2020 woodshed design, mark 1 is built and filled

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Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
I foresee three essay length entries here and will reserve the top posts for them.

I am very happy with my passive solar kilns. I do not like having to replace all the plastic membrane every 18 months or so. They take up a lot of space on the lawn.

A family at my church asked for my help designing and building a wood shed for them at their new house. The terrain is sloped. They have five kids at home, ages 5 to 17. Both parents are working at jobs, they both have ongoing music gigs outside of work hours, and after they spend time with the kids they don't have a lot of time to stumble on this website or build woodsheds. They anticipate burning 3-4 cords annually.

We looked at the woodshed built by the father of the bride, and we looked at the "official" local air police wood shed design. If you internet search "fairbanks wood shed" you ought to see a link to a .pdf on page one of your results. It is the one with the swanky cedar walls and floor boards. The father of the bride essentially increased all the dimensions on the official plan by 75% or so and built that.

Thing is when I or anyone else apply for a waiver from the air police to operate our solid fuel burning appliances during moderate air quality events inside the rectangle of death part of the application is to attach a photo of the shed where the fuel for the proposed waivered stove is to be stored. Since my photo didn't look like the official shed I had to go to the office with more pictures and a stick of dry firewood and find a place to park. The functionary was all very nice about it and complimented my design. I suspect my annual waiver applications will be approved until the functionary is replaced, but then I will have to drive over there, again, find a place to park, again, rant mode paused.

The trouble with the official design is floor is just barely 48" x96" and the shed is supped to hold one cord. Joe User is going to stack three rows of wood in there and I am not convinced the middle layer is going to have good enough air flow to get dry in one season. There, I said it.

Also, the official design has stacked cordwood in direct contact with the pressure treated 4x4 posts holding up the roof. I don't like it. Burning actual PT lumber is really really bad. I have not found a single peer reviewed study on seasoning cordwood while it is touching pressure treated lumber at all. My hunch is that once the pressure treated post has seasoned a couple of years the transfer of poisons from the PT post to the adjacent cordwood has to be pretty minimal. On the other hand, if you had a vial of rattlesnake venom in your house, would you store it in your pillowcase?

I did start a thread on the the subject of PT woodshed parts over on the main woodstove forum. Both begreen and bholler thought PT shed parts wasn't a problem. I specifically tagged BKVP in that thread and as of right now I haven't heard anything back from him. Knowing Chris he is checking with all the engineers he has on speed dial before he makes a peep.

So on the 2020-Mark 1, I have cordwood touching the PT posts. It is specified in the current "official plan", on page one of the .pdf they have actual cordwood in the accepted shed design touching PT posts. As life choices go I would rather have my cordwood touching a PT post than not wear a seatbelt or ride a motorcycle at all; but I don't like it.

So I made some site visits and drew up a plan. What I have should look close enough to the official design that the musician homeowners should never have to go to the air police office to explain how their woodshed works, but it should work a whale of a lot better than the official design. It is overbuilt for a "woodshed" but it is extremely user friendly - planned essay #3- and should have a 20-30 year service life, other than needing ongoing leveling.

So there is the design parameters, here is a pic Friday night, we finished filling this first of three units Saturday 06-13-2020.

20200614_173356[1].jpg
 
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Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
Flooring

So one cord of green birch is 4312 pounds. Going on down the scale of local woods, a cord of dry birch comes in at 2992 pounds, green spruce 2800, dry spruce 2240 pounds.

I used 2x6 #2 Hem-Fir for the floor framing, pressure treated rated ground contact (PTGC), and this is the first project where I have been using (n00b) beam caluclators along the way. Nominal foot print for each module is 4x8 feet.

It became evident _very_ quickly I was going to need a pair of posts in the center to transfer snow load directly to the ground and not pass it through the floor framing. My local snow load is 55 psf for residential structures. I don't know your local snow load, and I don't know how long you want your wood shed to last. I was looking to meet the 1/360 deflection limit for residential floors.

