Soliciting comments on cabin design

[SouthernTier]

Note, I was wondering why nobody brought up the hallway before, for the reasons you mention.  The reason for that hallway is two-fold.

First, it is to provide a wall against to put the fridge and kitchen counters/upper cabinets.  Second, it is to provide a small mud room space upon entering.  A place with hooks to hang up jackets, and not have blasts of cold air go into the main areas.  Also, for the corner unit of the kitchen corner, I plan on installing under-counter access (shelves) from the *hall* side to store wet boots, hats/gloves, etc.  makes good use of under counter space that is usually not well used, at least I think so.  I suppose I could do all that without a wall, although there would still be the kitchen counter there, since I switched from a U-kitchen to an L-kitchen.  I suppose I could move the fridge to the other end of the counter.  I'll give that a try in homestyler.com and see what it looks like.

You know, that just might work...



Both the fridge door and the entry door have the handles on the wrong side, but I couldn't change that.  Might keep the cook top in the corner still, not sure.

But the fridge would definitely be closer for when I feel like having another beer - a major + 

[Don_P]

 To do it by the book, I believe a sheet needs to bear on at least 3 joists, no single spans allowed. I think the minimum width is 16".

It is hard to get rid of all hallways whether walled in or not, Sometimes they have to be, but I'm glad the hydration problem got solved 

[SouthernTier]

Don, I was looking for a quote of yours but didn't find it, but it went something to the effect of "there's a reason things are done the conventional way".  I guess there is a reason I don't see too many 22-ft wide houses here.  Not easy to lay the floor sheathing.  In the front, 22' is not a multiple of 16", so I had 12" spacing on each end.  To get the floor sheathing to meet the requirements, I had to start 16" right from the start (left), and ended up instead with the two 12" spacing on the right.  But that allows this, which should do it, although it does still have one panel spanning only two joists:



One solution I could do for the hallway would be to move the entrance door further to the front.  Then I could move the kitchen back towards the bathroom wall, and put hooks up to the right of the door when you walk in (but then no "mud room" space)

The problem with that is that the cabin will be on a sloped lot, and the entrance (unless I wanted to build a big stairway up to the porch) would have to be at the back, which is nearer ground surface.  That's why it ended up where it is.  But I suppose I can consider that more.

As for the dormer, I think about how the cabin is situated on the ground and how one would approach it and look at it.  It is not like Redoverfarm's house, where you are looking straight at the house from the roof (not gable) side:



If that were the case, a shed dormer, placed lopsided on just one side, would indeed look ugly.

However, I tried to line up screen shots of the 3D rendering in the directions one might approach the cabin on the hillside here:









This is still just sticks, not sheathing, but in general, the dormer doesn't really stick out like a sore thumb too much.  Maybe it would in the middle two views when I get some walls and roofs on there, we'll have to see.  If anything, it shows how I should think about springing for something to spruce up the concrete block foundation, maybe cultured stone or something.

Oh yes, the foundation.  That's the next topic I'll get to.

[Bob S.]

My wife would want the kitchen and dinning area swaped around so as that she was  more able to talk to people in the living room while cooking.

[trish2]

More kitchen comments:  You need counter space on both sides of the sink, (24 inches minimum in my book but others have gotten away with a bit less)   Are you having a dishwasher? If not, you need somewhere for your dishes to dry once washed, and usually that means a plastic dish drain on the counter.  Additionally, you need some counter space next to the frig. 

Regarding no oven:  Consider a microwave/kitchen vent combination mounted above the cook top.  We use to have a microwave and convection oven combination...it was smaller than a conventional oven, but larger than a small microwave...don't know if those are still made in that size. 

You might want to go to the library to check out a kitchen planning book that will give you some recommended dimensions.  Or you could probably get the same information on line. 

Just my thoughts....

[rick91351]

..........snip   First, it is to provide a wall against to put the fridge and kitchen counters/upper cabinets.  Second, it is to provide a small mud room space upon entering.  A place with hooks to hang up jackets, and not have blasts of cold air go into the main areas.  Also, for the corner unit of the kitchen corner, I plan on installing under-counter access (shelves) from the *hall* side to store wet boots, hats/gloves, etc.  makes good use of under counter space that is usually not well used, at least I think so............   snip

I vote for an 'air lock' style hallway to stop some of the cold blast from coming in. To me this is a must have in cold areas.  I like your ideas about space usage in a small area. 

You do need sit down with a kitchen planing book as trish2 writes or maybe better yet set down and talk with a kitchen designer.  Might cost you a few bucks but save a lot in the long run.  Small galley style kitchens can be extremely efficient.  Then you can have a lot of space and still be just as inefficient and cluttered.  I am sort of having to think about building some cabinets for our house now.  With what my wife has designed or laid out I think we best sit down and talk with a designer before I start cutting.            

   

[SouthernTier]

Thanks.  These are really good comments.  For the kitchen, to date I have just used some default "building blocks" that came with the various design programs I used.  What I'll have to do is measure the sink and cooktop I have (came out of our old kitchen at home when we remodeled it a few years ago), and do a real design of how things fit. 

And get a kitchen design book!

(note, no dishwasher or stove - keeping the cabin small.  However, I may look into those combination microwave/convection ovens to be able to do a little bit of baking if necessary - no turkeys or anything big, though).

Traveling for pleasure (visit son at college) and work this week.  Will post on the foundation when I get back home.

[SouthernTier]

I'll be picking up a couple kitchen design books from the library tomorrow to get some ideas.

