Extensive green roofs, particularly ones created using a lightweight sedum blanket such as Enviromat are typically based on a shallow layer of specially formulated growing medium known as substrate.  Green roof substrates purposely don’t contain a lot of organic matter for various engineering reasons.  That means that once the plants have finished their spring growth spurt, flowered and set seed they will have used up most of the nutrients in the growing medium and will be hungry for more.  If the plants are to be ready to survive the winter, they need to be in tip top condition.

So can you tell if your sedum roof needs feeding?

• Have you had plenty of flowers this summer?  If flowers on your roof were in few and far between, it's likely that your roof has been hungry for some time and needs some TLC in a hurry.   If you’ve had a really good floral display, plants will be heading towards exhaustion and will benefit from a light feed in the next couple of weeks.
• What colour is the foliage?  At this time of year, and with all the rain we’ve had lately, sedum leaves ought to look like plump green jelly beans.  If the foliage is bright red all over the roof;or worse, if there aren’t many leaves at all, your roof could be in a muddle.  Please send us a photograph and ask for advice before you do anything else.
• Are there any bare patches between plants? A healthy sedum roof will have a lovely thick sward of plants at this time of year with hardly any gaps between them.  Again, please send us a picture if you feel plant coverage is particularly poor. It probably means that the roof is overdue for a feed but there may also be underlying problems such as issues with shade or drainage.
• Weeds: a few weeds at this time of year are to be expected, particularly after the rain we’ve had.  It's not unusual to have a few grass plants amongst the sedums but a real infestation of grass or moss needs treating.  Be sure to pull out any tree seedlings this autumn and if you’re worried about weeds, please email a photo to our Production Manager who will be able to advise you on how best to control them.  Remember…..on an extensive green roof, weeds could indicate a problem with drainage or they could be a sign that nutrient levels are not quite right.
• When did you last feed your roof? Sedum roofs need feeding at least once a year. Twice a year if we have high rainfall or if the roof-pitch is greater than 10 degrees.  If you’ve not applied any sedum feed since January or February this year, you’d be well advised to give it a feed this summer.  If it’s been longer than that, it definitely needs attention…and the sooner the better!

What to feed

Enviromat recommends that you use Nutrifusion spring summer feed at a rate of 30g/m2 to give your green roof a boost.  Apply it any time between the beginning of march and the end of September.  One application per year is normally enough but if the weather has been particularly wet, the roof is steeply pitched or the plant layer is in poor condition, two applications may be needed.

The garden titled making a splash, designed by landscaper Jackie Knight, was designed to celebrate her 20 years in the landscaping business as well as her 20th wedding anniverary. It included garden features that are favourites with Jackie and her clients.

Jackie's trademark sandstone rock and water garden featured a stone bridge that crossed a stream that lead to an outdoor entertainment area. A wooden summerhouse featured Enviromat Sedum living roof mat supplied by Turfland / Q Lawn. A MeadowMat wild flower lawn lead up a bank to the source of the water feature where water tumbled down over rocks to a central pond. A brightly coloured planting scheme complimented the garden.

Enviromat looks beautiful on a roof or on the ground and Lovania nurseries created a beautiful display at this years Southport Flower Show in both as aspects. The alpines grown by Lovania complement the sedum and make a striking display.

Sedum used as a ground cover looks dramatic amongth the fine gravel

As a living roof the skys the limit, from bird tables to summer houses.

Through hard work and determination Mark Horton transformed a derelict 18th century folly into a luxurious family. Half way through the project as the pressure became too much he suffered a massive heart attack but came out fighting and completed the project. This unique property is a credit to him with the original building merging into a subtle extention surrounding a stunning courtyard.

At the start of the project, a folly in a field.

Old merges into new.

Newly installed sedum roof.

In full flower August 2012.

New Charter Landscapes featured a Sedum Enviromat living roof at the Tatton Flower Show 2012. The garden, called "Dream Scheme" illustrated two seasons and they wanted to incorporate a sedum Enviromat roof. Turfland provided two slabs of Enviromat, one with pink flowers and one with yellow flowers which was perfect to fit in with the garden theme.

Winter half of the garden, pink side of the sedum roof.

Summer half of the garden, yellow side of the sedum roof.

