Replies

1. 
   wjrobinson | Jan 25, 2011 08:27pm | #1

   OSB must fall apart faster than you can say aj in your climate. There must be thousands of homes going up around you. Stop and talk to as many as it takes to find a system that you should emulate. I have learned so much from actual onsite visits of what to and not to do.

   For starters, OSB is a low end product and Hardi board is a higher end product at least where I build. Closed cell spray foam is not a least cost option, foams may work great where you are so they may have a very good value but I wouldn't say bang for you buck value.

   Anyone down there using Zip system sheathings? If it were me I would almost go to the blue wood material for framing. Frame the whole thing with borate treated products or use concrete. Concrete gives you thermal mass and is able to deal with critters well. Don't you have a big critter problem? Or does everyone just get out the pesticides monthly?

   Check out Huber products, and blu wall framing goodies.

   http://huberwood.com/

   http://www.bluwood.com/

2. 
   rockinroger | Jan 25, 2011 08:44pm | #2

   There are almost no homes going up around here . I'm considering 1" spray & batts because existing studs are true 4" 100yr. old heart pine. They laugh at nail guns.Thanks for the "zip" tip, I'll check it out.
   Ideally, if I was building new, I'd use concrete, metal studs,& Hardi due to termites. Yeah, they're using osb & Hardi 'round here. Thanks again.

3. 
   Chris K | Jan 25, 2011 08:56pm | #3

   I think Hardy can be a good choice in your climate.
   I built a timber framed house in Poplarville MS a few years ago and at that time they were just about giving away cypress blow down from Katrina. Might look in to that for siding or sheathing if there's any left. OSB can work but it has to stay absolutely dry. You live in a cooling climate so your dew point is often outside the wall. Look to for proper wall constructions.
   Be sure to use a termite shield..

   Chris Koehn

4. 
   user-928793 | Jan 25, 2011 09:24pm | #4

   Think about a Mooney wall. It's 2x2's @ 24" O.C. nailed horizontally across the studs. It will reduce your thermal bridging and increase your insulation cavity. Use blown in dense-pack cellulose; lest costly than spray foam and less prone to installation errors. Read up on the Airtight Drywall Approach or use ZIP system if you can afford it. Air infiltration can account for more energy usage than windows losses/gains.

5. GBA Editor
   Martin Holladay | Jan 26, 2011 04:51am | #5

   Roger,
   In your climate, the vapor drive is usually from the hot, humid, exterior toward the cool, dry interior -- assuming your home will have air conditioning.

   In a climate like yours, rigid foam sheathing makes a lot of sense. If I were you, I would install 1 or 2 inches of foil-faced rigid polyisocyanurate on the exterior of your sheathing, followed by vertical strapping to create a rainscreen, and then your siding.

   Spray foam is expensive. I would fill your stud bays with dense-packed cellulose or blown-in fiberglass insulation.

6. 
   Chris K | Jan 26, 2011 10:23pm | #6

   My answer above (3) should have had a link to the Building Science Corp website, and their book "Builder's Guide to Hot/Humid climates".
   Sorry for the omission.
   http://www.buildingsciencepress.com/Builders-Guide-to-HotHumid-Climates-P2.aspx