So lay out, in our mind, 4 cinderblocks. They describe a rectangle 4x8 feet. You put a 8 foot 2x6 from the BORG across the front 8 foot span, another across the back. There is your beams to hold up the cordwood. You got better sense than to locate a bunch of knots on the lower edge so you keep your horizontal shear strength.

Each beam, each of those 2x6s you got standing up there, will take half the load you pile on your finished floor. If you put 1440 pounds on there, 720 pounds on each beam- you just barely pass on deflection at 1/360. This with a permanent load. If you look at a seasonal load - green wood expected to lose a lot of weight in the next two months- you are still at the limit for deflection of the floor (@1/360) at 720# per beam. Each of those two 2x6s should deflect about 0.27 inches fully loaded, just over a quarter of an inch.

If you are willing for your woodshed floor to deflect like a residential roof, 1/240, you can load each beam to 1000 pounds, but your deflection will be 0.37 inches against an allowable 0.4 inches, and you will run out of section modulus (beam depth) before you get to 1050 pounds per beam.

Reality check: Many of my solar kilns are holding a cord of spruce each with 2x4 PTGC beams on 48" spans. Six cinderblocks under each cord. My 2x4 floor beams have conformed to however level my cinderblocks are - not bad, not NASA- with 700# on each 48 inch span.

So lets look at 2x6 (#2 Hem-Fir) on a 48 inch span. Wow... 1475 pounds per each 48" span, we got four of those, in exchange for putting six cinderblocks under it instead of just four. 1475# x 4 spans, we got 5900# (permanent) on that floor while meeting 1/360 deflection - closer to 1/720 actually - boom-shackaklacka baby!

FWIW a cord of green wet freshly cut white oak is supposed to weigh 5573 pounds. So if you put 6 cinderblocks under 2x6 floor framing with #2 structural Hem-Fir you should be good to go for the floor. And you know have the option of putting your center posts on the center cinderblocks, so the floor is carrying no snow load at all.

If you step up to 2x8 Hem-Fir and drop back to four cinderblocks - 1725# per beam, 3450# on floor. If you put six cinder blocks under a pair of 2x8s, so you got 4 spans at 48" each - 2500# each x 4 = you got an evenly loaded floor that will support 10,000 pounds.

I just don't see a reason to try to run 8 foot spans under wood shed. Yes, it is a pain in the neck to get them level. But running four foot spans instead of 8 foot spans increases the load carrying capactity by a lot, forever.

I am happy to run these again with whatever beams you want to run in other areas of the country. SYP - Southern Yellow Pine - is stronger than snot. I have no idea what woods are used in the NorthEast for PTGC.

The rest of the floor is straight forward, stringers on 16 inch centers to make a box 48.25 x 96 inches. Yes, you want the quarter inch for reasons that will become evident shortly.

Once you have the 2x6 framing on your six cinderblocks and level, lay on one sheet of plywood. I use BCX fir faced sheathing with good results. It should be flush at the ends (you did measure your diagonals, yes?) with the front and rear beams 1/8 pround of the plywood. Fasten the plywood evey six inches across each stringer, and around the perimeter. Use a scrap of 2x6 offcut as a measuring tool, Just lay one edge on your last fastener, set the next one half an inch in front of the measuring block. When you think you are done, double check you didn't leave any out.

You are done with the floor until you get the roof on, one little chore before you start stacking green wood. But under the plywood floor you got PTGC framing that should outlast the mortgage. Local to me team orange stocks PTGC, team blue does not. Also, I a still swooing over GRK (GRX?) fasteners. This in no place for drywall screws.
 
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Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
rats, edit window is closed.

Phase two, roofing.

If you look at the shed in post one, you can see I have three posts on the front, each with a cinderblock under it, and you can see one on the back at the visible corner. The other two are not clearly visble in the pic, but I got three pairs in there. Since all six of the posts bear directly on cinderblocks, I used 2 lag screws, 3/8 by 5 inches each to secure each post to one or the other of the 2x6 beams. As I explained it to the homeowner, the hardware is strictly to hold the roof down in high winds as the snow load is going straight to ground through the posts and cinder block. We just fastened the posts to the floor framing so the roof doesn't blow away.

