More people are living in cities and towns than ever before. Many of these people don’t have the luxury of a traditional garden but many do now have the opportunity to create a roof garden.
A roof garden is a great way to create extra living space and enjoy the benefits of a calming green garden in the middle of a hectic environment. Wouldn’t it be nice to come home after work and spend a few hours chatting in your own personal oasis or invite your friends to an alfresco rooftop garden party?
Pot plants and outside seating are easy first steps to creating your rooftop garden but to achieve that ‘real garden’ look and feel artificial grass is the perfect answer. It is one of the best green roof surface products available on the market for it is durable, drains well and requires little to no maintenance. You also don’t have to worry about getting a water supply to the roof if you were using real grass.
Generally roof spaces can look pretty bleak before a roof garden is installed. They tend to be an expanse of concrete, bitumen, felt or decking.
Here we take our extensive knowledge from fitting artificial lawns on hundreds of rooftops and explain how we go about installing artificial grass on a roof garden.
1. Check the drainage of the roof
The drainage of the roof must be good now and for the lifetime of the artificial grass otherwise flooding will occur when the artificial grass is laid. If drainage isn’t good a few hours work using a Self Levelling Compound can fix many drainage issues.
2. Will the roof be able to carry the extra weight?
You will need to check that the correct joists are below the roof to carry the additional weight of the grass, people, furniture etc that will be on the roof. You would be amazed where some people have wanted to send me! If you are unable to assess this yourself get a architect or structural engineer to help.
3. Is the rooftop area safe?
Are there suitable barriers around the rooftop to prevent people falling over the edge? This is especially important if you a considering allowing kids to use this space. You will also need to make sure nothing can be blown off the roof garden injuring people below.
4. Be careful not to cut the roof surface
If you are installing the grass on to felt or bitumen I suggest you place wooden boards down first and then lay the artificial grass on top.
5. Put very little glue on to the roof surface
If you glue directly on to the roofs surface use just a small amount of glue as it can cause drainage problems. We use Astro Pro Joining Adhesive to get a solid bond.
6. Use marine ply or an underlay on decking
If you are laying on to a decked roof – the decking can be either replaced with marine ply for a smoother finish or you can use an underlay. I don’t recommend shock pads because it is very difficult to get a fixing to them. If the decking is in relatively good condition you should be able to lay directly on to it.
7. Use joining tape to bind the grass together
We always use an Artificial Grass Turf Joining Tape on any roof terrace when joining the grass together as we are trying to use as little glue as possible on the roof.
8. Check the access to the roof garden
From my experience most roof terraces are hard to access so I suggest cutting the artificial grass in to smaller pieces before trying to get the artificial grass to the roof. There are still people who believe they can get a 50 sqm roll of grass up the stairs and on to the roof in one bit!
9. Roof gardens can be windy places
We sand the grass with Kiln Sand once it is installed remembering to place more around the edges to prevent flapping from the wind. We suggest placing plastic planting containers around the edges of the grass for shelter and as another means to weigh the grass down. Lattice fencing can also be used as a windbreak.
If you keep these things in mind when creating your roof garden you will have a great area to escape to for many years to come.
Any of our grasses from our artificial grass range can be fitted on roof gardens.
It has taken me many years of hard work to be able to provide the type of artificial grass installation service we now offer. Because of the enduring attention to detail and the dedication of my team I am in the enviable position of receiving many requests from people all over the world looking for help with their artificial grass installations. Whilst this brings a huge smile to my face we are still only a relatively small family owned and run business with limited resources. We currently offer our services within Kent, South East London, Hertfordshire, Essex and parts of Surrey. Whilst I am happy to answer general questions in the comments section below from anyone it may take up to 1 week for me to get back to you. Please make sure you have read other readers questions and my answers first as your question may have already been asked.
Priority will be given to answering questions from people looking for Perfect Grass to fit and supply our own artificial grass products. Please fill out the quotation form or call us on 020 81664168
For others looking for a priority response to a specific question relating to their own installation a £50 consultation fee is charged. My goal is to respond within 48 hours in these circumstances. For this specific online assistance please email me at info@perfectgrassltd.co.uk with your questions. I often require photographs to accompany your question in order to provide the best answer.
