Does anyone have experience installing “green roof,” or living roof?
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13 yrs living under one, but it's probably a little more than you had in mind.
We've got 2' of dirt up there, providing a big part of our passive heating/cooling system. Can't imagine my building any other way. A third house is started here.
What's your structure? Climate? You haven't filled in your profile.
PAHS Designer/Builder- Bury it!
Tom, that is one very cool house. How is the replacement house going? Do you have pic's of that?Tobias
Thankyou. Was also cheap to build, maintain.
Replacement house is started, not much in the way of pics. Long story briefly: started the house way back when in response to a major threatened zoning change, well before I had the money to build it. Been sitting unfinished, minimal progress for awhile. I think this year's the year.
Money's at hand, matter of priorities. Lost one year building a similar house for a client, who's loving living in it.
Elementary mistake I made building this place, designed to be my future furniture shop. Made it a little too comfortable. For instance, 25º outside now with a stiff breeze, 69º inside with a cold stove. Bright, cheery, and warm, without us doing anything.
Next place is very similar, but with features we didn't have money for. Here's the indoor lap pool start: PAHS Designer/Builder- Bury it!
Where's our photo gallery thread with step by step descriptions and photos of each phase?
jt8
"The unfortunate thing about this world is that good habits are so much easier to give up than bad ones." -- Somerset Maugham
Each phase of what? The next house? This is incredibly simple construction, the only sort I'd attempt. Walkout basement, without the house.PAHS Designer/Builder- Bury it!
Well, it looks like you've got the pics, so why not start a photo gallery thread. If this thing is a PAHS, that will give us a start to finish PAHS construction thread.
jt8
"The unfortunate thing about this world is that good habits are so much easier to give up than bad ones." -- Somerset Maugham
Those're scans of old prints. I've uprooted 25' trees, sprouted where the garage should be. We had a zoning scare that caused me to start the house (immediately!) without any money. The inspector's gonna be shocked when I call for a wiring inspection, trying to figure out what code applies. No framing to inspect, they don't care what I do for walls. Or roof for that matter, once the plan is approved.
If I get a crew together this year I'll do a thread. Here's the crane:PAHS Designer/Builder- Bury it!
I've got a small flat roof over the front entryway of my house in central PA. It's a suspended concrete slab. It doubles as a balcony for the second story. I I'm considering installing an extensive type green roof (only about 6" deep,) I've found lots of info, but not much on this type of installation. has your roof ever leaked? Also, is it damaging to walk on it, I would still like to use it as a balcony.
Nate, never a leak in either house, but the devil's in the details. Very different details from your situation. Click on my name, takes you to my profile (you should fill yours in), with a link to what's labelled my web site, but isn't exactly. Photos/description there of our place.
You know what happens to grass, and most green stuff, with heavy foot traffic. I'm not aware that the normally preferred sedum would fare any better. Gotta watch what you grow unless you're willing to water it. No reason not to have a nice lawn if you're willing to take care of it. I'm not.
There's a perfectly manicured lawn on top of a house in Saginaw, Mich. Think teletubbies. Nobody home when I stopped by, so no details. Pretty sure it wasn't PAHS.
Grew a nice crop of weeds here the first few years. Never occurred to me that trees would sprout also. Poor place for an 80' tulip poplar.
I walk on my roof frequently, have raised veggie beds up there. Photo attached, yes, it's really the roof. Look for the stove pipe in the background. I put down wood chips for paths, but they've decomposed now and I need to replenish. When finished, the whole roof will be raised veggie beds with raspberries in the shadier margins. I compost between the raised beds. Have one under glass now, for greens. We're partial to arugula and cilantro, don't have a store nearby. PAHS Designer/Builder- Bury it!
Tom, I checked out your site and the forum for PACCS. Definitely some interesting reading. Do you heat you home at all, or some wood, or what? Is that book by Hait pretty much required reading for info on PAHS?Tobias
As you saw, we go down to 65º, currently the house is cruising at 66º. Both satisfy the degree-day target of 65º. Warm enough for you? Perhaps not if you're not active. OTOH, we never come home to a cold house. 4166 heating/1131 cooling degree-days here.
You presumably saw the stove in the picture. We occasionally fire the wood stove for a few hours in the evening, particularly if we've had little solar gain that day. Doesn't take much to warm the house air up to 70º when you start out this warm. High mass houses have another benefit, you can run the stove wide open without overheating. Same for what would be over-glazing (and consequent over-heating) in a light-weight home.
Hait got considerably better performance than I do, for a variety of reasons. Reading the book is good. Bear in mind that only the heating/cooling system is pertinent. PAHS can look like just about anything. It was the annual heat storage concept, providing both heat and cooling, that was unusual back in 1983.
PAHS Designer/Builder- Bury it!