Posts are almost never the problem in frames if you have room for your joinery at the top. I have worked through two post calculators, a 4x4 post (#2 Hem-Fir) is good for about 5000 pounds if you can keep it from buckling, I got six of those, I will start to be concerned when the weight of the roof and snow load is getting to 15000# though I should be good to 30k pounds if I can keep the posts from bowing. The rafters are going to be a problem (see below) when I have about 3700 # up there.

NB: Between the combined loads of the structure, the cordwood and the snow load we do expect the cinder blocks are going to sink into the ground, probably unevenly. We did take off the "sod" but the acumulated tree roots probably extend several feet underground. The load at each block, never mind soil loading capacity, is going to cut off circulation at some of the roots, they will dry out and decay (shrink) and the overlying cinderblock will sink some more. The finished structure is going to have to be jacked back level and shimmed probably annually for the first couple years and then occasionally after that, but the thing is a temporary thing, not a taxabale permanent addition to the property.

The roof panels selected by the homeowners have a section width around 3 feet. This was unexpected, but rather than rip one piece of metal roofing down to accomodate the 8 foot length of the shed, we found two ways to put a nine foot wide roof on a eight foot wide shed, at 55 psf snow load.

For the existing shed, Mk1, we put on a nine by six foot roof, with a 1 foot overhang in the front, at the back, and one foot out to the right. On the left, which is towards the middle of the proposed array, the roof comes just to the end of the floor with no overhang. This is a fairly simple problem in the age of java, a uniformly loaded beam overhanging one support.

First rafters, then purlins.

For rafters I used 6 foot 2x6 #2 SPF, one on each outboard pair of posts, with two rafters running front to back on the center post pair. Nominal slope is 2:12, eight inch rise, the front 4x4 posts are 96", the back posts are 88", the actual space between the posts is 48.25" remember. I birdsmouthed the rafters at 2:12, and used metal ties. I did use some 1/2" nominal plywood scrap between the two center raters as the 4x4 post is a touch wider than two 2x6s and I don't want them tipping over.

So four 2x6 beams, 72 inch span (48 inches between supports) , 4 of them at 743 pounds each (54 sqft roof x 55 psf snow load), pass. Good up to 950 pounds each acually, so I can put 800# of wood above the rafters and still handle the snow load. I think I have about 200# of wood and metal sheets and fasteners above the rafters, so the rafters should be good up to 66 psf snowload.

There is not, that I know of, an online tool to handle a evenly loaded beam overhanging both supports, like a rafter on a shed with an overhang front and back. All the folks I pinged with this problem said I have plenty of rafter and mostly poked at my purlins.

For the purlins on Mk 1 We are starting at the left flush with the end of the floor below, crossing the doubled and blocked 2x6 rafters on the center post, crossing the rafter to the right, and then overhanging one foot to the right.

Using five purlins (#2 SPF nominal 2x4) , one at the front, one at the back, three evenly spaced in the middle, I am good with expected deflection under 0.05 inches fully loaded on a permanent install. I did add blocking between each purlin over the rafters to minimize twisting of the purlins. Maximum moment (M1) is 116 foot pounds at 55psf- I think the timber screws I am using can take that. When I load the roof up to 67 psf snow - where I start to worry about the rafters - maxmum moment (M1) is up to 146 foot pounds.

Couple details.

With an earnest, invested, attentive assistant with no carpentry experience (the homeowner husband) the sensible thing to do was nail the metal onto the post tops while they were on the ground, bolt the posts to the floor beams, and install the rafters. Next we used very nice 2x4x96 Doug Fir (hand selected) across the front and back three posts to get the left-right spacing of the posts dialed in. Then we figured out which way we needed to twist the roof relative to the floor to get it square, did some grunting and got the diagonal braces in.


