[Cob] Replacing Siding

[Frank Hanlan]

Hi Stephen,I don't think that this is a good idea for several reasons. I am assuming that by "1. Add a new layer of insulation around the entire house over the old panel siding." you mean rigid insulation board of some type. If you seal the joints with tape then you have created a vapor barrier which means moisture migrating from the inside could be trapped next to the exterior sheathing and/or panel siding resulting in mold and rot. Also if you don't do a very good job of sealing the rigid insulation then rain could be driven from the outside (winds gusting to 80 mph) which again could cause rot and mold. Also you need to be careful flashing and sealing around window and door openings. Lastly with wind gusts to 80 mph and noises coming from your house I assume that your house must be moving or flexing which could easily crack your cob.An alternative which is also not necessarily cheap or easy but might be more effective is to build an outside non-structural wall by either applying Larsen trusses or building one out of 2x3s or 2x4s 24" or 48" on center (oc) and supporting it from the bottom and/or hanging it from the eaves. The advantages of these two methods is that you can build the outside wall from 12" to 18" wide, fill it with cellulose (much less energy input to creating it) and cut down heat transfer through wood on wood from the inside out or the outside in.  You can build the Larsen trusses in the winter prior to using them in the spring, summer and/or fall but they require more work than building another exterior wall. Also you normally match Larsen trusses to the studs on your inside wall so if your inside wall is 16" on center (oc) then you usually put your Larsen trusses 16" oc which takes a fair amount of work.  You can support either wall by I-beam or floor truss cutoffs and/or hang it from your eaves.You also have an opportunity to add insulation to your attic space. If you don't have enough space you can cutoff your existing eaves, wrap poly, Typar or Tyvek over your existing roof although it may be better to remove your asphalt shingles and then build up your roof with criss-crossed 2x8s and fill in the cavities with Roxul which if more fire and mold resistant that either fiberglass or cellulose.Sincerely yours,Frank HanlanEdmonton, ABIf you have not demonstrated that you can hear the true state of the world and still act then don't expect to be told the truth.  Despite of the agreement in Cancun, Mexico we have still a great amount of work to do to ensure that global greenhouse emissions have peaked and started down by the end of 2015 and to keep the average temperature rise under 2C to stopwidespread flooding and the displacement of 400 to 500 million people.Message: 1Date: Thu, 10 Feb 2011 03:12:36 +0700From: Stephen Karrington <Sales at diamondcard.us>Subject: [Cob] Replacing SidingTo: coblist at deatech.comMessage-ID: <4D52F534.4020701 at diamondcard.us>Content-Type: text/plain; charset=ISO-8859-1Hello,I need to replace the old panel siding on a home. I was thinking aboutthis possibility.1. Add a new layer of insulation around the entire house over the oldpanel siding.2. Tack on a firm metal meshing on top of the insulation board.3. Mud directly on top of the metal mesh which should hold the mud inplace.Any comments on this plan or suggestions on what I can do? The idea isto put another layer of insulation around the house since now would bethe time. It can't hurt. And what goes on top of that should be fairlystrong and sturdy as the winds can gust 80 MPH or more sometimes downthe foothills and the house makes all sorts of noises when that happens.The house is in Colorado where its pretty cold in winter and hot in summer.An alternative is to use fiber cement boards. The cost for that is about$18-$20k according to one estimate. Which I think is expensive.Thanks.S