Enviromat and
Survival of the Fittest

Q Lawns' representatives Kevin Harden and Mark Gurney will be joining delegates and exhibitors at Palmstead Nurseries’ soft landscaping workshop “survival of the fittest” on 27^th September.

Kevin and Mark will be showcasing Enviromat sedum matting for green roofing and low maintenance ground cover and Meadowmat wild flower matting for ground use.  Both products have been designed with wildlife in mind and have a host of environmental benefits.

Palmstead Nurseries’ workshops aim to inform, educate and inspire and this year’s event promises to be excellent.  Combining scientific research, hands-on experience and interesting design ideas, the day-long seminar program offers excellent value for money at just £21 per person…which includes lunch and refreshments.

Showcasing Enviromat and Meadowmat

Q Lawns will be exhibiting live products, so while you’re enjoying your complimentary refreshments, please seek out Kevin and Mark (situated in the corner of the Kent Suite) and take a good look at Enviromat and Meadowmat. 

Enviromat is our UK grown sedum matting.  A mixture of six low growing sedums with a smattering of Meadow Saxifrage, Enviromat produces nectar rich flowers from April to October (weather permitting).  Because the matting system contains all the growing medium these little plants need, Enviromat can be installed on to soil-less areas such as roofs, patios, rock gardens or slopes and it also makes a fantastic alternative to a grass lawn in low-traffic areas.

As a living roof material, Enviromat is probably the least heavy of all green roof build-ups and one of the easiest to install.  In fact, the company offers a green roof installation service for anyone not confident working at heights.

Meadowmat is grown on an adjacent field to Enviromat on Q Lawns’ farm on the Norfolk/Suffolk border.

A mixture of 30 native flowering species and 4 native grasses, Meadowmat seeks to provide a rich source of nectar for bees, butterflies and hoverflies as well as habitat for a wealth of small creatures.

Not only does Meadowmat produce a wonderful floral display through late spring and into summer, it’s easy to install, gives more reliable results than seeding, and has a low cost maintenance regime. It’s perfect for local authorities looking to save money on grassland management.

As an added bonus, Meadowmat improves with age; properly managed, it will become more biodiverse and more colourful every summer.

Contact Q Lawns for more Information

For more information about either product…or indeed about Q Lawns turf, topsoil or sundry landscaping products; please call the office on 01842 828266 or email Angelal@qlawns.co.uk with any questions you may have.

Green Roof Training

Angela Lambert from Enviromat will be talking about Green Roofing and wild flower meadows at the APL networking seminar at Classiflora, Essex on Wednesday 06 March 2013.

The theme of the seminar is Ethical and Sustainable Landscaping and looks at green roofing, urban greening solutions, sustainable urban drainage systems (SUDS) and using the right plants in the right places.

Places cost just £15 + vat per person for APL members or £30 + vat per person for non-members

For further infomration contact the APL events team by emailing events@the-hta.org.uk or calling 0118 930 3132 for more information.  

Or visit the event page on the hta website  

4th february 2013

The snow has gone; spring will soon be with us. Now is the time to plan those jobs that need doing around the house and garden.

Some of you may be contemplating having a new shed or even a new summer house, if you are, there is more to think about then just what colour to paint it.

I am going to tell you about the benefits and joys of having a green roof.

Benefits of a green roof

There are many benefits of having a green roof; I have listed some for you here.

It will attract and support wildlife, without pollinating insects we will have no food.

 It also insulates your building from heat and cold, resulting in cheaper bills.

 Just having a green roof extends the lifespan of the waterproofing layer; it can help to double the lifespan of your waterproofing layer.

A major benefit of a green roof is that it drastically reduces the amount of storm water that is put into our sewers and waterways. This is vital to everyone, as global warming raises sea levels and flash floods become more frequent throughout the country.

It can also reduce the noise from outside; ideal if you like somewhere quiet or you live in a busy city centre. It’s also a great idea for recording studios.

And the most important thing, it looks fantastic all year round with flowers blooming from spring right through to the autumn.

Kevin Docherty is Green Roof Manager at Enviromat.  Working throughout England, Scotland and Wales, Kevin installs small sedum roofs on buildings such as garden sheds, summerhouses, home-offices, porches and extensions.  Kevin also helps commercial facilities managers to get the full benefit from their green roofs with bespoke green roof maintenance regimes.

