22 x 28 in Western New York's Southern Tier

[SouthernTier]

Finally starting my build thread.  The more building I do, less time to type away at this computer.  But got to start sometime, because I really want to get everybody's feedback, especially from Don_P who has been so helpful so far, and NathanS who did a fantastic NY build.  And everyone else. 

As for the design of the cabin, see the design thread link in my sig.  I have made a few updates since last posting there, but you can get the general sense.

I actually started last fall, with just the foundation and septic.  I didn't want to start my thread then because I wanted to see if I made it through the winter OK.  I was quite afraid of the foundation freezing, especially with some very cold snaps we had in January (weeks around zero F), but it made it through OK.  I bought the wall cavity insulation ahead of time and laid it on the floor to be safe, not sure if that helped or not, but couldn't hurt.

Anyway, I contracted the foundation.  It was a stepped footer and way too many blocks to lay myself working weekends (although I briefly entertained the idea). 



I wanted to keep to code without any custom engineering required, and although I could have gone with larger blocks and more reinforcement, decided to stay with a max of 4' unbalanced fill, which meant a crawl height in the back, but full height basement in the front.  There is also the center wall to divide the two sections, and to provide a robust path for the center column to transfer its load to the foundation.  I also have a girder in the back, so provided for footers for two support posts in the back:



I needed to get the floor on before winter, so hear are some floor joist framing shots.  Discussion of the joist and sheeting locations here.

Before I put the girder posts in:



racing cold and darkness (was dark by the time I got all the solid blocking in:



I got the sheeting on in the fall, but only temporarily with some screws (ran out of time).  I had to get that on to set up my winter protection scheme:



What I did was buy the steel that will eventually go on the roof.  I laid flat a bunch of sleepers (taller in the middle), laid down the steel, put a tarp over it (just to hold it down with guy wires - the steel did the water shedding), plus some concrete blocks.  Worked like a charm and kept the plywood dry.  I really would have wanted to use advantech, but decided against it due to the pesky 47-1/2" sizing.  The joists and blocking were all arranged for 48" sheeting.

Well, like I said, made it through the winter just fine, so took off the protection system, and glued and nailed the sheeting down.  That took a lot longer than I expected because I just couldn't get that damn PL400 out of the tube.  Was still pretty cold in April.  But I did finally.  I know a dancing-on-the-deck pic is de rigeur, but like most of you I'm not much of a dancer.  But I do play bass in a couple of rock bands, so I grabbed my "campfire" acoustic bass and got this (after a few tries) on the timer:



Thanks all for the advice on the nails.  I went with the 0.113" pneumatic nails, but decreased the interval to 4" on edge, 8" on face.  The air nailer saves a lot of time, but means there is a lot of research involved in making sure my nailing patterns meet code, which are written for common and box nails.  I'll be having more questions on that as time goes on.

Started getting the walls up before the leaves came out (late spring this year).  The local lumber yard only had the 1/2" zip panels.  They say they are the same price as the 7/16", but of course that means 14% more weight for me to lift.  Oh well.



My excavator guy didn't finish spreading the topsoil last fall, but came out this spring.  That guy is awesome.  While he was out there, I had him dig the holes for the supports for the deck and porch.  I used those plastic spread footers even though I know from my not-to-code shed that drilling some holes would have sufficed (I have great rocky soil -glacial till - with good bearing capacity).



The flags are the locations for the posts:



Got them in.  Was a lot of work.  Never ordered up a concrete truck before, but they came out great.  Bolts are dead-nuts on horizontally (I built a jig to hang off the walls with a plumb bob to make sure):





I am doing this pretty much solo, so I got me some wall jacks.  Those things are awesome.  Also, to keep everything to close tolerance, what I did was put the two sole plates down on the long sides and made sure all the lengths and diagonals were spot on.  I screwed them down, and then for each half wall, put some beefy hinges between the floor and sole plates, so that when I tilted up the walls, they fell exactly, and I mean exactly, in place.



So I am more or less at this point now:



As I get ready for putting up the tall front gable wall (the front is a cathedral ceiling).  I ran a bunch of wind calculations, and decided (since I am overbuilding this anyway), to use a pair of 2x8 LVLs for the central studs (since I will have a ridge beam for the catherdral ceiling in front) which means 2x8 wall for the rest of the front as well.  I will also put an LVL "shelf" behind it halfway, as Don_P has recommended on some less beefy builds.  Probably overkill, but yeah, making sure this thing stands up.  Here are the front wall parts cut up and ready for assembly (minus the LVLs):



My plan is to raise only a quarter of the wall at a time.  Actually just the two middle quarters.  That will be heavy enough.  Plus I have two helpers lined up to help me this weekend.  Then it will be off to building the loft and rear gable.

