Green Roof In Bangkok

[Silurian]

Our townhouse in Bangkok has a nice empty flat roof that seems to be perfect for a green space. We are thinking about creating a "Green roof" but not quite sure what materials and plants to use. I have researched the WEB and come up with a few ideas. I also plan to go hunting for a book or two. I was just wondering if anyone had any experience with creating a green space/garden on a flat roof in Thailand specifically Bangkok. I've looked around Bangkok and seen that there are a few buildings that have plants on top of them so I figure it is possible.Most of them look like someone just put out a few pots with plants in them. Maybe it is that easy.

[Farma]

I'd be inclined to do some research on waterproofing your roof area first. Some buildings have a tin roof over the concrete roof. I asked if that was done for shade but told a lot of time its done to stop water leaking through the concrete roof after other methods had failed to stop water leakage.

[PhilHarries]

I'd be inclined to do some research on waterproofing your roof area first. Some buildings have a tin roof over the concrete roof. I asked if that was done for shade but told a lot of time its done to stop water leaking through the concrete roof after other methods had failed to stop water leakage.

The company I worked for in Thailand had exactly the same problem with persistant, and incurable, leaks through the flat roof. The solution was an secondary sloped roof over the entire building.

Personally I'd think plant pots and troughs would be the best solution. If you are thinking of creating a garden by dumping a layer of earth direct on the roof you'd need a fair depth to retain the moisture and that's a lot of dirt to carry up the stairs.

[shochu]

You would need a special membrane used specifically for this - but i do not know if it is available here in LoS. BUT the main concern is during monsoon floods - where the drainage would have to be adequate and the supports strong enough to support the additional weight when the water doesn't drain as quickly. I think this is one of the reason why i haven't seen this being employed in a monsoon region. But i could be wrong.

There are maintenance issues as well. And if I remember correctly it is not cheap, but will pay for itself in the long run.

Google some U.S. Co's as there will be enough info to get you started.

[lopburi3]

Having had this problem over 30 years ago in Laos the covering of the roof with normal boat building fiberglass solved the problem. Believe the standard treatment was tar in those days. There may be better alternatives now but the fiberglass worked fine. They do sell a waterproof cement here that I used to cover some leaking cracks/mostly sand outside wall and have not had a problem since.

[chownah]

Make sure the roof can support the load...a few pots would PROBABLY be ok....there are lightweight potting soil materials that can be used to reduce weight like perlite, vermiculite, expanded polystyrene bead, etc. but do remember as mentioned before that during a heavy rainfall there will be an additional load from the water held in all the containers as well as on the roof itself.

Edited April 20, 2007 by chownah

[PhilHarries]

Make sure the roof can support the load...a few pots would PROBABLY be ok....there are lightweight potting soil materials that can be used to reduce weight like perlite, vermiculite, expanded polystyrene bead, etc. but do remember as mentioned before that during a heavy rainfall there will be an additional load from the water held in all the containers as well as on the roof itself.

Good point, make sure any large pots or containers are located adjacent to or directly over load bearing walls or you are likely to find you've gained a green bedroom.

[quiksilva]

If you ever get the chance check out the Amata Foundation building on Petchburi Road. The roof top is visible from Bangkok Tower and probably Ital Thai.

They have a Thai style house up there surrounded by a lawn, trees, bushes, etc all on the roof of their office building, it really makes for a great environment. Just make sure that the load bearing capacity is sufficient and that the roots are not too destructive!

In fact Amata used to have a lion, a leopard and a tiger roaming around up there (truth!) these days its just a reindeer wanderring around the car park...

[Swelters]

This is an appealing idea with a lot of maintenance issues, not the least of which is keeping everythng well watered, maybe even a couple of times a day in the hot season. If it's cooling you're after you can accomplish the same thng with black or green netting suspended a meter or so aboe the roof -- and then not worry about it for a few years.

Swelters

[JoeInSurin]

I design most of the Garden roofs on commercial structures in the Washington D.C. and metro area from my home in Surin. I can help you with any info. you would need. Depending on what you want to grow there is an "extensive" system for smaller plants with approx. 4 inches of soil and there is an "intensive system" for larger plants with 6 inches + of soil required. The systems usually are made up of a waterproofing membrane on the concrete deck, a root stop material, insulation (if required), a moisture retention mat, a drainage composite, a system filter fabric and then the soil and plants. I am not sure how many of the manufacturers I deal with would have there products available here. Go to www.hydrotechusa.com and check out their info. on the Garden roofs. They have the best system available but there are many others. Any help you need with design just e-mail me.

[Silurian]

Standing water on the roof is a concern. I already had to fix a drainage problem where too much water was pooling in an area. I had to have a small channel cut into the cement for it to drain properly. So far the roof doesn't leak on its own but I was worried that after putting in a green roof things might change. Thanks for the URL, JoeInSurin. It has a lot of good information on the various layers. I will definitely need to do some more research before starting this project. I think the hardest part will be coming up with a design. We already ran water up to the roof so one step is done but there is a long way to go.

As far as why we are planning the garden, I thought there would be several benefits. It would help keep the house cooler, be a nice green place/garden to enjoy, and give the wife unit a hobby. I would think there is some positive environmental impact as well. I will need to keep in mind the extra load on the building. Other units in our community have built structures and put plants on their roofs.