After the second wettest year on record with over 8,000 homes and businesses affected by flooding, the time has come for green roofs to take centre stage.

A green roof can reduce storm water run-off by up to 80%, this reduces the amount of water being pumped into our waterways and rivers.

I am going to tell you how to `green’ a pitched roof.

Whether your roof is big or small there are a few major factors in deciding to have a green roof:

1)      Can your roof take the extra weight of the green roof?

      Your roof needs to be able to withstand the weight of 120kg per square metre.

2)      Is the waterproofing on your roof in a good condition?, Does the roof drain away properly?

      To repair leaks once the sedum matting is installed is very expensive.

3)      Is the surface of your roof flat and smooth? Air pockets can lead to dead patches.

      The matting will settle onto small hills and bumps, but will not cope with sudden changes such as corrugated tin roofs.

Now that you know your roof is suitable for `greening’, let’s get started with the good bit.

Firstly let’s make sure you can access the roof safely, scaffold towers and hop-ups should be used. Always take extra care when working at height, even relatively low heights.

Final check if the waterproofing is sound, get your hosepipe out and soak the roof, keep checking inside for leaks or damp patches.                              This is your last chance to check before it gets expensive!

The roof will need some form of edging to protect the sedum from `wind uplift’; the edging must still let excess water drain away.                                 

Once you know its water tight we can start to build up the layers we need for the green roof.

The first layer you will need is a good quality, strong root barrier, something along the lines of a poly butyl pond liner.

The next layer before you get your hands dirty is the water retention mat, this lightweight inexpensive fleece holds 9 litres of saturated water per square metre, this is vital to keeping your roof looking great for years to come.

Now is the time for the sedum blankets, make sure you can lift the sedum onto the roof safely, it may need 2 people to lift it up onto the roof.

Roll the sedum blanket out making sure you have got the blanket as close to the edging as possible, once it is rolled out, remember to unravel the extra piece of matting and lay it flat on the roof. This extra piece helps to secure the sedum to the roof

Repeat as above, remembering to start the next roll tight up against the previous roll, on top of the extra piece of matting.

Once you have got to the point of trimming your sedum matting, carefully mark the roll where it needs to be trimmed. Make sure to cut the blankets from the non-vegetated side.

Make sure all edges are pushed down along the edging strip and all joints have no gaps.

Once you have your green roof installed make sure to water it, especially if you have installed the green roof during hot weather.

If you prepare fully and follow these simple steps, you too could have a fantastic looking green roof.

Once your green roof is installed, you MUST keep it maintained or all your hard work would have been for nothing.

Kevin used materials available from www.enviromat.co.uk to create his living green roof

updated 4th February 2013 by Kevin Docherty

 updated 6th february 2013

Do we want to live in water world?

With global warming affecting sea levels, storm water runoff being pumped into our rivers and waterways and planners with developers building on flood plains for new housing, it is no coincidence that we are increasingly seeing more flooding around the U.K.. The problem will only get worse as global temperatures rises, but there are solutions to the problems we face.  The easiest by far is to create a green roof, no need for expensive water harvesting systems or a space big enough to put a storage tank in your garden.

A green roof can reduce storm water run-off by up to 80%, this reduces the amount of water being pumped into our waterways and rivers.

I am going to tell you how to create a green roof. This is for flat roofs only.

Whether your roof is big or small there are a few major factors in deciding to have a green roof:

1)      Can your roof take the extra weight of the green roof?

      Your roof needs to be able to withstand the weight of 120kg per square metre.

2)      Is the waterproofing on your roof in a good condition?, Does the roof drain away properly?

      To repair leaks once the sedum matting is installed is very expensive.

3)      Is the surface of your roof flat and smooth? Air pockets can lead to dead patches.

      The matting will settle onto small hills and bumps, but will not cope with sudden changes such as corrugated tin roofs.

Now that you know your roof is suitable for `greening’, let’s get started with the good bit.

Firstly let’s make sure you can access the roof safely, scaffold towers and hop-ups should be used. Always take extra care when working at height, even relatively low heights.

Final check if the waterproofing is sound, get your hosepipe out and soak the roof, keep checking inside for leaks or damp patches, adding food colouring to a watering can will help to find leaks.