Any and all comments and suggestions.  Don't be afraid to tell me I'm screwing up.  I'd rather hear it from you all than the inspector later on!

[NathanS]

It looks great. That's no simple foundation, but fits the site perfectly. The crawlspace with slab could be a good place to put all the utilities. Then keep the basement as a workshop so you can get stuff done in the winter. You are in good shape to have everything dried in before it's cold again too. Looking forward to seeing more progress.

[NathanS]

I also just noticed the window bucks are set up for exterior foam, very nice. You'll have zero regrets there, definitely worth the added cost.

Are you planning to cover the inside of the foundation in foam board? I couldn't tell if you put foam under the slab - or if there is a vapor barrier yet.

[SouthernTier]

Yup, thanks for your advice about the thickness of the exterior foam.  I definitely would have screwed up without that advice.

I ran the rescheck program to meet code, and I really have a hybrid on the insulation.  By going with the full three inches of exterior foam, I only need to do that on the side walls.  The front wall will be 2x8's, but as is noted in my research, it is amazing how adding more fluffy stuff has very diminishing returns (in contrast to, for example, strength, which greatly increases with depth).  However, I meet code (through rescheck) with a combination of the exterior foam on the sides, just the fiberglass on the front and back, spray foam (yes, $$) in the ceiling, and also, yes, will add rigid foam to the inside of the basement.  Rescheck told me I had to do insulate the basement, and I was thinking of framing for fiberglass, but saw your helpful post to some other thread linking to an article about use of rigid foam so long as it was covered by drywall for fire retardant purposes.  So that is my plan for that.  The basement will be conditioned space for mold control, and yes, also for use as a work space.  I have some good friends that run an old house energy retrofitting business (https://begreenny.com/) and they really sold me on the benefits of spray foam for the ceiling despite the costs.  It will allow me to avoid having to build in an air channel between the insulation and the sheeting, which saves a step.

The reason I decided not to add the outside foam to the back and front (besides not needing it to pass rescheck) is because the overhang in the back is already small (I sized the roof to be exact multiples of 3-ft wide metal panels - including allowances for the extra inches for the last panel's overlap width and the raker parts) and in the front, I already have 8-inch walls, and I have a lot of windows and doors in the front.

I have been second guessed about the split level basement, and people have a point about it probably would have been a similar cost for a full basement.  However, if I was talked into that, I probably would have screwed up and not upgraded to 10-inch blocks as code would have required and then I would have been in trouble.  My plan is exactly as you describe it - crawl for utilities and the front as a workshop.  If this were to be a full time house rather than a recreational cabin, I might have done different, but I am happy with my decision.  Plus, being on the hillside, I may have invited a lot of water problems with a deeper basement in the back - but I'll never know.

I also have a quarter of the roof load (not to mention about a third of the floor load and some of the loft floor load) going to the middle of the foundation, so I that was actually my main impetus for that middle wall.  I didn't want all that on a single metal lally column.  That also supported (no pun intended) a decision to go with the two-level foundation.

I don't have foam under the slab, but they did put a vapor barrier over the stone before pouring the floors.

I haven't seen anyone doing those extensions to the windows and doors during framing, so I was a little worried that I was getting too creative, but I think it will work better rather than adding extensions later on.  It means my windows will be on the outside rather than in the middle  of the wall like yours.  Your approach is better from the potential leakage point of view.  But I think the at-the-outside approach will be easier to implement, and considering I am a weekend builder, I am going with the easier approaches so long as they don't compromise the performance.

[NathanS]

It sounds like you're on the right track to me. We hit hardpan, seasonal water table, at around 24" here... that was a big reason I did a slab. Most of our neighbors have water in their basement for part of the year... being my first time building I was very nervous about building under water.. so I skipped it. No regrets really, other than until I have a garage it would be nice to be able towork down there. And then I would have also been asking myself the same question about block thickness (8" are heavy enough), rebar reinforcement, core filling, as you. Anyway, I can completely understand your thought process.

Your plan for wall insulation sounds good to me. My two thoughts, which it sounds to me like you have already considered...

1) The surface of the sheathing in an 8" wall will be very cold without foam sheathing. More important than the interior vapor retarder, is air sealing on the interior wall. I would be careful to really seal everything up with gaskets and electrical boxes with caulking. You could consider flash+batt since the foam guys are already coming out.

2) The spray foam unventilated ceiling. I live in a colder area than you, and did not fully research hot roofs, but there is a limit to where they work.. I was under the impression where I am it is probably too cold. The surface of your roof will be warm when snow is on it... if it is above 32F you could end up with some ice damming. A lot of this concern also goes away with it not being continuously heated all winter.


