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Hi All<div><br></div><div>I have just seen the thread on thin shell concrete roofs , and the notion of putting up roofs first- </div><div><br></div><div>I have been doing both of these techniques since the mid 70's on and off. I nearly got chucked out of architecture school for suggesting that roofs first were a fantastic idea and used "Winnie the Pooh" as my essay reference. "We take architecture seriously - do you?"</div><div><br></div><div>I have placed my thin concrete roofs over hessian (or jute) that I can usually find second hand from carpet manufacturers. This is pinned over a pole roof structure of varying shape, a layer or two of reinforcing using one or two layers of chicken netting depending on span, and away I go with the plaster. Th addition of latex I have not tried yet but it would certainly increase the roofs resistance to cracking and leaking. Adding insulation is another tricky issue, bit I have use light weight concrete toppings (polystyrene balls) and/or internal insulation layers too. I have done spans up to 3.6 m or 12 ft</div><div><br></div><div>Great roofs - look great and easily cover such complex shapes such as a reciprocal frame roof, or where a whole bunch of roof support members are bolted to the side of a post and form a rather jagged exterior.</div><div><br></div><div>On my own house I put up the roof first (not a concrete shell in this instance) and only lost 2 hours work to the weather in a whole year, and suffered no water damage - and this was in one of those years when it felt like we were living under a waterfall. This is by far the best way to go for earth building and certainly strawbale building, especially in an unpredictable, and often wet, climate . </div><div><br></div><div>cheers</div><div><br><br><div> <span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>Graeme</div><div>Graeme North Architects</div><div>49 Matthew Road</div><div>RD1</div><div>Warkworth</div><div>tel/fax +64 (0)9 4259305</div><div> </div><div><a href="mailto:graeme@ecodesign.co.nz">graeme@ecodesign.co.nz</a></div><div>www.ecodesign.co.nz</div><br class="Apple-interchange-newline"></span> </div><br></div></body></html>