This is your last chance to check before it gets expensive!

The roof will need some form of edging to protect the sedum from `wind uplift’; the edging must still let excess water drain away. Edging can be bought from certain suppliers.

Once you know your roof is water tight we can start to build up the layers we need for the green roof.

The first layer you will need is a good quality, strong root barrier, something along the lines of a poly butyl pond liner.

Next up is the drainage layer; this layer can come in a few different designs. Some have an egg cup design with small water reservoirs throughout but these are un-flexible, others come in the form of a filter mat.

The next layer before you get your hands dirty is the water retention mat, this lightweight inexpensive fleece holds 9 litres of saturated water per square metre, this is vital to keeping your roof looking great for years to come.

Now is the time for the sedum blankets, make sure you can lift the sedum onto the roof safely, it may need 2 people to lift it up onto the roof.

Roll the sedum blanket out making sure you have got the blanket as close to the edging as possible, once it is rolled out, remember to unravel the extra piece of matting and lay it flat on the roof. This extra piece helps to secure the sedum to the roof.

Repeat as above, remembering to start the next roll tight up against the previous roll, on top of the extra piece of matting.

Once you have got to the point of trimming your sedum matting, carefully mark the roll where it needs to be trimmed. Make sure to cut the blankets from the non-vegetated side.

Make sure all edges are pushed down along the edging strip and all joints have no gaps.

Once you have your green roof installed make sure to water it, especially if you have installed your green roof during hot weather.

If you prepare fully and follow these simple steps, you too could have a fantastic looking green roof.

Once your green roof is installed, you MUST keep it maintained or all your hard work would have been for nothing.

Watch our video on how to install a sedum roof

 updated 21st february 2013
by Angela Lambert

Enviromat are proud to announce that the Royal Horticultural Society has given us permission to associate Enviromat sedum matting with the RHS Perfect for Pollinators logo.

Pollinating insects are in decline

The number of pollinating insects such as bees, butterflies, hoverflies and moths has been in decline for at least 50 years.  In that time, at least 2 species of bee have become extinct and according to a recent study conducted by the Zoological Society of London, Bumblebees, beetles and butterflies are at greater risk of extinction than lions and tigers.

A pollinator is a creature that transfers pollen from one plant to another, allowing flowers to become fertilized and able to produce seeds or fruit.  Around 1/3 of the food we eat has been produced with the aid of a pollinating insect….so they’re awfully important.

The problem for these creatures is that they cannot feed solely on our food crops. That would be like us relying on food shops that only open during May and June.

The RHS have recognized the importance of pollinators, not just for food and farming but for ecology, biodiversity and the environment in general, and so they have compiled a list of plants that are good for gardens and good for insects too.

Enviromat is made up of several species of sedum plants and one early-flowering native plant called Meadow Saxifrage.  Bees and butterflies adore sedum plants because the flowers are flat, star shaped and really easy to collect pollen and nectar from.  Enviromat, which is great for low maintenance groundcover and for creating living roofs, contains a mixture of sedums to give a nice long flowering period.  Weather permitting; Enviromat will be a source of nectar between April and November, which means of course, that it’s perfect for pollinators.

More about Enviromat sedum matting

Why we need Green Roofs for Wildlife Corridors

Angela Lambert   9th March 2013

I recently gave a talk to a group of APL members at their networking seminar that was entitled "ethical and sustainable landscaping". I was given the brief of to explaining how green roofs and wild flowers fit into a sustainable landscape and guess what - it was really difficult; not only because I find public speaking a bit of a challenge,  but because I had a 20 minute time slot and was going to struggle to say everything I wanted to in such a short time.

Green roofs, we'll designed, properly installed and carefully maintained are super sustainable and of enormous benefit to wildlife, to the environment and to whoever or whatever uses the buildings they are on.  For this blog spot I'll concentrate on the way in which green roofs create wildlife corridors and why that's so important to humans.

Around one third of our food depends on pollinating insects such as bees, moths, butterflies and hoverflies.  Without these tiny volunteers we would have no apples, plums, courgettes, tomatoes, beans, onions, cucumbers or cabbages - we'd also be short of flowering plants and oh my goodness, wouldn't we have to pay high prices for our 5 a-day!