Those window bucks will work great... just have to connect the window flange all the way back to the zip wall with water proofing. 6" Zip tape should take care of that. The stretch tape is really nice, you can just cut short pieces for all the corners. If you want you could also probably nail a clapboard on the head of the window buck so that it slopes outwards from the house.

[SouthernTier]

Sorry it has been a week and a half since you last post Nathan, but it has been busy.  My brother and son both came to town for a whole week to help me, and we got a lot done.  Haven't sat in front of a computer for a while!

First, I really appreciate your comments, and please keep them coming.  For the 8" wall, I would have to put full on 4+" foam insulation on the outside since (thanks to your previous comments in another thread), I understand that the outside foam has to be a minimum percentage of the R-value of the inside insulation.  That would be a lot of foam, which I don't want to do.  I will seal everything up well.  My understanding is that the R value of inside fiberglass really has diminishing returns and that going with an 8" wall is really not that different than a 6" wall, but I could be wrong.

As for the spray foam insulation on the ceiling, I will look into that again.  It is pretty cold here in the winter too (probably about the same as you). 

Where I left off on the build, I had the front gable materials cut and laid out.  I assembled the two middle quarters (the tallest quarters) before my two helpers arrived, and with their help, we got them up with wall jacks, with the jacks placed in the middle window holes.  Never could have done that without their help, since I knew I would run out of 16' 2x4 on the jacks before I got them 100% up.  That last bit is easy by pushing, though.  Here is my son working on joining them together after we got them up:



You can see the LVLs in the middle as I mentioned in an earlier post.  This is for wind load and what led me to a 2x8 wall.  Among the references I used was this wall design guide from Louisiana-Pacific:  https://lpcorp.com/media/1354/lp-solidstart-lsl-lvl-wall-framing-technical-guide-english.pdf  That guide only goes up to tributary widths of 48" but I will have more where the sliding doors and picture windows are, and with a 17'+ wall in the middle, I am right where the deflection starts to drop off, which is why I am also adding an LVL "shelf" tied into the wall behind this wall for added wind support.

I spent a huge amount of time thinking about the center column since if I ignore any tie-in effect of the loft floor (a conservative assumption but made anyway since I have two dormers which limits the tie-in effect) it could carry up to a quarter of the roof load, and part of the loft floor, for 12,000 to 14,000 pounds with the full snow load.  I figured I would certainly need at least an 8x8 at the bottom (if nothing else, to keep the force less than the compression perpendicular to the grain less than 300 psi (even though I used as little as possible wood with such an orientation).  Since this piece was so critical, I wanted to use an engineered lumber column, since 8x8 timbers aren't stocked and I just wasn't sure if I knew what to look for.  Well, it turns out the engineered lumber columns aren't stocked around here either.  While I was reading that LP guide I linked to above, it discusses the possibility of building up columns from the narrower stock LVLs.  This is something I hadn't thought of since it seemed like the advantage of LVLs was principally in the beam orientation.  However, this stock was available, and I decided to build up a 4-ply 2x8 column for the first floor and a 4-ply 2x6 column (more or less) for the second floor.  This is not a continuous column since it also supports the loft, and it was not possible (nor advised, I would think) to just bolt girders to the LVL.  That said, one of the plys goes the full length and ties everything together.

Here you can see the column, with the last loft joist sitting on the ledge between the 2x8 and 2x6 LVL stood on end.  The girder is a 2-ply 2x8 LVL - even though the wall under this girder is a load bearing wall, it has three doors going right up almost to the girder, so you could think of that as the header for those doors.  That is perhaps overkill.  The four plies were fastened together with 6-3/4 Simpson Strong Drive structural screws in accordance with their fastening schedule.



So about those loft joists.  I posted this: https://countryplans.com/smf/index.php?topic=12801.msg184944#msg184944 a couple of years ago about how for various reasons I wanted to have 4x6 joists, even though this means I may have a somewhat flexy loft floor (but it meets strength, shear, and deflection critieria a 19.2" spacing) - note that post from 2+ years ago says 24" but I shrunk it down to 19.2".  I had a huge tree cut down and had it milled into such material because you can't by non-treated wood that size.  I had the joists drying in a garage (stickered) and finally pulled them out.  Unfortunately, some were warped and I had to go with double 2x6's in for the section over the bathroom (which wasn't going to be exposed anyway).  It was great to finally cut them to size and install them.  I am going to eventually put T&G 2x6 in for the loft floor, but these pics with some wood just laying on them gives you an idea of what they will look like:





As you can see we did some interior framing.  Overall, I was really lucky to have perfect weather for when my family crew was here, but we did have rain one day, so we worked on that interior framing and some other parts cutting under tarps that day.

