Green roofs ?

stumuz · Post by **stumuz** » 04 May 2008, 14:42

Does anyone know about these
http://www.sustainablebuild.co.uk/RoofPlants.html

I am considering one for the renewal of the piece of flat roof attached to my home.

Are they better suited to drier parts of the country, rather than rainy Wales?

RenewableCandy · Post by **RenewableCandy** » 04 May 2008, 15:12

Sorry can't get the page to display on my antedeluvian bruiser. But if it's talking about Sedum roofs, I do happen to know there's one thriving and surviving on top of the Eco-Cabins at the CAT in Wales (have stayed under it on numerous occasions). Yes even though Sedum is a dry-weather thingie. The extra wind you get on a roof, and the lack of real soil depth, probably keeps it drier than it otherwise would be.

skeptik · Post by **skeptik** » 04 May 2008, 16:17

stumuz wrote:
Are they better suited to drier parts of the country, rather than rainy Wales?

Even so called 'flat' roofs have a shallow pitch to promote drainage. I would have thought green roofs would do better in rainy Wales than in drier parts of the country.

stumuz · Post by **stumuz** » 04 May 2008, 16:50

RenewableCandy wrote:Sorry can't get the page to display on my antedeluvian bruiser. But if it's talking about Sedum roofs, I do happen to know there's one thriving and surviving on top of the Eco-Cabins at the CAT in Wales (have stayed under it on numerous occasions). Yes even though Sedum is a dry-weather thingie. The extra wind you get on a roof, and the lack of real soil depth, probably keeps it drier than it otherwise would be.

Thanks for that, it seems counter intuitive to have a cold wet sod on the roof (except for me!)

Do you know if CAT has any info on this as I?ve had a look at their website and cannot find anything? If CAT does use and recommend them then that is defiantly a seal of approval. When I built the hot water solar panels from the CAT handbook, I was quite sceptical about whether they would work. I now know I will never live in a house again that does not have them!

stumuz · Post by **stumuz** » 04 May 2008, 16:54

skeptik wrote:
stumuz wrote:
Are they better suited to drier parts of the country, rather than rainy Wales?
Even so called 'flat' roofs have a shallow pitch to promote drainage. I would have thought green roofs would do better in rainy Wales than in drier parts of the country.

Strange, it goes against everything that as a DIY builder, I have done in the past. Water is something to be got rid of as soon as possible, and get it away from the house as quick as possible. Radical!

RenewableCandy · Post by **RenewableCandy** » 04 May 2008, 17:00

Can't find it either (after very cursory search) but I know CAT do those fact-sheets and I suppose you could ring them up and ask if they have one about building your own green roof.

There are also loads of firms who do this professionally, lay down insulation, then waterproof membrane, then 'growning medium' (not actually soil) then seeds. Might be a good move unless you're absolutely certain you'll get it right first time, or you might end up being a cold wet sod under your roof...

skeptik · Post by **skeptik** » 04 May 2008, 20:12

RenewableCandy wrote: or you might end up being a cold wet sod under your roof...

er..yes. Cold wet sod is, as I'm sure you appreciate, bloody heavy. Strength of the supporting stucture has to be the first consideration before going any further.

Kentucky Fried Panda · Post by **Kentucky Fried Panda** » 04 May 2008, 21:15

The Oldham public library has a green roof, the rain water is collected, UV treated and then plumbed to the public toilets for flushing use.
I don't have anymore details because I don't work for the construction industry at the moment.

enso · Post by **enso** » 04 May 2008, 21:42

The Construction Industry Research and Information Association (CIRIA) consider sustainable drainage techniques, including green roofs, very favourably. They've got a couple of pages of info on green roofs if anyone is interested:

http://www.ciria.org/buildinggreener/gr ... uction.htm

Also, more info at http://www.livingroofs.org/

Erik · Post by **Erik** » 04 May 2008, 23:21

Don't forget to check out the Reading International Solidarity Centre Roof Garden too! Lots of info + videos at the website.

Post by **kenneal - lagger** » 05 May 2008, 02:06

Green roofs work well and temper the temperature of the room below. They also make any felt covering last a lot longer than it would if exposed to UV, and general sun, light. flat roof coverings are attacked by both UV and carbonic acid in evaporating rainwater. The green roof covering stops both these attacks.

Whatever roof you plant, allow it to evolve naturally and you will have the most sustainable roof for your climate. I went to see a building with a sedum roof recently and the building manager had been told to weed it to keep it 100% sedum. what waste of time! If a plant can grow on a roof and carry on growing there it must be suited to that location. If it grows there but doesn't survive, why bother to weed it out.

Just make sure that the roof structure is suitable to take the additional weight.

Tangata · Post by **Tangata** » 16 May 2008, 14:07

I've got two green roofs -

I ordered sedum plug plants from Blackdown Horticultural http://domain879190.sites.fasthosts.com/

Planted them in about 75mm of compost / course grit mix. One roof is normal felt covered with old carpet and a sheet of dpm, the other roof was EPDM ontop of which I put some old vinyl floor covering and then the compost mix.

Both roofs look great, and as Ken points out have also self seeded with various weeds and grasses

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