affordable only for few. When you see them it's mainly on Tourist locations.

That's interesting. Is the Nipa more fire resistant? They have something similar here, it's a thatch with wide leaves that last longer than the other stuff. Have you seen it?

Originally Posted by Smithson

Plastics, metals and concrete aren't sustainable.

That's an idealized view. I am sure plastics, metals and concrete are sustainable. We willl need them in the future and will probably use organics as an raw material.

It depends on what you believe. Some ppl think the future will be hydrogen cars and solar electricity etc. IMO the resources aren't available for this and we will go back to things like pushbikes and growing more of our own food. In Thailand there will be more mud, bamboo and thatch building. The traditional Thai house design is suited to the climate, so building will start to reflect this, although there will be some improvements.

I'm not a hippy or an idealist, I just think the 'brave new world' of green technology is wishful thinking.

Getting back to the green roof idea. Have you been able to find any designs or exisiting building suitable for tropical climates?

Originally Posted by Smithson

I'm not a hippy or an idealist, I just think the 'brave new world' of green technology is wishful thinking.

I am a little more optimistic on that. Not in the short run that's why i oppose sinking multi-billion investments in it right now but I hope and believe we will get there within 50 years from now and hope I can see it starting.

I am also afraid you might be right. That would mean reducing the population to less than 3 billion people because the present population would not be sustainable with those methods. Not a pretty scenario.

^ It's a bit like a car that's heading for a cliff with noone in control. We need to slow down and change direction, but instead we're speeding up - the world population is growing and everyone wants more of everything.

Getting back to the roofs, they may work in Germany, but thatch might be better because it's very insulating doesn't require the huge structure.

In a tropical climate insulation is most needed when air con is used. The problem with insulation here is it will hold heat from the day. At night the temp can drop to around 25, if you place is designed right you can benefit from this and get by without air con. This is why throughout southeast asia they build houses above the ground with lots of windows. The only insulation needed is on the roof, which is why thatch works well.

If you want to build an 'eco' house in Thailand best thing is to look at traditional designs and see how they can be improved.

Originally Posted by Dan

The main problem I have with it is that I want to collect my rainwater

slightly off topic - but it was mentioned to me by a Thai the other week that to collect water off a tiled roof it is advisable to wait about 2 years before it is potable ? has anyone else heard reference to this ?

Hello everybody
some people like to see mor pictures of green roof?
on my online album you can find more
sorry,i dont know the way for put the picture in here
maybe someone can do this
sorry about my bad english,is not my leangues
if you want,follow this link pixum.de/album/4249525/
Greetz Roelfle from germany

Hi Roelfle. I'd be interested in seeing them but the link doesn't work.

Originally Posted by Dan

Hi Roelfle. I'd be interested in seeing them but the link doesn't work.

For me the link worked but you have to log in to see the album.

Hi Roelfle you need to have 10 posts, then you can post pictures.

How to post pictures

We make a lot of green roofs in Australia, but we call them Colorbond.

if you used the www in front of my link,you can see the album .pixum.de/album/4249525/

It requires a username and password.

Originally Posted by baldrick

Originally Posted by Dan

The main problem I have with it is that I want to collect my rainwater

slightly off topic - but it was mentioned to me by a Thai the other week that to collect water off a tiled roof it is advisable to wait about 2 years before it is potable ? has anyone else heard reference to this ?

Never heard it, actually I thought it was the opposite. Best bet is to have a good filter anyway.

Back to the green roofs, I think they could work well here in city areas. Existing townhouses and apartments with flat roofs are ideal. They could be used for growing food either with hydro or straw bales.

There are a few in Singapore, here's a pic:

Saw a show on Discovery the other day. There are some people working on aeroponics in Singapore and they want to start growing fresh produce on all the roof tops in Singapore.

Basically with aeroponics the plant is supported and the roots hang above a trough. A fine aerated nutrient mist is periodically sprayed onto the roots and the excess is caught in the troughs and returned to a resivoir tank to be recirculated.

Upside is that because there in no soil (traditional farming) or troughs foll of nutrient (hydroponics) the weight is kept right down allowing for the use of roof tops.

Downside is that the nutrients and plants require chilling due to the climate which cost a lot in electricity.

Link if anyone interested

Aero-Green Aeroponics