With a roof overhang at one end, the M1 moment is an indication of how hard the purlin is getting lifted off the rafter in the middle of the span by the snowload out on the overhang. Sort of. Ish. I have had to generate 100 ft lb torque second pass with a sizable wrench on my last three vehicles, and I feel good the fasteners I am using can handle 100 ftlb no problem. I would like to know how many foot pounds I can make with a 36" crowbar and then go wreck some timberlocks. 146ftlb on a fastener makes me nervous.

My local design guideline for residential buildings is 55psf. We haven't gotten that much snow in _years_. When we get to 35psf accumulated it makes the front page of the local newspaper, above the fold, usually in mid March. Folks with vintage homes hire otherwise unemployed meth addicts to shovel off their roofs, the rest of us do not expect accumulated snow load to increase by 50 percent in the remaining weeks of winter.

The beam overhanging both supports is a bugaboo. For the center of the three modules in this build the rafters are going to over hang the font and rear by a foot, and the roof is going to overhang the rafters by six inches at each end. The the left unit will be a mirror image of the one already built, overhanging to the left. I will mush the three of them together so the central overhang covers the gaps between modules.

For the center (tall) section I am going to use 6 purlins instead of 5 to (possibly?) drop the M1 at 55 psf snow to 96 ftlb. What I am not clear on, and can't seem to get a straight answer to, is how does having an overhang at both ends effect M1. If you know the answer, please use small words and short sentences,
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
User friendly features.

1. These are portable on a boat trailer. A bit heavy for two adults to carry around empty, but the tax man can look elsewhere. The homeowners were a bit concerned the five year old might play behind the wood shed out of sight of Mom at the kitchen window. So maybe spring 2021 we will move them.

2. Besides the the quantity two of 2x4x96 very nice Doug Fir used to locate the posts left right while framing the roof as above, I used two more pieces of 2x4x96 hand picked Doug Fir to widen the floor. Recall the PTGC 2x6 floor frame is 48.25 x96 with a full sheet of plywood on it. Adding a 2x4 to each edge takes the width from 48.25 to 51.25 inches. I used the nicest one I could find on the front to take all the boot traffic, heartwood up; and installed it a bit proud of the plywood floor. After the DF finishes shrinking, and the PTGC 2x6 behind it too, the edge of the plywood floor should still be protected from boot traffic, and not subject to much in the way of buckling pressure.

Besides floor wideners, splash guards if you like, functioning as plywood protectors, they also make room for an inch and a half air gap between the middle and outer layers of wood stacked in the shed. I inked the proposed air gaps onto the floor of the shed. If all the wood is perfectly cut at 16" length (I know, I know)the homeowner should be able to align the back stack to the outside edge of the floor, see both ink lines, stack the middle layer, still see all four ink lines, and then stack the front layer flush with the front edge of the floor and forget about it. When burn season starts they should be good to go if they have everything stacked in the sheds by June first or so.

3. Longest stack of wood is eight feet. They should never have to restack. Out back, two four foot wide stacks between posts. Out front, same. In the middle, one stack 8 feet long from end wall to end wall. Their stacks will move some after they dry below FSP, but the stacks should not collapse with a run that short.

4. Double posts at both ends of every stack. Some of my kilns I have one post at each end to hold an eight foot stack upright. After drying hundreds of cords I can do it without having to restack, but having two posts about 12" apart at each end makes it so easy.

5. I put the headers on the end and middle walls at the max safe height to stack green birch. The homeowner is 6' 4", young, and stout. They can stack green spruce in there up to the sheet metal. I was orginally expecting the back wall to be at about 68" with the front posts at 76", instead the back posts are 88" and the front posts 96".