OK, so if my house identical to yours and had the same heating/cooling loads: I come home and find a 65degree house and want to make it 72-3. How long would it take for the woodstove/natGasfurnace/geothermal to raise the temp 7-8 degrees?
I've always liked the PAHS concept, but worried that it would create TOO large a heat sink or thermal battery. That it would be fantastic for mid 60's, but might take a lot of energy to get up to 70-75.
jt8
"The unfortunate thing about this world is that good habits are so much easier to give up than bad ones." -- Somerset Maugham
Think of it this way... your neighborhood is 65º outside, at its coldest (zero heating degree-days). Also inside, since you haven't been running any heat in the middle of winter. How long would it take to warm up? How much heat would it take to maintain your comfort at your chosen inside temp?
Our steel woodstove is the slow part. Once it's warmed up, the rest goes quickly.
Heating can be about anything. This time of year our house is cruising at 66º, without us doing anything. It'll drop a degree in the next 6 weeks. Add some solar, or wood, or oil, or CHP if you're generating.
The similar client house here uses an air source heat pump, which is electric resistance on a day like today. They've never seen a $100 elec bill ($50-60 is normal) for a total elec house (26k cu ft) including well pump. They're strong believers in creature comfort, love their whirlpool spa. Turns out their peak AC cost is the same as my running a dehumidifier: $1/day.
His commute time is never less than 3hrs/day. He's nuts. Should move, according to my standards. They like the house. His last one was post&beam sips, he's not going back.
Both of us would get distinctly better performance if we bothered with window coverings. About 30% of floor sq ft in glazing (over-glazed). One faces south, the other southwest. No overhangs, no over-heating. And no maintenance.
PAHS Designer/Builder- Bury it!
Give no credence to VaTom's cost estimates. He conned me into going for a green roof on my proposed 1200 sq ft shop building. He claimed it would cost only a little more to go for a green roof. Unfortunately, his relationship to a dollar appears to be a bit different from mine - the "little more" turned out to be an increase from $13000 to $20,000 to be able to hold the load of 4" of green roof growing medium.
(OK, this is for a steel framed building that was originally spec'ed to have a flimsy corregated tin roof...)
If you are interested in a green roof, you might want to consider reading the following book. It concentrates pretty exclusively on recommended green roof plants:
View Image
http://www.amazon.com/Green-Roof-Plants-Resource-Planting/dp/0881927872
Give no credence to VaTom's cost estimates. He conned me into going for a green roof on my proposed 1200 sq ft shop building. He claimed it would cost only a little more to go for a green roof. Unfortunately, his relationship to a dollar appears to be a bit different from mine - the "little more" turned out to be an increase from $13000 to $20,000
Casey, is this supposed to be a bad joke without emoticons? Or is English not your first language?
Major difference between "would" and "could". I spent nothing like that on a structural roof with 40' spans now supporting 300 tons, considerably more than your dinky 4". Clearly you also could spend 100x that. Pretty hard for me to take responsibility for stupid decisions made by others.
What I suggest is to examine all options. If one doesn't work for you, your responsibility is to choose another. If a light-weight steel building is what you deemed best for your application, why are you grousing now?
You don't know how to get a more substantial building constructed inexpensively? Take the time to read what Nate did. Costs are discussed. I clearly could have spent several times what I did, if I was dumb enough to do so.
Has nothing to do with "his relationship to a dollar appears to be a bit different from mine". Get a grip, you've lost it.
PAHS Designer/Builder- Bury it!
Yeah, my first language is COBOL...I realized I should have used an emoticon, but I find them a bit affected, so figured that the joshing was transparent. Apparently not the case. The point really was that there is possibly some extra expense required to engineer a structure for a green roof. This is particularly true if the other alternative is a prescriptive method stick built house with no green roof. To engineer a 20'x30' artist studio with ICF and a green roof cost me about $3000 in engineering fees. I assume a standard plan would have been far less expensive. (Unfortunately, the zoning of my property has changed since I started this project and I can no longer build the artist studio - so I have a set of engineered plans that I would be willing to sell pretty cheap...)There are a range of weights for growing media for green roof plants. I went with about 20 lbs/sq ft for 4" of saturated media plus about 5 lbs/sq ft for the various drainage mats, root barriers, membranes, and other material needed to prepare the roof. In my area, the required snow load calculation for the roof is 25 lb/sq ft, so with 25 more lbs/sq ft for the roof, this puts me at 50 lbs/sq ft, or about the same as the snow load for roofs in the upstate New York area. (If I had thought of it in time, perhaps I could have just bought some stock plans from Rocheter, NY.) With the zoning changes, I have to resubmit my plans. I am now proposing the shop building and a house with a wood shop and garage underneath (all that is now allowed). Both of these will have green roofs, but the I am planning on a deeper green roof on the house of perhaps up to 8" of growing media. The house will use the ICF type construction (Faswall ICF) that I had planned for the artist studio and will use LiteDeck forms for a poured concrete roof under the green roof. I have been a great fan of green roofs since I first heard about them. However, while I had planned on a green roof on my main house, I wouldn't have thought of using a green roof for my shop building until you said I should in a post a couple of years ago. I hope to post progress reports on how the shop building and the house with their green roofs when I get started; hopefully later this year.
