That is a good idea. I've actually been meaning to look into Black Locust chips given that woods ability to not rot under ground. My current project is semi intensive so my reservation is what will happen to the weight over time. The wood will decompose and shrink in depth, requiring the addition of more. Each time you do that the weight increases. Is that a valid concern?<span></span><div>
<br></div><div>As an extensive sedum or moss cover then wood chips is a no brainer. <br><br>On Saturday, October 12, 2013, John Salmen wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="EN-CA" link="blue" vlink="purple"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I would seriously look at using ground up wood waste / wood chips. They can hold their structure for years achieving a number of green roof goals without the green initially. The end product is soil so you can look at it as a green roof in process or simply an urban composting area. Wood chips have been used in biofilters and support a diversity of life. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><u></u> <u></u></span></p><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0cm 0cm 0cm"><p class="MsoNormal">
<b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Greenbuilding [mailto:<a href="javascript:_e({}, 'cvml', 'greenbuilding-bounces@lists.bioenergylists.org');" target="_blank">greenbuilding-bounces@lists.bioenergylists.org</a>] <b>On Behalf Of </b>Gennaro Brooks-Church - Eco Brooklyn<br>
<b>Sent:</b> October-12-13 4:40 AM<br><b>To:</b> Green Building<br><b>Subject:</b> Re: [Greenbuilding] Growing Media Embodied Energy<u></u><u></u></span></p></div><p><u></u> <u></u></p><p>That's very helpful. Thanks John. I agree with your list of priorities. I would add quality of life, for all biota, especially in the city. <u></u><u></u></p>
<div><p>I'm really struggling to find a lower embodied energy light aggregate here in NYC. <u></u><u></u></p></div><div><p>It's turning out to be as easy as my other quest- to find a greener option to sheet rock. <br>
<br>On Friday, October 11, 2013, John Salmen wrote:<u></u><u></u></p><div><div><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">The ESCSI (lightweight aggregate institute put out numbers in 2012). For manufactured materials like expanded shale or other lightweight aggregates the number is same for all - 2.16MBtu/ton or 1.34 mbtu/cubic yard. Carbon dioxide is 350.5 lbs/ton 218lbs/cy.</span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Sand is about 20,000 Btu per ton and Crushed stone about 30,000 Btu/ton. </span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Those numbers don’t get it to your building site though.</span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I’m doing another green roof now (extensive type) and I’ve switched from varied sedum type mix to just a moss roof (they typically turn into a moss roof anyway and its a more desirable material in my mind). Soil mix is simpler and can be limited to local sandy soils or cement sands (different particle sizes) with some aggregate – limited organics. Less saturated weight. </span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">For me the main points of a green roof are </span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">-</span><span style="font-size:7.0pt"> </span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">To substitute a natural bulk material (soils primarily) for a manufactured sacrificial material (roofing that can withstand the elements</span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">-</span><span style="font-size:7.0pt"> </span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">To reduce concentrated peak water flows (preventing erosion, etc.)</span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">-</span><span style="font-size:7.0pt"> </span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">To potentially improve the quality of the water by isolating it from typical roof contaminants that it would normally degrade and carry away</span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Plants are secondary but they can improve water quality (and air) and moss can be extremely effective for that with a higher probability of not dying.</span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Water retention (and ultimate weight) is calculated by soil mix and holding capacity. Weight is a huge issue as it puts tremendous loads on a building that have to be provided for (can really upsize a building especially in a seismic area). </span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0cm 0cm 0cm"><p><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""></span></p>
</div></div></div></div></div></div></blockquote></div><br><br>-- <br>Gennaro Brooks-Church, Director<br>Eco Brooklyn<br>347-244-3016<br>22 2nd St, BK NY 11231<br>Sent from Mobile<br>