6. As built, this shed can hold 20,044.5 sq inches of end grain stacking 16" splits. That's green birch up to the top the headers of the stack walls at the limit of the weight bearing capacity of the 2x6 floor beams. A face cord at 48 x 96 x 16 inches should show you 4608 sq inches of end grain, three of those at 16 inches long each should show you 13,824 sqin end grain for a full cord. 1.44 cords in this shed, x 3 sheds, 4.32 cords on a foot print 53 inches deep x 24 feet long. With spruce they can stack to the sheet metal roof as long as they got good airflow and go a little higher in capacity.

7. Cost. I am ~50% over budget on materials so far $300 v- ~$450. We don't know why yet. We have all the receipts. Those special screws for holding down the sheet metal roof are part of the problem. Also, I was planning to cut a 12' 2x4 in half for the two braces on the back wall and ended up needing two 8 foot 2x4s, but sticks are peanuts. Sticks and roof metal came in about right, we're still looking for the other $150. I did end up buying 10 foot 2x4 for the purlins that weren't in the orginal estimate for the eight foot roof. We spent about $600 so far, but we have 8 (beautiful) 4x4 PTGC posts in the garage on site at $11 per stick, and enough roofing ($75) to roof the second unit onsite also. Besides the PTGC floor framing and posts, and the four of 2x4x96 lovely hand selected Doug Fir as above everything else is #2 SPF 2x_ basic wood. The metal ties came in about right. I took 1 5/8 DWS out of personal stock to fasten the plywood floor down. They had a scad of cinder blocks on site when they moved in. I think I wrote for 5/16 lag screws and ended up buying 3/8" lag screws day of. Mrs. Homeowner is an accountant during the day before she makes dinner, spends time with the kids and then finally gets to open her guitar case, I am sure we'll get it figured out. So far the homeowners are pretty relaxed about the budget, they can easily see this isn't a collapsing pallet and tarp stop-gap solution, but one that will likely outlast their mortgage.

8. Mrs. Homeowner has already commented on how easy it was to stack in unit one.
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
Mk2 planning:

I have some changes in mind to try for the center section of this build. I am very open to hearing what changes you think might be a good idea. My plan is to incorporate some changes into the tall middle section of this build and then make the left unit a mirror image of the right unit.

If this works as well as I think it will I can go from 8 units in my back yard down to 5, which will free up some lawn space. Rather a lot of lawn space actually.

Thanks.
 

SpaceBus

Minister of Fire
Nov 18, 2018
7,089
Downeast Maine
While I think AK has great air quality laws and it's nice to see they are making sure the firewood can be seasoned properly, I'm glad I don't have to deal with them.
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
nice post poindexter
Thanks. It has been freeing to be working with a clean sheet of paper so to speak.

When I built mine, my cinderblocks were already in, so I chose to work with them rather than relocate them. Changing all the plastic on the kilns every year or two is adding up. Doing my whole kiln set up with fresh membrane is another $80 worth of plastic going to the landfill every 18 months.

I am going to add drip edge at least on the low edge of the roofing. I am seeing drips on the lowest purlin on the one that is built- but I need the framing out at the edge of the metal to make snow load.

My guy has his wood split in a big pile in the driveway, ready to load and already drying some. I guess it will be Autumn 2021 before I know if I have enough air flow to the middle stack for sure, but I think it will work.

The first one is filled with already seasoned spruce in the middle section, and green birch on the outside faces, not worried abotu that one.

Making the rest of the rafters tomorrow after work. Looking to assemble the tall middle section next weekend, but team blue has been stocking crap for Doug Fir 2x4 lately.
 

Woodsplitter67

Minister of Fire
Jan 19, 2017
2,465
Woolwich nj
Thanks. It has been freeing to be working with a clean sheet of paper so to speak.

When I built mine, my cinderblocks were already in, so I chose to work with them rather than relocate them. Changing all the plastic on the kilns every year or two is adding up. Doing my whole kiln set up with fresh membrane is another $80 worth of plastic going to the landfill every 18 months.

I am going to add drip edge at least on the low edge of the roofing. I am seeing drips on the lowest purlin on the one that is built- but I need the framing out at the edge of the metal to make snow load.