Oops. Thank you. I had remembered that $20k figure from our first conversation.
But somebody charged you $3k to read a barjoist chart? Boy, am I in the wrong business. Takes me 10 minutes and that's 'cause I do it so rarely that I have to reread the instructions every time. $3k would about buy all my material for that small roof.
Engineering fees can be substantial. Anymore, all I need for my plan approver is a barjoist chart so she can check my reading of it. The steel company specifies how it's all connected. Our local PEs aren't happy, but paying them to read a barjoist chart doesn't make a lot of sense. And yes, I once did pay one to do that, but it was only $150. Still a waste of money.
Is LiteDeck cheaper than steel topped with a thin concrete pad? Or perhaps the height of barjoists is an issue.
I've been using 300 psf total load, heading higher on the next place. Just doesn't cost that much more (%).
Upstate NY is only 50 psf live load? Hard to imagine. That's what we use here. Sounded reasonable to me, particularly when you intend to walk around up there occasionally.
If you wanna have some fun, peruse this page: http://www.hfoesch.com/pod.html Near here and I know some history of the place, several of the leading actors, and the PE (same one who read my barjoist chart for $150).
The guy who sent me the link (who's thinking PAHS for his retirement home) had no idea he was looking at a tire house as they only made vague reference to earthships. The PE was brought in when the roof had structural problems. Pretty sure this place was completed something well north of $250/sq ft (extremely expensive here at the time). Folks who started it came here claiming they could show anyone how to build one for $30/sq ft turnkey, if you'd pay for their consultation. New owner (click on his name) needed very deep pockets to finish it, as did the one other sap who bought their pitch.
Good luck with your place.
PAHS Designer/Builder- Bury it!
Part of the reason for the high cost (the standard fee would have been around $1K less) was my obsession with making sure that the structure is as fire resistant as possible. My area in the Columbia Gorge is periodically swept by wildfires and I want something that will be nearly intact when the next wind driven brush fire rips through the area. The other factor is keeping the height as low as possible. The zoning allows for up to 35' for a residence but when I proposed a roof height of 27' for the downslope side of my house, a rather overzealous employee of the scenic area oversight agency threated to sue me over the height. An advantage of Lite Deck is that it allows a clear span roof or floor with a total roof or floor thickness of 12". It also provides a claimed R value of around R30 within that thickness. The house that I am now proposing will be built on a grade that will gives about a 7' rise in the 25' width of the house, so it will be a daylight basement for the woodshop (as I mentioned earlier). I am hoping to have the distance from the ground on the daylight basement side of the house to the roof surface on that side to be about 21'. The shed style roof will then slope up another 4' or so to the other, uphill side of the house. I will also berm some dirt against the downhill wall of the house to make that wall appear even less than the 21'. However, there will be a two car garage door on that side. I don't have the pricing for the Lite-Deck but I assume it is more than the system you use. However, I am hoping that it will cost less than legal fees that might result from a taller structure. On the snow load for upstate NY, I did just a quick google and came up with 50 to 60 lbs/sq ft for the places I could find info on. I don't know if these were the major areas. I also don't know if there are other factors in roof loading in other areas besides static load and snow load. Having helped start the environmental studies program at UC Berkeley (Conservation of Natural Resources Program), I thought I was accustomed to dealing with environmental folks. Trying to get a site plan approved for a house in the Columbia Gorge has been a whole 'nother experience, however. The process here is tilted toward factory built housing. You could put the cheapest fire trap of a factory house on the place with minimal hassle. However, anything reasonably well built that isn't an agricultural building requires an engineer's wet stamp. At $95/hr, it doesn't take long for an engineer to run up a couple of $K.
Green roof now big in Tokyo, since it's an ordinance.
Structure must be beefy, and if you can't do that due
to retrofit, etc., you can opt for lightweight greening.
Various techniques for this. The coolest (and lightest)
product I've seen uses green moss that grows in special
foam tiles, which look like stone. This you could probably
use with an existing flat roof on a wood frame building.
40 year old Norwegian log homes with living roofs in Warren VT.
Edited 2/8/2008 1:02 am ET by Riversong
I would offer the following as a starting point/resource.
http://www.greenroofs.com , gives an overview of the international efforts and resources.
Obviously the others on here are already throwing out a lot of great ideas and experiences.
ciao, ted