I am purchasing a property which has a large flat roof, we are checking the joists under it as we are doing some work, and will add joists is required. The flat roof isn’t even, some raise areas, what is the best system to create a flat surface to place the grass on top, not all the area will be used but I feel this will protect and be better for this large flat roof, doing it all.
A small section will be an area to sit out and for my small dogs to go out onto as there is no garden, a barrier of course would be used but again whats the best way to secure this in place.
Hi there , you can either work with what you have , using levelling compound in areas to remove any likely puddling, however the grass will mirror the shape of the roof. The grass can be attached by simply gluing around perimeter leaving gaps for the water to escape . We always under glue as it can be an issue if you ever wish to get the grass off for any reason , kiln sand can also add weight to hold it in place . The other way would be to create a wooden frame work and use marine play with drilled drainage holes in it , then simply fix the grass to this by using nails/screws. The only down side about this method is the weight you are adding on top of the joists and you would need to have this checked. regards
I have a roof terrace at the moment. I have a decked area with a fence around it. Then there is a section with astroturf which is not fenced, but there is a small wooden perimeter, maybe like 6 inches around it holding down the astroturf. I want to change the fence to go around the whole lot so I can easily walk on to the astroturf bit without climbing over the fence. I’ve been told conflicting things to do. One person by phone call told me I will need a structural engineer and permission from council (he hasn’t seen any photos). A different roofer came and looked and said he would need to seal the astroturf with a lead flashband so that water won’t collect in the middle underneath, so making it waterproof I guess and then get a fencer to change the fence. He would give me a 10 year guarantee. He said I wouldn’t need to bother with a structural engineer. Do you know if it is ok to do this?
Hi I’m really sorry we are artificial grass installers and we don’t get involved with anything structural .Regards
Hi. I have a flat roof on a back extension of my house with double doors leading onto.
I am redoing the roof as it is old and I was going to deck on top. How we. Am thinking of putting down artificial grass.
My neighbour informs me I would need planning to put down decking as it would qualify as change of use although I will not be using it as a terrace. Does the same apply if I put down fake grass? Many thanks
Hi there, unfortunately this is something you will need to ask your local planning department. I assume by putting a deck on it, it shows you will be using it as a terrace, don’t forget a lot will depend on the depth of joists below the roof whether this is feasible anyway.
Grass can be used to improve the asthetics of an area without it being used as a terrace. However again I would check first.
regards
Hi I have a bricked garage/outbuilding at the back of the house with an abestso sheeting for the roof. Due to costs of having it removed can I just leave it and put fake grass on top of it?
Sorry its a big NO! Firstly never go anywhere near asbestos , how are you going to fit it with out standing on it? Asbestos was not designed to be stood on .
Secondly how will you attach the grass to it with out breaking the asbestos which is extremely dangerous. My advice is leave it be ,until you can afford to have it professionally removed.
regards
Hello Simon,
We have two flat roofs, one of them with sedum plants that look very unhappy. We would like some green on both roofs so I have decided to go for a simple top layer of artificial grass instead just for the look as they are not walkable roofs. They have to repair both roofs and will put felt. Do you recommend that the grass blanket has holes? The ones that I have seen seem to be laid on a pretty sturdy rubber mat. Many thanks, Cristina
Hi there you can lay directly on the felt , being very careful not to score it when fitting . The grass can be lightly stuck to hold in place.
regards
Hi can i put artificial grass over a rubber roof roof covering and how do I hold it down
Hi yes you can, fixing it is a different matter though. Ideally we always look for natural fixings i.e. lead flashing around side where we can tuck etc.
If there is no where for this you will have to decide if you wish to stick using an exterior glue, we use Aquabond by Envirostik. It is extremely strong, so use as little as possible around perimeter, leaving gaps for water to escape, especially by the designated drainage areas i.e. if you glue the grass heavily along the drainage gully you will having a lot of issues!
If sticking isn’t filling you with confidence, as you feel you may need to access the roof, I would simply fit the product carefully, DO NOT KNICK THE ROOF WHEN CUTTING and then heavily sand using Kiln Sand, simply brushing it evenly into the grass and using the weight of the sand to hold it in place. Strategically placed pots can also help around the perimeter.
regards
I want to put fake grass down but there’s clay can I use wooden boards to cover the clay then put the fake grass down
No no no no !
Sorry you need to dig it out down to 5-6 inches if the clay is very heavy and build up with Type 1 .
regards
Hello. Can I ask what kind of sand would you use?