My guy has his wood split in a big pile in the driveway, ready to load and already drying some. I guess it will be Autumn 2021 before I know if I have enough air flow to the middle stack for sure, but I think it will work.

The first one is filled with already seasoned spruce in the middle section, and green birch on the outside faces, not worried abotu that one.

Making the rest of the rafters tomorrow after work. Looking to assemble the tall middle section next weekend, but team blue has been stocking crap for Doug Fir 2x4 lately.

have you ever thought of getting actual greenhouse plastic.... they have a variety of clear film and its made for this. The upfront cost is more but you will get 3 to 4 years out of it. I don't do kilns all the time, but if I were needing to do one year after year I would go that route.
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
I seriously appreciate the thorough explanations. It's a fascinating learning experience.
There are a few things in life I wished I had learned decades ago. How to do beam calculations is definitely in the top 5. I still don't know how to talk to 18 year old girls.
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
have you ever thought of getting actual greenhouse plastic.... they have a variety of clear film and its made for this. The upfront cost is more but you will get 3 to 4 years out of it. I don't do kilns all the time, but if I were needing to do one year after year I would go that route.

There are some clear plastics in the lower 48 not stocked local to me in Alaska. Like residents of Guam, Hawaii and Puerto Rico I am one of the people "of the asterisk" as in shipping not available to.

I was looking at corrugated polycarbonate panels but those get super super stiff in what I think of as cold weather and shatter easily, plus framing was going to be a nightmare.

There are some greenhouse films local, but they all have UV blockers in them last time I looked. I specifically want to let UV through the membrane.

I am trialing some 10 mil thick clear plastic on a few units this year. It was pricey, but it was left over from replacing the vapor barrier in the crawl space last summer. I'll know in a few months if it lasts any better than the much less expensive 6.5mil stuff I have been using. I put on all new membrane in June 2020, roughly half and half 10mil v- 6.5.

If I end up building some of thes at my place to get some lawn space back I think I could, in a pinch, staple up some plastic to the 4x4 posts to speed things along inside.
 

SpaceBus

Minister of Fire
Nov 18, 2018
7,089
Downeast Maine
There are a few things in life I wished I had learned decades ago. How to do beam calculations is definitely in the top 5. I still don't know how to talk to 18 year old girls.
Well, at least you don't need the latter skill anymore!
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
I have let this thread go. It took most of the rest of the summer (of 2020) to get all three modules built. Attached pic was 08-08-2020. The homeowners did get almost 4.5 cords crammed in there. They had splits laying in the lawn out in the weather but still drying some for the summer and had a fairly good heating season last year. The family was filling as the husband and I were building.

The main thing distinguishing this from similar builds was the extra 2x4 on each long edge to increase the floor width from 48 inches up to near 51 inches actual. This allows a 1.5 inch air space front and back on the middle layer of wood in there, assuming three layers of 16" splits. For birches and spruces it should be adequate to season in one summer. From reading here I would expect green oaks to take 2-3 years to dry down to <20% MC.

Use quartersawn Doug Fir 2x4 to widen the floor, and put the heartwood side up to stand up to boot traffic. Weaksauce SPF need not apply. For the upper Doug Fir to hold the post tops in relationship you could use flat or rift sawn DF, but this is the other place to use Doug Fir (tension). The rest of the 2x4 can be SPF or SPF(s).

These cost (Alaska prices) about $500 each to build, but no ongoing plastic usage for kiln membrane and they are built to last. Plan to relevel every year for 3-5 years and tell the tax man to suck a lemon.

I was on deck to help relevel the three units this spring, and I was looking for some 48" length log pieces (knot free) from them to rive some chair pieces from, but 'rona. I will ping the homeowners tommorrow to see how the shed is doing, if you have questions post up quick.

I did check in with them by phone in I think March 21. The roof held up fine, but we barely got to 30 psf accumulated snow load last winter against the design load of 55 psf.

