Thinking of doing a DIY green roof on a budget on the workshop to blend in better with the orchard and wondered if anyone had any pointers and good sources of suitable plants/seeds.

Only thought about it when driving home today but so far the plan is:

1. Beef up the roof beams for the extra weight
2. Fit a thick DPM sheet (single piece (probably use some double sided tape to help stick it down)
3. A drainage mesh (weed membrane stuff?)
4. Some kind of coarse lightweight lattice to help stabilise the soil etc (have a couple of ideas)

Been looking at plants and seen some Sedum seed packs but also thinking about some moss. Have seen some irish moss seeds but also thinking about getting some local samples from the woods.

My father has a whopping wood store which is just rough poles with a roof of a mix of crinkly tin and asbestos. It has lasted about 20 years and is going well. No need for all the fancy stuff.

Some of the new green/ brown roof systems use egg crates to allow a fast uptake. A lot of the systems also have a low nutrient medium to reduce weed growth, if you can get crushed bricks/ blocks then you can mix with soil to help drainage and also reduce weight a little.

You could always put turf on there if you can cut some locally. Providing the roof gradient is shallow enough.

http://www.thegreenroofcentre.co.uk/green_roofs/diy_case_studies

http://livingroofs.org/

Get a structural engineer or someone that knows what they are talking about, water is heavy!

Mine has a layer of corrugated plastic above the membrane to aid drainage. And a layer of old carpet above that, followed by a little bit of stuff for the sedums to grow into.

Lot of weight there.

Will the roof be visible, for example from your bedroom? And does it need to look “pretty” or just green?

Turf? How on earth do you mow the grass?

Just plop on some Astroturf… 😀

What about those green corrugated roofing sheets – they look pretty rustic.

A modular sedum roof might be an option if you need to keep the weight down (loads of companies out there so I won’t post a link).

those modular tiles look to be about 50kg a sqm so if they were on the roof of a wooden outbuilding what kind of dimensions for the wood framing would you need to support that kind of load?

With green roofs, if the roof pitch is steep – lets say greater than 10 degrees – there usually (dependant on who you speak to) needs to be an irrigation system otherwise it can’t retain enough water/moisture.

Sedum type green roofs usually come in one of two types, either a pre-grown sedum mat or plug plants/cuttings. Both will sit on a 50-60mm plus of a growing medium, usually described as light weight, which is often crushed brick and aggregate. Below this is a mat which is intended to protect the roof waterproofing membrane, retain moisture and stop the growing medium washing away/filling the water retention layer. These mats start at about 20mm thickness for flat roofs, for say 15 degrees you would at least double this. There are plenty of manufacturers offering their own variations. A typical sedum mat build-up will weigh 100-120Kg/m2 when fully saturated. If you’re thinking of grass or turf then 150mm of growing medium is considered to be the minimum thickness to avoid drying out; with a large perimeter to area ratio as with a shed this risk is increased.

❗
It’s a shed not a doctors surgery.

cheers for the replies. Had another look around today and decided it was just going to be too much faff and need too much beefing up. It’s 16x10ft so not a small roof. Maybe if it was summer and nice weather then I wouldnt mind but at the moment it’s peeing down and miserable so not feeling inspired.

Have decided on green metal box section like we have on the garage, car port and field shelters so it shouldnt look too bad.