[BigD]

Hello, have any of you installed a green roof system? If so, once the building is up, for the landscaper is it as easy as placing the trays of plant material on the roof?

[Dale Wiley]

The only companies around here installing green roofs are the big boys in the millions of dollars.

These are highly engineered architectural items. We have supplied plant materials for several of these projects, and the one thing consistent is that they often have to be planted several times, there are a ton of lawsuits on every one of these involving the contractor, owners, architects. I don't extend ANY credit terms to most of these companies for the plant materials.

You have to have one hell of a credit line to do these projects. You may get some good pub out of it, but pub don't pay the bills.
I am highly content to supply the plant materials, and even that is becoming very specialized.

[Stonehenge]

I swear I can’t swing a dead cat without hitting something about Green Roofs lately. It’s the lead story this month in Total Landscape Care magazine. I believe it’s been in Landscape Architecture magazine a few times recently. It seems to be everywhere. Sounds like something that’d be up Bill Schwab’s alley, renting a helicopter to bring plants to the top of a building or something.

Are you looking at a bid for that kind of project?

Here’s an Image Search for Green Roofs. Also, if you look at www.Greenroofs.org, you’ll see there’s a class in your town TOMORROW. Twist some arms and get over there.

[BigD]

Stonehenge: I am looking at some plans and it calls for a 50% green roof, but the only useful information it has is on the supplier of the trays and where they need to be placed. I wish I had time to go to that class that you mentioned...a little more lead time and I probably would.

Dale: I think I know some of the types of projects that you are refering to and this is not as nearly as complicated, the plans I have are for a small retail building.

[Stonehenge]

I think there's more to it than just sticking trays of plants up top; I believe the expectation is that there is a growing medium (ie soil) for the plants to grow in. Do they reference any specs to define what "green" is?

[trees]

Sounds like it was designed by someone with a design/build firm that wrote the specs to tailor their own company. I'd do it that way, too. Make the specs ambiguous and include just enough to give your company an edge in the bidding process.

I think you need more information to bid on it wisely. Green roof systems are highly complex and take a lot more than plants up there.

[Terre]

Here's a scary one, I actually got a call from someone about this today. They saw an episode about this on HGTV "Gardening by the Yard" and want their garage done!

Quote: "It didn't look that hard on TV?"

I told them structural engineer and they ran backwards.

I have this mental picture of all these DIY'ers trying this at home.

[Dale Wiley]

Terre hit it right on the money " STRUCTURAL ENGINEER".

These have to be designed by a structural engineer because of the loads, etc drainage.

One of the projects we supplied plant materials for, crows and other birds found some our our plants to be very desirable for nesting materials and were removing the plants.

Big brew haha between owners, contractors, engineers that involved cameras, who's going to replace what and who's is going to pay for it.

We have seen this evolve over the last few years and Jesse hits some very valid points.

Building size has nothing to do with the overall concept of having a qualified LA or CE design the load parameters, media, drainage and structural needs.

[BigD]

I agree with you entirely and engineers were involved in the design process, but the specifications were terrible. I believe I found some of the answers that I was looking for, thanks to all.

The DIY'ers doing it on their own homes is a rather scary thought.

[dan deutekom]

I did one for a very rich "Hippy environut" about 12 years ago. It was for his "Cottage". This was a very upscale building of about 3000 sq, ft. It was of straw bale construction that was covered with stucco. It was heat by wood stove. We were contracted to put 6" of good topsoil on the roof and then seed with wild flower mix. We managed to do this in one day with 5 men. The wild flowers grew well. I looked at it the next year and it looked like a Spanish style stucco house with a weed patch for a roof. Since this job was about 150 miles from our home base I have never gone back to look at it and see how it has stood the test of time.

This whole house was engineered to handle the weight of the soil and to be water proof (and drain excess water).

[Dale Wiley]

Originally posted by BigD
I agree with you entirely and engineers were involved in the design process, but the specifications were terrible. I believe I found some of the answers that I was looking for, thanks to all.

The DIY'ers doing it on their own homes is a rather scary thought.

Even with " engineering" the specs can still be disatrous. We were asked top quote some footings for a deck that was 35 feet in the air, and our footings were to be supporting a 35 foot high steel beam. The moron engineer had a standard deck footing with cone columns, poured on a 12 inc concrete base poured on native soil cut on a 8/12 slope.

I looked at the general contractor and said you have got to kidding me...he said no I think it will work.. so I handed him the print back and got in my pickup and drove away, very content and happy with myself for avoiding a company ruining job.

It if feels bad, looks bad, then it is bad.

[Paul]

A properly designed green roof should bring in about 7 to 9 lbs per sq. ft. dead load. Next comes the expected engineering for each area. Northern roofs might be designed for a 45 to 50 dead load, while southern roofing systems need only a 35 lb dead load.
The added weight needs to be added into the roof design. PLEASE DON'T THINK THAT DEAD LOADS AND LIVE LOADS ARE THE SAME!!!! Live loads are only short term weights!

There are special foam trays, rubber (EDPM) membranes, grids and soil mixes that are used to achieve weight reduction over natural soils. Drainage is a big problem with the soil design, larger plants are grown in soil mixes that incorporate foam beads and smaller plant material might have a bead layer under the planting soil. The beads used are a non water absorbing type that have a hard surface to them. To archive a level look for tenants some planting beds are placed raised on light weight plastic risers that are angled so the look is more natural.

Also involved are watering systems, mostly drip types and special fertilizer injectors.