I think this is a fair improvement over the basic design, the main thing is to widen the floor to get some airflow between the layers (front - middle -back) and I had to account for local snow load.

My apologies for the delay. According to my W2 I seemed to have averaged about 55 hours per week in 2020, no end in sight yet.

20200808_152208[1].jpg
 

Woodsplitter67

Minister of Fire
Jan 19, 2017
2,465
Woolwich nj
I have let this thread go. It took most of the rest of the summer (of 2020) to get all three modules built. Attached pic was 08-08-2020. The homeowners did get almost 4.5 cords crammed in there. They had splits laying in the lawn out in the weather but still drying some for the summer and had a fairly good heating season last year. The family was filling as the husband and I were building.

The main thing distinguishing this from similar builds was the extra 2x4 on each long edge to increase the floor width from 48 inches up to near 51 inches actual. This allows a 1.5 inch air space front and back on the middle layer of wood in there, assuming three layers of 16" splits. For birches and spruces it should be adequate to season in one summer. From reading here I would expect green oaks to take 2-3 years to dry down to <20% MC.

Use quartersawn Doug Fir 2x4 to widen the floor, and put the heartwood side up to stand up to boot traffic. Weaksauce SPF need not apply. For the upper Doug Fir to hold the post tops in relationship you could use flat or rift sawn DF, but this is the other place to use Doug Fir (tension). The rest of the 2x4 can be SPF or SPF(s).

These cost (Alaska prices) about $500 each to build, but no ongoing plastic usage for kiln membrane and they are built to last. Plan to relevel every year for 3-5 years and tell the tax man to suck a lemon.

I was on deck to help relevel the three units this spring, and I was looking for some 48" length log pieces (knot free) from them to rive some chair pieces from, but 'rona. I will ping the homeowners tommorrow to see how the shed is doing, if you have questions post up quick.

I did check in with them by phone in I think March 21. The roof held up fine, but we barely got to 30 psf accumulated snow load last winter against the design load of 55 psf.

I think this is a fair improvement over the basic design, the main thing is to widen the floor to get some airflow between the layers (front - middle -back) and I had to account for local snow load.

My apologies for the delay. According to my W2 I seemed to have averaged about 55 hours per week in 2020, no end in sight yet.

View attachment 284851


So did u use the 10 mill plastic on this and if so did it hold up better
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
The homeowner did not use any plastic on this wood shed.

I did use some leftover 10mil from a project at my house on my kilns and I was very dissapointed. It costs more than the thin stuff and didn't last as long as the cheap stuff.
 

clancey

Minister of Fire
Feb 26, 2021
2,392
Colorado
Should not they trim that tree to let in more air and sun into the wood shed--which is a pretty nice one..clancey
 

weatherguy

Minister of Fire
Feb 20, 2009
5,906
Central Mass
Should not they trim that tree to let in more air and sun into the wood shed--which is a pretty nice one..clancey
I was going to say the same thing, those branches cover 1/6 of the wood.
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
They could trim back that tree, and might, but don't need to to get the wood in there dry in one summer. Oak doesn't grow up here, just birch and spruce. One things we are facing is the concrete blocks at the end of the shed under the tree are sinking faster than the other concrete clocks. That should settle down over a few years. They are on enough of a slope that they have great airflow and don't need to trim the tree back for better sun exposure.

I am bumping this thread mainly to remind myself to get out my beam tables again to figure out what it would take for the roof to handle 50 psf ground snow load instead of 55 psf. 50 psf will cover most of the lower 48 except for the Sierra Nevada and the northern Appalachian mountains.

I am very pleased with how well this design works.
 

Poindexter

Minister of Fire
Jun 28, 2014
2,821
Fairbanks, Alaska
I will also look at leaving the center pair of posts out, That will increase the span of the purlins from 4' nominal to 8' nominal and probably won't work good for anyone facing any kind of snow load, but while I am fooling with it I will figure it out.
 
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