Over the last few decades, scientists have recorded an enormous decline in the numbers of pollinating insects and there is a worry that if pollinators keep disappearing, it will become more and more difficult go feed the rising population of people know this country.

 Two of the factors that are affecting pollinating insects are a lack of suitable food plants and long distances between colonies.  In other words, man has either built on or cultivated so much land that our small helpers can't find enough to eat when the food crops have finished flowering. Neither can they travel to the next colony to mate with partners that are not close relatives.

 A wildlife corridor addresses both of these problems and needn't be an inconvenience to us people.  If every street, motorway, fenceline, hedgerow and riverbank were lined with nectar-rich flowers, laval food plants for caterpillars and resting places for tired critters, our pollinators would all be much healthier and happier. 

If planting at ground level is not practical eg in towns or where gardens have been paved over for parking,  green roofs make great service stations for flying creatures.   Enviromat sedum matting is frequently used to create green roofs on sheds and garden offices and has recently been approved by the RHS to carry the RHS Perfect For Pollinators logo. 

It isn't difficult to create a green roof for wildlife using Enviromat....check out our installation page for a more information or read more about green roofs for wildlife.            

by Enviromat
26th March 2013

Spring time is late getting here this year and we're all desperate for a little sunshine in our lives.   Here are some pictures of Enviromat sedum matting taken in 2012 as a taste of what's to come (I hope)

Sedum album:  White Stonecrop	Sedum pulchellum: Widow's Cross Stonecrop
path edged with mixed sedums	mixed sedums on a roof
Butterfly on sedum spurium	seed heads

By Enviromat: 27th March 2013

How much does a green roof weigh?

This is something that our customer service team is asked almost every day and it’s probably the most important green roofing question there could ever be….after all, it’s the strength of your building that determines what sort of green roof (if any) you should be installing.

A grass roof like this needs a mighty
strong building to support it

As a rule of thumb, the more biodiversity you want on a roof, the deeper the layer of growing medium needs to be and the heavier it is.  So, for example, if you were aiming to put a wild flower meadow on your roof, you would need AT LEAST 10-15cm of growing medium to support the plants that have deeper root systems.  Expect the loading to be upwards of 250Kg per square metre…which is quite a lot, especially if your building is an average garden shed.  You would probably need to strengthen the walls and the roof deck before installing the green roof build up.

An Enviromat green roof is lighter than a wild flower roof because we use specially engineered blankets for water management and because the plant species used in the matting are very shallow rooted….so they don’t need deep soils or growing media.

A flat roof, built using the Enviromat green roof system will weigh

• Drainage mat:   weight is negligible
• Water retention mat; holds up to 9 litres of water per square metre, so saturated weight is 9KG/m2
• Enviromat; when saturated with water in summer time, when the plants are at their biggest and heaviest, the mats weigh 40-45Kg/m2
• Live Loading:  ALWAYS allow a bit of extra strength in your structure to support extra weight such as snow or the maintenance man

Total weight of an Enviromat roof* including live loading is 120Kg per square metre

*installed as per our recommendations and using Enviromat components

By Robert Allen
9th April 2013

When is the best time to make a green roof?

Robert Allen, Sedum Production Manager at Enviromat, has been growing green roof plants for the UK’s leading green roof installer for around 15 years and has been involved with all sorts of green roofs, from teeny tiny ones to huge installations. In this blogpost, Robert offers some advice about timing to ordinary folk who want to create a simple green roof.

1. Health and Safety is paramount.   Don’t try to work on a roof in very wet or windy weather.
2. If you want your green roof to flower in its first summer, we recommend using vegetation mats and installing them before the end of April.  For sedum mat from may onwards, flowers will be entirely weather dependant. 
3. Enviromat sedum matting is available all year round (weather permitting) and can be installed any month of the year.
4. Plug plants and seeds can take a while to fill in all the spaces so be prepared to wait for your roof to green up and start flowering. The sedum mat and the wild flower mat that we grow at Q Lawns will be delivered to you with around 95% plant coverage.
5. NEVER store sedum matting rolled up.  If you can’t install it on the day it’s delivered, unroll it and let the plants see daylight.   Enviromat can normally be delivered within 3 working days of an order being placed so that you can co-ordinate your delivery with the weather and your workforce.
6. If the weather is very hot and dry when your sedum mat is laid, be sure to water it once a week until it rains but BEWARE of over-watering. 

