The idea is a modern farmhouse based on the Big Enchilada plans and the planhelp 16X28 modifications.  I started last summer with the foundation and have been going up from there this summer.  Progress pics to follow.


The site.  I planted trees a few years ago in anticipation of building.

Last summer

Welcome jhivy, what town are you close to? I live in Tishomingo.

Looks like a good foundation!  Congrats!!

Tickhill, I'm south of Oxford in Lafayette County.

Progress this summer.

Major improvement this weekend!

Got plenty of sun by the looks of it, are you going to try any renewable energy? One thing we are blessed with in the south is sun, no wind just breeze.
Looking good, shoot me an email if I can help in any way.
Tickhill

Tickhill, I plan on harvesting rainwater for all the water needs.  The entry cost for solar is not in the budget.  I have a neighbor with a windmill that turns all the time.  Apparently those things don't take much of a breeze to operate.  Not sure how much energy that would produce, though.

It's getting nearly roofing time.  I'm thoroughly confused and need some advice from my neighbors in the humid south about roofing/insulation/ventilation.  Galvalume metal roof over cathedral ceiling.

I had planned on rafters, sheathing, felt, metal.  A local builder says purlins on top of sheathing.  Building Science says rigid foam on top of sheathing.  I had originally planned on vents between the open rafter tails, leading above a space above fiberglass batts to a ridge vent.  Building Science tells me that's one of the top 10 dumbest things I can do, that I should seal it up.

I'm very interested in making this house as energy efficient as possible, but don't want any mold, rot, etc.  Can anybody in the humid south set me straight?

Venting and insulating a roof is very climate specific. Joseph Lstiburek and his cohorts of Building Science have a lot of great information on the topic. My own opinion is that I would believe and do what Building Science says over what any local contractors may be saying. They may have moved south     

BTW, I'm one of the 10 dumbest things to do in the south; a northerner moved south doing design advice... 
     But I have read a lot of Lstiburek 's writings over the past half decade and he does seem to make a lot of sense to me.


... and I do not "get" the whole purlins on top of sheathing idea. Especially when the purlins are placed horizontally as is seen so often. To my mind that simply provides a channel for moist exterior air to pass through and condense on the underside of the metal. 

Rafters - sheathing - felt - metal or shingle roofing works too BUT the big downside is getting sufficient insulation in the rafter framed roof AND having sufficient ventilation space above the insulation. Foam on top solves that. So does having spray foam insulation sprayed on the underside of the roof sheathing. No venting needed when that is thick enough / high enough R-value.

Well, this is where I've gotta say "we've done it this way and it seems to work fine". I don't purlin on top of the sheathing and do seal the metal down to the felt with the end closure foam to keep humid air from condensing under the metal daily. The only reason I can fathom for purlin strapping is to get better purchase for the screws that hold the metal down. I use 5/8 osb for sheathing and have not had any issues with that.

For a cathedral we use air chutes (prop-R-vent) or similar in every rafter bay, all the way, from plate to ridge, leaving a small gap between each piece of chute. This provides a continuous unblocked vent channel in every bay. Then insulate. At the bottom place blocking between rafters to within ~ 2" of the roof sheathing to keep wind washing from getting into the insulation, force it up into the vent channel.

I have not had the opportunity to take one of these roofs back apart some years later, the next generation will get to go to school on me.

In heavy timber we've done several approaches. One I like is to do exposed heavy rafters, T&G decking, Layers of foam with seams offset and taped, purlins up and down the roof attached to the rafters and heavy decking to form a vent channel and nail base, sheathing, paper and then the metal or shingles... wrap and strap. You're mighty tired of crawling over the roof by the time that is done but it is a continuous seal of unbroken insulation.

I guess what I really mean is that, IMO, if you want the best insulated cathedral ceiling, go foam on the exterior. OR fill the bays with spray foam from below.  But then I prpbably spend more than necessary for more insulation than may be really necessary.  I just figure energy costs will continue to rise. And I hoper to live long enough to see that. 

I agree, the wrap and strap and SIPs roofs we've done have been like a thermos. The next best have been sprayfoam jobs. It is interesting to see even 2x12 rafters telegraphing thru the frost on cathedral sprayfoam jobs. Fiberglass has come in behind those but the initial price is hard to beat. On our own home I have vented fiberglass with 2 layers of 3/4" foam in the underside of the rafters, seams offset and taped, then a layer of 1/2" osb screwed thru the foam to the rafters and then T&G... seems to work. The neat thing about having a layer of sheathing on the underside is you can do anything with the panelling underneath. I ran it in both directions but you could go wild and do about any pattern up there. I took down a section a few years ago and didn't see any problems.

loft framing

Ridge board support.  About 23 ft above the first floor.  A bit scary at first.

Took a couple of days off work to cut and install rafters.  Trying to get it under roof before old man winter gets here.  A couple of retired neighbors who had offered their help came yesterday.  They made a difficult job a lot easier.  I don't know if I can ever repay them.

Just before sunset yesterday.  Two-thirds of the rafters up.

Lookin good, gonna get messy this weekend with warmer temps.

Reached a milestone.  Rafters complete.  Except for barge rafters.  I consider it a major accomplishment.  Blocking between them installed also.

Barge rafters complete.  Took much longer than expected.  But what hasn't so far?

  You have reached another WOW that is finished.....  Sure makes you feel good!!!

You are doing a wonderful job. Just seeing you guys really give it your all makes me feel great. Keep up the good work!

Roof sheathed!  The "chicken ladder" is the way to go on a steep roof.  The simplest ideas are often the best.

My dad built a crane to lift the sheathing.  It was a big work saver.  Thick wall conduit fit nicely over the pin on the scaffold.  Add a pulley and a boat winch.