My brother left a day early but I wanted to take advantage of the extra hands of my son on the last day, and we managed to get all the sheathing up on the three accessible walls (the front will have to wait for the deck), except the top strip which I want to hold off until I do the rafters.  I didn't get all the blocking in for full nailing, but can do that later - I wanted to take advantage of his hands and muscles while I could.  Here's where we left it (there are more windows in the back, just not cut out yet):





Here's a shot from the scaffolding looking towards the loft.  That is all the wood I had left, and aside from a couple of 2x10's (actually left over from last fall's floor joists) and perhaps a few 2x8's (will have to see once I get the front wall blocking in), I ordered pretty much right on.  The 8-ft 2x4's on the right are for more interior walls.



Here's a shot from the same location looking back where the wood pile was.  That was filled 4' tall a few weeks ago.  Still have the sheeting for the front there, however (the rough cut boards are from my milling operation that I had used to hold down the tarp).  When that arrived I was sure I ordered too much.  I guess I didn't!



All-in-all, a fantastic week with family working hard, cooking over the fire, haveing a great time and getting lots accomplished.  Next up is the ridge beam and the rafters!

[Rys]

Love seeing all your progress! It's really coming together nicely.

[Beavers]

Those loft joists look really cool 

[seedspreader]

Nice work! I'm in NWPA (Warren County).  Glad to see a "local" build!

[SouthernTier]

2) The spray foam unventilated ceiling. I live in a colder area than you, and did not fully research hot roofs, but there is a limit to where they work.. I was under the impression where I am it is probably too cold. The surface of your roof will be warm when snow is on it... if it is above 32F you could end up with some ice damming. A lot of this concern also goes away with it not being continuously heated all winter.

Thanks for the kind words everyone.  I accept negative comments, too, if anyone sees anything gone awry.  Better to fix it now.

As for the spray foam, I do have sufficient rather depth to do both the foam and put in air channels.  Does anyone know enough about spray foam (closed cell) to know if it can be applied after installation of air channels?  Can this be done or does the spray find its way into the channels?  I haven't talked to any foam insulation contractors yet.  If that is possible, it would be the best of both worlds with a cold roof and high-R insulation, just the extra cost and work of installing the channels and venting the eaves and peak.

[NathanS]

You are really moving fast. Those 4x6 joists look great.


https://buildingscience.com/documents/insights/bsi-046-dam-ice-dam


This is a good article about ice damming in cold snowwy climates. He says once you get to 50 lb snow load you really shouldn't be doing an unventilated roof. One of the examples is an R-50 roof in Vermont with ice damming... very similar to here.

The simple calculation would be snow having an R value of 1. On a 30 degree day with 12" of snow on the roof, total assembly is R-62. If it's 70F inside, the roof deck is going to be around (70-30)*12/62+30 = 38F, so ice dams will occur.

I don't see anything wrong with vent channels, pre-made or making them out of foam.. the main thing is making sure cold air gets in at the bottom and out at the top.

Practically all the roofs around here have ice damming in the winter. I'd be sick to my stomach to see that, once the house is done that would be such an awful, expensive, thing to try to fix. I have listened to a lot of people talk about how you can basically do whatever you want, and then peel n stick the whole roof... tell that to my neighbors whose shingles are starting to peel up on a 5 year old roof.

[SouthernTier]

Thanks Nathan.  This cabin is going to be so much better than it otherwise would be thanks to yours and others' advice.  I will either put in the styrofoam channels, or else build them out of 1x2's and 1/4" plywood.  I'd trust the wood channels to be better at keeping the foam out of the channel, but will have to compare costs.  Probably the same amount of work either way.

As for coming along fast, well, that is when I take a whole week off from work and have two helpers there full time makes things go fast.  But that isn't going to happen again, at least for a while.  Got swamped back at work after a week away, and this weekend is a washout.  The good news is that my tarp system works well now that I have a temp ridge beam up there.



I was there yesterday and there was a thunderstorm of biblical proportions, and except for some water coming in from the front wall (just has my old ripped tarp hanging in front of it), things were bone dry inside.  Had to drape that blue tarp over the wall to keep out water from the top sheeting-less strip, but then things were great.

Since this tarp situation seems to be working out, I am going to focus on getting the side porch built since the rafters continue out over that.  That way when I put the rafters on, I can to the whole thing at once.

Soliciting more advice:

I need to decide on what sheathing to use on roof.  The questions I need to decide on are (1) thickness and (2) material.