Hi the only sand we use is for top dressing the product on top, which we use kiln sand.
Hello – I have a flat roof with a silver/white protective coating. When I moved in 6 months ago I removed the astroturf that was already there as it had moss growing through it and had an eggy aroma in parts. The roof was surveyed a couple of years ago and the roof is in a good state. The previous Astroturf had sand beneath it but I’ve seen a couple of shock-absorbing mats that also allow water to drain through them. Are they a good idea? and should I get one with a latex backing? I’d really appreciate your advice – thank you!
Hi there if the roof is in good condition I would not bother with anything underneath simply roll your grass out. What you have to decide is how you fix the grass down around the edges . A simple line of glue around the perimeter allowing intermittent gaps for water to pass out . Do not over glue as you may wish to lift it one day and be careful not to knick the roof when fitting. Regards
Thanks Gavin!
What is the name of the glue you use for sticking the grass down please?
We use a product called Aquabond made by a company called Envirostik, however they are a trade seller and you can’t buy small amounts. Regards
Hello.
We are about to purchase a commercial Let.
The flat above our shop has artificial grass completely covering our back extension of the shop (10 metre by 8 metre flat roof extension with felt covering)
There is a leak in the flat roof now dripping into our shop!!
I’m worried the grass won’t be allowing for evaporation of rain water/ snow and causing our roof to have to carry more water than it was designed to cope with.
The flat roof is laid with felt and I’m worried the grass is causing water rentention and subsequently a leak. There is also no way to inspect the flat roof from above as it is covered in grass!
Do you think I should ask the tenant above our shop to remove the grass or will the grass not be causing a problem?
Look forward to your reply,
Thanks for your help
Hi yes this is a real issue that obviously needs rectifying. The grass if laid properly shouldn’t be a problem as long as the roof was in good order before ie no heavy puddling and completely intact.
What you will probably find is it has been heavily glued down and the glue is preventing water passing under it and draining away. The other cause may have been when it was installed they may have ‘knicked’ the felt causing the leaking.
Unfortunately if they have heavily stuck it down it will make one hell of a mess to your felt roof as the glue usually used is extremely strong as it has to grab hold of the latex backing of the grass.
We always let customers know the potential issues involved when being asked to fit on such a surface.
The only way forward is to try and peel the grass back in the region of the leak and investigate, however this may be harder than you think and could permanently ruin the grass, causing issues with the neighbours.
I would hold off until the issue is resolved.
regards
Hi
I have a flat balcony roof above a bedroom I’d like to cover with artificial grass, I’m worried about standing rainwater being trapped between the grass and the roof covering, would you suggest leaving an air gap?
Hi, the grass does not trap water. If the roof is free draining there should be no issue, simply fit the grass being careful not to over stick allowing water to pass across it underneath to get to the drain.
If the water does puddle this will need rectifying first, if it is only minor puddling try using a self levelling compound.
The grass effectively will mirror what ever the surface it is being laid upon.
regards
We have layer the article grass on felt roof do I need to put sand on grass. Thank you .
Hi there, only if it needs it, i.e. have you stuck round the edges?
If no then put some on for weight, if yes then has it got any puffing?
If yes then put some on these areas if no, I wouldn’t worry.
Please take into consideration the extra weight of the sand and what joist sizes are underneath.
regards
Can I just put it down like one would a large mat temporarily, with heavy pots weighing it down, I don’t want to fix the artificial grass to my flat roof which I sit on, it is covered with Sealoflex – I just need something to cover it for the summer months. Your help would be appreciated. Thanks
Hi sure just depends on the size of grass you want as it is very heavy , but in a smaller size sure this will be fine.
can I lay on top of a felt roof
hi , yes its fine but be careful when cutting as you do not want to score the felt.
Also you need to consider how you wish to attach the grass as if you over stick it you will not be able to remove if there is an issue with the roof.
We have a metal shed and would like to cover the roof with artificial grass. Can you please advise us if and how we can do this ?
Kind regards
Annette
Hi sure as long as you are happy to stick the grass to it ,its simply a case of cutting grass to size and sticking down with an exterior adhesive.
I have lots of offcuts which are cheap but are collection only.
I would advise a shorter piled grass like our grass The Outfield as it would put less weight on the roof.
best regards
Hi yes sure simply stick the product down with an external glue.