What considerations should be made when installing a green roof on a metal building?
Our building is just shy of 600 square foot, and currently has a metal roof. It has a slight pitch, but we live in east texas, are on a very tight budget, would like to do all of the work ourselves, but the extreme heat and weather we experience here in pine country has us questioning what plants are light enough, and are able to withstand the heat without an extensive root system.
When you ask about installing a green roof on a 'metal' building, you are referring to the current roof covering, correct?
We do have a DIY green roof installation video, the first steps of this process (linked below) would be the same, in that you need a waterproof roof covering, then a root barrier, and certainly for a green roof in a desert climate you would want a dimpled drainage membrane with the capacity to store water.
A living green roof can last far longer than many other roofing systems when installed properly.
We would need more details in order to provide any specific advice in your case; are you considering leaving the metal on the roof and doing a green roof on top, is that what you mean by a ‘metal building’? Are you planning on building a green roof because the metal has deteriorated? I ask this because the process would normally start from the roof sheathing, so that metal would need to come off. Please let us know your starting point, and we can help set you off on the right track.
Thank you for answering so quickly! Where we are, we actually get A LOT of rain. We are a subtropical climate in the piney woods of east Texas. I would prefer to take the metal roofing off, so that isn't an issue, my main concern is how to know what kind of weight a "metal building" built in an area with no snow would be capable of. In addition, we can get down to 20 farenheit (high humidity), and up to high 90's (high humidity) summertime. I will be saving up, and begin fundraising this year. (It is for a non-profit), so I really want to get an idea of what we're facing.
We can advise you on the general steps to take to protect a roof, but when it comes to the structure, we would not be able to offer any advice sorry. You should have an engineer determine that. It doesn’t sound like you have a ton of cash lying around and I wish we could help more, but there is no way for us to know remotely what sort of load an existing structure could handle. You could check with the municipal building department and they may be able to offer more advice than us.