Thickness:  I don't know how much help I will be getting for getting the roof sheathing up there.  I plan on hauling the sheathing up to the loft, and then sending out the "holes" where the dormers are going (except of course, for the dormers' sheets themselves).  Still, it will be a heavy lift, litterally.  Table R503.2.1.1(1) seems to indicate I could go with 1/2-inch sheathing, even without edge support with my 24" spacing, and I may have some 1/2-inch panels left over from the wall sheathing.  Nathan, I know you put 5/8" on even with 16" spacing, so I suspect the advice is go with 5/8".

Material:  I am glad I am going with the zip system for the walls as I can't imagine trying to get tyvek up there by myself.  For the roof, I am not sure.  The advantage of going with zip for the roof is that it doesn't need the tar paper, but even if I go with the vents, I think at least one row of adhesive barrier would probably be needed.  Does the zip system really obviate the need for tar paper? 

Note, I am probably going to contract out the actual installation of the steel roof, mainly for safety concerns, and secondarily to make sure it is done right (although I have had zero problems with my shed's roof, but it was much smaller).  There will probably be a delay between when I get the sheathing on and when the roofer shows up to install the roof.  With this delay maybe it makes more sense to use the zip since I don't plan on putting the tar paper on myself, again due to safety concerns.

If I don't go with zip, would plywood be a better choice than OSB if there is an interval between the sheathing and the roofing?

Does the T&G zip cause those sheets to be 47.5" like the advantech flooring?  That could be a probably with my system designed for multiples of 4'

Thanks in advance for any and all suggestions.

[NathanS]

Thickness:  I don't know how much help I will be getting for getting the roof sheathing up there.  I plan on hauling the sheathing up to the loft, and then sending out the "holes" where the dormers are going (except of course, for the dormers' sheets themselves).  Still, it will be a heavy lift, litterally.  Table R503.2.1.1(1) seems to indicate I could go with 1/2-inch sheathing, even without edge support with my 24" spacing, and I may have some 1/2-inch panels left over from the wall sheathing.  Nathan, I know you put 5/8" on even with 16" spacing, so I suspect the advice is go with 5/8".

Getting the sheathing up there was an awful job. I used C clamps as handles. I put all the sheathing on alone, instead of dormers I had one rafter bay spaced at 24" for the chimney. Slid it out with C clamps for handles, and also clamped stop blocks on the fascia so that the first course would automatically slide into position. I nailed in as much as I could from within the attic, then climbed out on top to finish it off. The T&G likely did shrink the 48" to 47.5", if that's an issue. Without T&G I think you will need to fiddle with H clips.. I really liked that for such an awkward one person job it was one less thing to worry about.

Nothing wrong with going with the lightest stuff that is rated for 24" rafters.

I found the sheathing to be a lot more work, and similarly dangerous, to installing the metal.

Material:  I am glad I am going with the zip system for the walls as I can't imagine trying to get tyvek up there by myself.  For the roof, I am not sure.  The advantage of going with zip for the roof is that it doesn't need the tar paper, but even if I go with the vents, I think at least one row of adhesive barrier would probably be needed.  Does the zip system really obviate the need for tar paper? 

I put on ice and water shield, in retrospect it was unnecessary. In my bulk order I had included it (had it on hand, and figured why not) because I thought the code required it, but I'm pretty certain it's only required for shingles.

The ice and water shield was pretty grippy, but nothing is as easy to walk on as zip - a huge advantage. Also really easy to use the tape. And if you don't get the steel on this year, you can feel confident that tape can handle a NY winter... that is not true of any other waterproofing that I know of.

If you were installing an unvented roof, I would probably say to use ice and water shield. Ice damming could put the nail holes under hydrostatic pressure which might actually leak.

Note, I am probably going to contract out the actual installation of the steel roof, mainly for safety concerns, and secondarily to make sure it is done right (although I have had zero problems with my shed's roof, but it was much smaller).  There will probably be a delay between when I get the sheathing on and when the roofer shows up to install the roof.  With this delay maybe it makes more sense to use the zip since I don't plan on putting the tar paper on myself, again due to safety concerns.

If I don't go with zip, would plywood be a better choice than OSB if there is an interval between the sheathing and the roofing?

Does the T&G zip cause those sheets to be 47.5" like the advantech flooring?  That could be a probably with my system designed for multiples of 4'

Thanks in advance for any and all suggestions.

I thought Don P said that plywood edges swell faster than OSB now. I don't think that's an issue with steel roofing though. If you are going to have roofers do the steel, consider how much you are saving buy doing the sheathing yourself. It might not be worth it.

