Replies

1. 
   Kevin_AtHome | Sep 14, 2001 08:42am | #1

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   Chris: be sure the studs are properly wind braced once you remove the old T1-11. Simpson (and others) sell a metal, let in wind brace strap that you set into a saw kerf in the studs and plates. What plans do you have to treat w&d openings and how much overhang is there at eaves/rakes?? If you have the room (and the budget) use the rain screen wall (furring strips), by far the best system. If the insulation is foil faced, I have had success in simply taping the joints and corners (3M, tyvek, etc). Its role is to act as the moisture shield and minimize water vaporizing on backside of siding. Lastly, always backprime the cedar siding as well as all cut edges. Venting and/or bottom seals for the rain screen walls are also things to think about. LOL

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   Frenchy_Dampier | Sep 14, 2001 04:48pm | #2

   *Danger Will Robinson, Danger! Foam on the outside, sounds like you plan on trapping the escaped water vapor and holding it up against the house where rot will easily start! Ther are too many books on what a no-no this is as well as too many lawsuits. Do it only if he directs you to do it that way then get it in writting with your note that you recommend against it. Customer is always right, but you'd better cover your Six here.

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   CaseyR_ | Sep 15, 2001 04:39am | #3

   *If your area is covered by earthquake requirements, you might want to check on what is needed to meet code. If you add enough sheathing you should be OK. I was just reading a pamphlet on earthquake requirements for Oregon and they said that let-in bracing is usually considered inadequate for earthquake resistance.

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   Andy_W | Sep 15, 2001 06:45am | #4

   *Frenchy:I hope you are wrong, because I just built an addition with 2x4 walls, r-12, sheathing, and 1.5" styrofoam, then brick. Any water vapour coming through the wall from inside won't condense on the backside of the sheathing, because it is still on the warm side of the insulation.At least I hope so.For the relatively small amount of extra work I would space the siding off the foam with some strapping, and create an airspace to reduce the likelihood of wind-driven rain getting in and keeping the back of your siding wet.CheersAndy

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   Andy_W | Sep 15, 2001 06:48am | #5

   *Chris:forgot about your original question. In short, use tyvek tape to seal the foam ( make sure it's clean) and yes and yes.Andy

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   Frenchy_Dampier | Sep 15, 2001 12:12pm | #6

   *Andy, The problem with foam on the outside is it's a perfect vapor barrior. However fiberglas insulation isn't. Water vapor goes right through it.It also will work it's way through the 2x4 studs. Now if you put up a perfect vapor barrier on the inside, (sealed Poly film with all the edges taped) you may be able to keep it under control. Remember the main cause of rot is not the occasional soaking that you get after rain, but the steady buildup of moisture from cooking, showering, etc.

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   Chris_Munro | Sep 15, 2001 12:12pm | #7

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   A client has asked me to reside his 70's home and add rigid insulation to beef up his R.-value. The plan is to remove the old particle-board T-111 type siding, add sheathing (where there was none), add a layer of rigid foam insulation then Cedar bevel siding. Any recommendations on how best to attach the siding- nail though the foam, or add furring strips over the foam board as nailers? Would furring strips help prevent moisture build-up under the siding? How should the insulation be sealed at the edges and around openings? Should the siding be finished with sealer before hanging?
   Any thoughts would be appreciated!