has anyone attempted a green roof???

mambury

We are about to build an extension and part of it is single story and rather than have a plain, boring, flat roof I am interested in laying a green roof, preferably a low maintainance (sp?? its late and my brain is switching off!) one.

Has anyone had any experience they would be kind enough to share with me?

I've done a bit of speed googling and saved a few sites etc to my favs to read later but I would love to find out if anyone has had a go???

Thanks
Mambury

choille

It's complex - you need special membrane that are specifically designed for the job.

There are also weight issues involved - perlite is used in the soil because of that. It's very complex & requires a professional eye over it.
It needs a design from someone who knows the score - designed for the purpose.

There are books available. See if CATS has any leaflets.

Tibbie's_mum

When you said green roof, this is what I thought of........
http://www.stonesmith.co.uk/detail.php?p=4587

not what you want at all!

mambury

Tibbie's_mum wrote: »

When you said green roof, this is what I thought of........
http://www.stonesmith.co.uk/detail.php?p=4587

not what you want at all!

:rotfl::rotfl::rotfl:

slipp_digby

you will need to make sure that the roof is structurally up to holding both the vegetation, growing medium and also a signficant quantity of water.

one of the benefits of using a geen roof is that it attenuates roof run-off and this is usually held within the roof until it evaporates.

most commerical green roofs I have seen use sedum nd normally have a couple of different species only.

there is specialist design input needed on this to do a decent job.

why are you considering one?

ixwood

Why not?

I say go for it. If you have any way to access it, make it as a roof garden.

I've got a garage and a porch I was considering improvising on with some wildlower seeds...

11thcommandment

Hi, I'm building a shed/machine store at the moment with a green roof. I did the research and initially decided not to do it at it appeard to be too "technical" and very expensive (sedum matting > £25 per sqM and I need 30sqM). However - after more reading I have found out how to construct the roof, make it watertight and plant it without costing a fortune.

I have seen lots of DIY suggestions using carpet/cardboard/pvc pond liners/broken breeze blocks etc.etc. and commercial solutions costing a fortune!!

This is what I am doing:-
Usual roof construction is as per regular flat roof e.g. 6x2 or 8x2 joists - 400mm centers - depending on span, 18mm OSB3 (water resistant) for the surface, double layer if you want to push the boat out. I have used a 1/30 fall but you can go a bit steeper if necessary, the fall is necessary to ensure the water actually drains rather than forming a stagnent bog!
I am going to border the roof with 6x2 to form a 6" deep "bath" and use a fillet piece all around the inside edge just so the waterproof layer doesn't have to go up 90deg in one go.

The top bit:-
Waterproof layer - A green roof suitable membrane e.g. Firestone EPDM or equivalent.

Drainage layer 50mm - I will use expanded clay pellets (very light weight).

Filter layer to stop drainage layer getting clogged up - top quality geotex fleece 80p sqM (no value in compromising here 'cos you want this to last forever).

Growing layer ~100mm - I will use a mix of soil / vermiculite / perlite (compost is no use here).

Plants - I will probably use online supplier of alpine/sedums approx £120 for 480 plugs.

I just started a blog but haven't added any content yet, I'll share the link if you are interested? FYI I will be laying the rubber membrane this weekend if the rest of the wood to finish the roof border arrives tomorrow.

Also - do you want the list of suppliers?

Hope this helps!!

mambury wrote: »

We are about to build an extension and part of it is single story and rather than have a plain, boring, flat roof I am interested in laying a green roof, preferably a low maintainance (sp?? its late and my brain is switching off!) one.

Has anyone had any experience they would be kind enough to share with me?

I've done a bit of speed googling and saved a few sites etc to my favs to read later but I would love to find out if anyone has had a go???

Thanks
Mambury

Joly_Roger

There's a green roof visible on a public building in South East London. Horniman's Museum in Forest Hill.

The library has had a green roof for as far back as I can remember. I've always been impressed with how it has no guttering coming off it. There's also lush tropical planting surrounding the library, so it looks like an oasis of plants which is such a welcome sight these days.


Good luck to anyone creating their own, the environmental benefits are enormous In the future I hope they'll become very common.

ceridwen

Good for you - like the idea.:T

I've put various links to things to do with growing food on roofs and balconies and green roofs on my MSE homepage if you want to spend an hour - or three - browsing for the various bits I've added on this sorta topic. I've just used this "blog" to store useful info as I come across it.

Penelope_Penguin

Joe Swift built one on GW The details of ther build are sketchy, but there's a useful plant list at the bottom of this link

I'll add this to the existing thread on green rooves later.

Penny.

Lotus-eater

11thcommandment wrote: »

I just started a blog but haven't added any content yet, I'll share the link if you are interested?

Although I have no immediate plans to do anything like this atm, I'd be interested in seeing your blog.