One last thought, if you vent using furring strips on top the roof, you essentially are building a lattice, giant ladder, to crawl around on. What Mike 870 did except without the insulation. If you go that route, that would be pretty safe/comfortable in my opinion.

Always wear a harness and make sure the slack is short enough that if you fall you will not drop over the eave.

[ChugiakTinkerer]

I finally got the plywood sheathing on my roof this spring.  Like yours it has a 12:12 pitch and a loft.  I went with 1/2" plywood (technically 15/32") and had some help.  For my project I would have been better off with Advantech, the plywood has been exposed to the weather much longer than I wanted.  But it's holding up fine.  I may have saved a few bucks going with OSB but the sheets are heavier.  I built a poor-boy scaffold to facilitate the work and reduce potential falls.  I also agree 100% on wearing a harness.

[Mike 870]

I don't have too much to add here.

I did not find installing the metal roof all that difficult, just time consuming.  I would say if you hire it out, do so because you are able to make good use of your time doing other tasks, not because it's an overly difficult job. One helper is needed to help get the sheets up on the roof.

If you decide to do it yourself, screw/nail on plenty of 2x4's to walk on in smaller sections that you can then remove as you work your way across your roof installing the metal. Be careful, take your time.  And yea wear a harness, I should have done that.  I have a video on my metal roof install on my build thread.  My roof is also 12/12 but I have all that gridwork to stand on. 

[SouthernTier]

Getting the sheathing up there was an awful job. I used C clamps as handles. I put all the sheathing on alone, instead of dormers I had one rafter bay spaced at 24" for the chimney. Slid it out with C clamps for handles, and also clamped stop blocks on the fascia so that the first course would automatically slide into position. I nailed in as much as I could from within the attic, then climbed out on top to finish it off. The T&G likely did shrink the 48" to 47.5", if that's an issue. Without T&G I think you will need to fiddle with H clips.. I really liked that for such an awkward one person job it was one less thing to worry about.

Nothing wrong with going with the lightest stuff that is rated for 24" rafters.

I found the sheathing to be a lot more work, and similarly dangerous, to installing the metal.

Good advice.  I think that is some of what that "building alone" book says, although I still haven't got my hands on my own copy of that.  Your comment about the roof sheathing vs. the steel is similar to Mike 870's.  I plan on putting the sheathing on myself since as soon as I remove those tarps, I plan on getting rafters and sheathing in as quickly as possible.  It is not always possible to have outside contractors work "on demand" (unless you want to pay extra).  There would then be a delay (but not over the winter) before I get someone to put the metal on.  I always figured the metal would be harder because with the sheathing you can at least nail rows of 2x4's to it for support, but you can't do that when laying down a 16'-long piece of metal.  Also, there is a little more room for margins of error with sizing and placement with the sheathing compared to the metal.  Like I said, I did the metal (8' pieces) on my shed (8/12 pitch), and it turned out great, but I felt that was the limit of what I could do effectively.

I put on ice and water shield, in retrospect it was unnecessary. In my bulk order I had included it (had it on hand, and figured why not) because I thought the code required it, but I'm pretty certain it's only required for shingles.

The ice and water shield was pretty grippy, but nothing is as easy to walk on as zip - a huge advantage. Also really easy to use the tape. And if you don't get the steel on this year, you can feel confident that tape can handle a NY winter... that is not true of any other waterproofing that I know of.

If you were installing an unvented roof, I would probably say to use ice and water shield. Ice damming could put the nail holes under hydrostatic pressure which might actually leak.

Good advice.  I will probably go with the zip panels (still scratching my head on the thickness) and skip the ice shield with the possible exception of the change in pitch going from the roof (actually about 10.5 on 12) to the porch (4/12) where there may be some snow buildup and there is a break in the metal

One last thought, if you vent using furring strips on top the roof, you essentially are building a lattice, giant ladder, to crawl around on. What Mike 870 did except without the insulation. If you go that route, that would be pretty safe/comfortable in my opinion.

Always wear a harness and make sure the slack is short enough that if you fall you will not drop over the eave.

The vents will be below the deck, so Mike 870's technique wouldn't apply.  I have a harness lined up to borrow and a good rope.  I used to do some rock climbing back in my younger days so I am used to roping up.  I just to make sure I never get lazy and leave too much slack.  And I won't.  On a similar note, I promised myself never to make a saw cut or blow in some nails without my safety glasses.  Sometimes I can't remember where I put them down and was tempted to say "just once" but then remind myself that "just once" is all it takes.  Same will go for the harness and the rope length.