In short:

For speedy and reliable results:  Use sedum matting or, if you have a deep substrate base, wild flower matting.

Install in spring or autumn in an ideal world – but any time of year is OK provided it’s safe to work on the roof

Watch our “how to” video and make sure the building and the roof are prepared before you order your green roof build up

Contact us if you have any questions or if you need help to install a living green roof on your garden building

Angela Lambert
16th April 2013

Watering a sedum roof

As a nation of gardeners, we are generally quite enthusiastic about watering our plants to keep them in good health.  The trouble is, it’s very easy to get it wrong.   I’ve lost count of the number of houseplants I’ve killed with kindness and the number of vegetable plants that have produced pathetic crops because I’ve been lazy with the watering can is probably well into double figures.

Water requirements of sedum roofs

A sedum roof is a different animal altogether.   Think of it as a giant sized butler sink crammed with alpine plants but lifted high off the ground – too high for everyday access.

An outdoor, container grown alpine garden at ground level is very self-sufficient, provided that it has the right soil type and the right drainage.  It rarely needs watering, the British weather does all that and although it relishes a light feed in spring time, it more or less cares for itself.

A sedum roof is just the same.  Provided that the right drainage and growing medium have been used, the roof slope is not too steep and the plants are given the right food in springtime, an established sedum roof will care for itself without a water-guzzling irrigation system.   In fact too much water is worse for the sedum plants than too little water.

Sedum plants are very drought tolerant because of a built-in metabolism called CAM  or crassulacean acidic metabolism.  In terms of green roofing, this means that sedums can thrive in a shallow layer of growing medium where other plants struggle to survive.  This provides a bonus in that on a normal year, any weeds that manage to germinate on a shallow substrate sedum roof,  will generally die of thirst - provided that we humans don’t alter the conditions and make the roof weed-friendly.

When to water a sedum roof

Like all plants, an Enviromat sedum roof will need watering until it is established, but will be independent after that.  Too much water will encourage weeds. Only water your Enviromat roof if your roof is very windy and dries out quickly, if the slope is greater than around 10 degrees, or if, during a drought, the leaves start to look like wrinkled balloons.  Other than that, let nature do the work for you.

New delivery vehicles for Enviromat

Enviromat sedum matting is generally considered to be quite an eco-friendly product and so when the Directors of Q Lawns turf growers - who produce Enviromat on their farm in Norfolk - had the opportunity to reduce the carbon footprint of their delivery vehicles, the jumped at the chance.  

This week, the Company took delivery of four DAF XF105 460 ATe lorries.  The manufacturer claims that these vehicles can achieve a 2-3% reduction in fuel consumption and have greatly reduced carbon emissions due to some innovative improvements to the engine.

Every truck needs a driver and so Q Lawns are also pleased to welcome  Alan, Alvin, Paul and Martin to the team.   Alan is well known to Q Lawns customers, he's joined us from E&SJ Walpole, the other three boys are experienced drivers but entirely new to the Company.

Director Colin Brown is proud to be embracing new technology in transport.  He says “I'm keen to minimise our environmnental impact and that means thinking about what happens off the farm as well as managing wildlife habitat and making best use of resources on the land and in the office”. 

Sedum matting price drop

Good news for anybody thinking of creating a sedum green roof this summer.  The price of Enviromat sedum matting has been permanently reduced with effect from 26^th April.

Chris Carr, Sales and Marketing Manager for Q Lawns – the growers of Enviromat sedum matting explains.  “Green roofing is becoming more and more popular year on year” he says “and a change in mindsets mean that buyers want UK grown products rather than European imports.  Consequently we’ve had to increase production of Enviromat, which means that we can   make savings due to economies of scale.  We’re passing those savings on to our customers”

Angela Lambert added “Green roofs offer so many benefits, not only for the building’s owners and occupiers but for the wider environment too.  Popping an Enviromat green roof on to a shed, a summerhouse or even a rabbit hutch, will create a source of pollen and nectar for our butterflies and bees – most of whom are declining in numbers.  Hopefully, these cost savings on Enviromat will help make green roofing more affordable.

What does a green roof cost?

For a quote for the materials you'll need to create a sedum green roof,  phone the Q Lawns office on 01842 828266 and talk to Rebecca.   The office is open from 7am - 5pm on weekdays.  Or you can visit the online shop 24/7

How much does a sedum roof cost?

With the news that Enviromat has reduced the price of sedum matting by almost 20%, Angela Lambert looks at the cost of putting a green roof on your shed.

A beautiful sedum roof is a lovely adornment for any sturdy building and it’s easy to install once you know how, but the bottom line, when making any decision involving an investment in the environment is, what will it cost?

Let’s look at a typical garden office with a footprint of 10 feet by 8 feet.   We’ll assume that it’s a strong building with a very slight pitch to the roof and that all the waterproofing is in place.  That means that there are no structural changes to be made such as strengthening.

Green roof edgings

First up, edgings:   These are a matter of taste and so price is variable.  Save money by using reclaimed timber or make a statement by commissioning some bespoke edgings. - more about this in another blogpost

Green roof build-up

First determine the area by multiplying the width of the roof by the length.  Use the online area calculator at http://www.enviromat.co.uk/enviromat/ if you’re unsure – it also has a helpful ability to convert imperial measurements to metric ones.

Our 10ft x 8ft shed has a roof area of 8 square metres.

Because it has a roof slope of less than 3 degrees, it needs four layers of material in the green roof build up;

Polyethene to protect the waterproofing against damage from roots or boots

Drainage mat to ensure the sedum plants don’t languish in conditions that are too wet for them

Water retention mat to support the plants when rainfall is in short supply

Sedum matting. - the bit with the plants in.

Putting 8 square metres of each of the products above, into the Enviromat online shopping trolley, along with a tub of green roof feed, gives a TOTAL price ie including VAT and delivery of £412.08

Please note, this price is correct at the time of writing (29^th April 2012 and is for delivery to a Bristol postcode) Prices will vary depending on delivery area and are considerably less if you collect from either of our farms.

Cost of the green roof build up for a 10x8 flat roof is less than £420.00

Enviromat offer discounts on large areas and for trade customers. Email for more information

Video: How to make a sedum roof

Green roof plants with white flowers

Early may is when bees are flying strongly and butterflies are out of hibernation and looking for food.  It's also when UK green roofs start to bloom in earnest.

Meadow Saxifrage

One of the first plants to bloom on extensive green roofs is the meadow saxifrage, saxifraga granulata.  This native wildflower likes to live on well drained grassland but also thrives in shallow layers of green roof substrate.

Its name, saxifrage, comes from the Latin word for 'stone breaking ' probably because the close relatives of meadow saxifrage tend to live in stoney ground.  The species seems to be drought tolerant and because it is low growing with fleshy leaves it is quite happy on a green roof. It certainly looks lovely blooming its socks off on top of my brother's shed.

Sedum album

The Other white flowering native plant normally found on an Enviromat green roof is sedum album - the white stonecrop.  Coming into bloom just after meadow saxifrage this flower is like a magnet to honeybees and bumblebees as well as attracting butterflies who enjoy this rich source of nectar.

Sedums are well adapted for living on green roofs where there is a shallow layer of growing medium. Typically these living roofs are lighter than deep substrate roofs and are ideal for retrofitting on to existing buildings or installing on to garden sheds.  Where the building can support more weight it is possible to have a deeper layer of growing medium and subsequently a more diverse range of plants.

Other white plants for green roofs

If there is a minimum depth of 15cm of well drained green roof growing medium, other white flowers such as daisy, wild strawberry or even mountain avens should do well but beware of plants that have invasive roots - for they may ultimately damage your waterproofing - and be aware that taller plants may be damaged by strong winds.

There is work being done to assess the value of Stachys (lambs ears) on green roofs.  It is thought that the plant's silvery white leaves will do an excellent job of reflecting heat away from the roof.   Having grown stachys in my garden, I personally would be concerned about it crowding out other plants.  But that's just me.

Remember the old adage "right plant, right place ".

More about green roof plants

Meadow saxifrage and sedum album are just two of the plants included in the seedmix for Enviromat sedum matting, a fabulous material for creating living green roofs. >more