[Don_P]

I use 5/8 to give the roofing fasteners more to bite into and osb, it's flatter and I've had fewer problems with it than ply. As osb has gotten better in quality it seems the quality of ply has gone down. The titanium or Grace synthetic "tarpaper" is good stuff, I've had it exposed for as much as 6 months with no problems. If I don't have help I've leaned a 2x 10 or better up against the loft from the main floor and build a "shelf" on it up at about 4'. Screw that "mule" to the loft. Lift the sheets up onto the shelf 4 or 5 at a time then go up and pull them up to the loft. I'll stand them up between rafters poking out. With one foot on a toeboard and one on a rafter you can bend down low and grab a sheet, pull it up out of the hole swing the tip down till the lower end clears the rafters, pivot and plop it onto the rafters. Slide it along them until over your spot ant slide it down into the clips, I'll usually angle a bit and work the clips in one at a time as I slide the sheet down into place. Standing seam is no clips if you go that route. A ridge hook and ladder is the way to install metal, Just slide it along the ridge beside a sheet at a time. I wrap the hook in an old T shirt and do the same to the ladder near the bottom and work the last sheet on top of the metal.

[SouthernTier]

Thanks Don and Nathan.  Those descriptions sound like a great approach to getting the sheets up there, and will try that.  Hopefully I can get some help.

I think I will go with the 5/8", especially with the 24" spacing, probably T&G if the lumber yard has it.  I will probably put ice shield just at the edge of the non-porch side and at the slope break on the porch side.

Does anyone have any suggestions for what vent product to use at the peak?  Searching, I saw a product called Coravent (http://www.cor-a-vent.com/) but I am sure there are others.

While I still wait for my ridge beam, I am going to start working on the porch, since the porch rafters go out over that.  Supposed to be 90s all weekend, so not ideal for working, but I knew that would be coming.

Another question: Recommendations for flashing material for porch and deck boards?  I am calling the covered (and screened in) deck the "porch", and the open deck the "deck" but both will be built in accordance with code requirements for decks, and as summarized here.  Apparently aluminum isn't recommended with treated wood due to the galvanic reaction.  Or at least with some treated wood.  The lumber yard quote says the treated wood is "MCAG TREATED #2 YP".  Can I use some sort of tape for the flashing, as I can do for windows?

Actually, that reminds me of another question.  Nathan, you suggested I use the 6" zip tape between the sheathing and the extended window framing.  Is this the product you were referring to: https://www.homedepot.com/p/Huber-6-in-x-75-ft-ZIP-System-Valley-Window-Door-Flashing-Tape-5017124/206605060  ??

[NathanS]

The two vents I saw stocked in stores were either plastic or a thin foam material. I used the plastic, and was happy with how it installed. The foam stuff seemed really fragile. buildingscience shows diagrams of using rigid foam to make spacers and then a sheet to form the vent channel. I am not sure it's worth the extra work and cost.

On my balcony I glued tar paper in between the pressure treated sleepers and flashing. For some reason I thought galvanized steel couldn't touch PT, but aluminum was OK. I am not sure if I should have done that or not. 

That is the tape I was talking about. I also mentioned the stretch tape - it is worth the expense and special order. Just cut small pieces for all inside and outside corners. I would also think about flashing the entire inside of the buck as well - definitely the sill and jambs.

[Don_P]

Aluminum and treated is the no-no. I've not seen galvanized flashing with much zinc protecting the steel so don't care for that. I tried the tarpaper barrier till an engineering professor mentioned that I was probably just making a damp galvanic layer similar to a battery... so I've gone to vinyl, not loving it as it sure isn't crisp and clean bends but it is the state of my art at the moment. Copper would be the best but expensive.

 Late for this but I put a treated rim joist wherever there will be a porch or deck ledger just in case water gets behind the flashing. There is a crew working on my clients home right now, friends of Redover's in fact. They had a rough week. They were replacing a rotting cedar deck. There was no flashing at the deck ledger and it rotted the rim joist, subfloor, sole plate of the wall and the joist ends, major screw up! I've been involved in another job like that, very disheartening, thousands can turn into many thousands in a couple of hours when you are tearing off the old deck and reveal the damage.

[SouthernTier]

Thanks Don.  Wasn't familiar with the vinyl flashing.  Sure enough, that's what is available:  https://www.lowes.com/pd/Union-Corrugating-10-in-x-50-ft-Vinyl-Roll-Flashing/3359584  Something like that, right?

I recall this earlier post of yours (don't know how I would have gotten this cabin built without your advice!): https://countryplans.com/smf/index.php?topic=14783.msg192973#msg192973  which shows your recommended flashing scheme, showing flashing between the ledger and the rim joist (yes, too late to put a PT rim joist in).  In that post, you say the flashing between these two boards "can be a rubber membrane, metal, tarpaper at min."  I assume I could also put the vinyl there, too?

Nathan:  Thanks for the heads up on the zip tape.  Looks like this is the 6-inch stuff I should get:  https://www.homedepot.com/p/Huber-6-in-x-75-ft-ZIP-System-Liner-Stretch-Flashing-Tape-5017123/206605061 or maybe one of each.

[Don_P]

Yup, that's the vinyl. If you have access to a metal brake it will brake just not a crisp as metal. I've used it in both places noted on that drawing and have also used ice and water shield on the lower 3' of wall as the flash and the vinyl just for the counterflash over the ledger. The last house I ran treated 1/2" ply sheathing up 2' then osb from there on up.

[SouthernTier]

Thanks again for all the help.  Got most of the "porch" up this week, so ready for the rafters once I get the ridge beam.  Pics first:

Here is using the laser level that Nathan recommended.  Great recommendation!  Using the minivan as a tripod.



Really worked well to get the wood level considering I was working with sloping ground.

Hopefully not any fatal flaws in this, but I came up with a design that staggered the seams using treated 2x6s to build up the columns as a way to avoid having one 6x6, then a platform, then another post, etc.  Seemed to me that introduced a lot of hinge points.  A draw back of built up posts is rot between the boards so I applied a stain to those surfaces before building them up.  I think it came out really well.  The far ends of the joists are supported by a combination of a 2x6 and 2x8, although these are not nailed together.  They sit on the 2x6 and are end-nailed to the 2x8.  Each span is only 4 feet (this is because this will be screened in and I spaced the columns for common widths of screen materiaL) so this combination should be sufficient.



Today I finished the upper portions, putting 4x4s on the small shelf and spanning the top with 4x6's



In the first picture, you can see the flashing I put behind the ledger board.  I used this rubbery material, two courses since it was only 9" wide.  Haven't applied the vinyl flashing yet as I am holding off putting down the floor boards for now.  I don't have access to a metal brake, so not sure how I am going to bend that and have it stay while I apply it, but will figure something out.

[SouthernTier]

Although getting the ridge beam is the current rate limiting step in me getting and installing the roofing material, I actually still haven't decided on the sheathing yet.  I will go with the zip system, but I still am grappling with the thickness question.  I like Don's suggestion about having more bite for the nails with the 5/8", but not sure if that is as important with a metal roof compared to asphalt shingles.

Doing some research, it appears that the 1/2" is truly sufficient, if not "best" for my application.  It is APA span rated 32/16, and according to this Huber document http://www.fransyl.com/DATA/PRODUIT/PDF_en/1034_1_en~v~ZIP_System_Roof_Support_Informations.pdf it can handle up to 75 psf at an L/240 deflection, although any deflection is just into my air channel.

Additionally, Huber says that the H-clips are not required for the 1/2" panels, according this document: http://zipsystem.com/assets/user/library/Tech_Tip_-_Do_I_Need_H-Clips.pdf   That doc also has loading info and uses an L/180 deflection critierion, giving a maximum loading of 93 psf.

So right now, I am thinking of going with the half-inch. 

[SouthernTier]

Well, I got to the lumberyard, and at the last second, I said "self, don't skimp on anything", so I went with the 5/8".  Of course, it wasn't so much about skimping as it was about hauling more mass up to the roof.  But I will get it up there somehow (probably Don_P's method).

So all the roof framing material is ordered.  It will be a relief when that is up there.  Then the exterior foam and windows (close to placing that order, probably a combo of 100 and 200 series Andersens) and I will be dried in.

On to the next question.  I will definitely be incorporating the air channel into the roof.  Below that I am going with closed cell foam.  I originally spec'ed (and had my plans stamped with) 2x12 rafters in anticipation of fiberglass fluffy stuff, but now I will be doing the close cell after doing all the permutations of reschek to get my cabin to pass.

Because of the expense, I was thinking (because I have the rafter depth), to go with the last approach outlined in this article:  http://www.greenbuildingadvisor.com/blogs/dept/musings/how-build-insulated-cathedral-ceiling  except also adding in the air channel. The image from that article I am referring to is this one:

(Again, but with the air channel above)

I was talking to a friend whose business is old building retrofitting for energy efficiency (and actually used to do closed cell foam themselves before deciding to sub that out) that realistically, despite what the code says, there is diminishing returns with any insulation depth (sort of the opposite of wood strength which disproportionately increases with depth).  I could save a lot of money by limiting the closed cell to about 4" and then adding in fluffy stuff made for 2x6 walls. 

Thoughts?  Is that article on point?