Meanwhile, on to the foundation.  The cabin location slopes 20%, which is why I have designed a walkout basement.  But the full basement is only under half the cabin.  Picture worth a thousand words:



The red line is the existing 20% slope and the curved line is how I plan on grading the soil after the excavation.

This shows I've drawn a full basement in the front, with a stepped footer to get the required 4' frost depth at the bottom of the footer (the basement floor would be at the elevation of the footer towards the back of the full basement - the front part would be native soil for the first two feet).

I show here the back being a crawl space.  The next image shows I get the required 4' below surface for frost protection



But there is actually two things wrong with this design.

First, the height of the unbalanced fill towards the back of the full basement is ~6 feet.  Squirl has a nice summary of code requirements for block walls here.  The cabin location is on the boundary of two soil types, and the engineering properties listed for the soil run the gamut (multiple categories listed), but would put me in either the second or third category (some ML-CL, but also GC and ML).  The soil is actually pretty stout.  Although I am just at the edge of the extent reached during the Wisconsin glaciation (near the northern tip of the Salamanca reentrant for you geologists out there), the soil is definitely till so it is poorly sorted.  Although there is a lot of fine grained stuff, there is also a lot of small to medium size rocks, and some larger grained stuff.

Regardless, the code says that if I want to stack 8-inch blocks, I can't go more then 4 feet of unbalanced fill.  So the question becomes - am I truly unbalanced?  The portions of the wall just to the left of this ~6' "unbalanced" portion are in fact balanced by the wall going across the back of the full basement:



Is that enough balance?  Is the fact that it rapidly drops to 4' "unbalanced" as it gets away from the wall make a difference?  Would filling the voids and/or adding rebar in the voids make a difference?  I  suspect the answer is "ask an engineer".  But other suggested answers/guesses are welcome.  I'd really not want to go to 10" or bigger blocks.

The other thing wrong with this design is that the second footer step exceeds the maximum step height of 2'.  Plus, I figure stepped footers are just a pain to form and get right.  I plan on subbing out the excavation/footer preparation/block stacking (especially since nearby jbos333 says the local amish do a great job cheap), but I figure it will be less cheap the more complicated it gets. (this and the septic are the only things I plan to sub out.  Well maybe the staining, too at the end.  I hate painting!)

(As aside, I am not looking into poured walls because I won't be able to get a concrete truck in there - see my site layout above; the closest the truck will probably be able to make it is my to-be-installed culvert over the creek.  The footers will be tough enough - will either pour these myself after the amish set up the forms using bags and bags and bags of mix, or get some pre-mix brought in with a bobcat or some other bucket.  The only other option would be to get it pumped, but that's expensive, too I think, especially since it is somewhat uphill)

So what about this option:  Rather than double stepping the footer, schleping even more bags of mix in, etc. could the crawl just be done with a PWF?  Like this?



What I've drawn up is having a vertical "beam pocket" in the full foundation wall and putting a 6x6 beam in there for a few feet to get a solid tie-in (5.5" beam, plus the 1.5" 2x8 and 1.5' 2x6 flat pieces = 8.5" so I would have to shave about 1/2" from the 6x6 where it goes into the "beam pocket")



If this doesn't have some deal breaker that I am not aware of, I can still think of two drawbacks. 

The first is that PWFs work best in well drained soil.  My soil is not wet - water table nowhere near the surface and building site is on a spur between two reentrants.  And it is not, say, lacustrine clay.  But it is not sand either.  I would be adding lots of stone that I'd have to lug in, but they make machines for that.

Second, above I have a ridge beam with three columns.  Two of the columns would rest on the block full-height foundation.  But the third would sit on the rear wall.  I suppose that would be another bit of engineering.  What I could do there, is rather than doing the PWF framing the whole way across as I've shown here, I could  pour just an appropriate sized reinforced footer just in this one location for the column, and do the rest with the PT wood?

I really like PWF option because I can do this myself and it's easier to lug the wood in than the blocks and bags of mortar.  So I would be interested in hearing what people think.

Last point: two things are not shown here:

• The floor joists have a girder running up the middle of the crawl space part of the cabin.  That girder supports a load bearing wall above that is load bearing because it supports a similar girder onto which I've hung my loft joists.  So this floor joist girder will have intermediate supports in the crawl space.  I plan to add two supports sitting on appropriate sized footers
• Since this is a hillside, I would be putting in footer drains draining to daylight along all the footers, including the bottom of the PWF if I go with that.  The sides would also be finished according to code (surface treatments, placement of gravel for drainage, etc.

[Squirl]

First, the height of the unbalanced fill towards the back of the full basement is ~6 feet.  Squirl has a nice summary of code requirements for block walls here.  The cabin location is on the boundary of two soil types, and the engineering properties listed for the soil run the gamut (multiple categories listed), but would put me in either the second or third category (some ML-CL, but also GC and ML).  The soil is actually pretty stout.  Although I am just at the edge of the extent reached during the Wisconsin glaciation (near the northern tip of the Salamanca reentrant for you geologists out there), the soil is definitely till so it is poorly sorted.  Although there is a lot of fine grained stuff, there is also a lot of small to medium size rocks, and some larger grained stuff.

Regardless, the code says that if I want to stack 8-inch blocks, I can't go more then 4 feet of unbalanced fill.  So the question becomes - am I truly unbalanced?  The portions of the wall just to the left of this ~6' "unbalanced" portion are in fact balanced by the wall going across the back of the full basement:

Is that enough balance?  Is the fact that it rapidly drops to 4' "unbalanced" as it gets away from the wall make a difference?  Would filling the voids and/or adding rebar in the voids make a difference?  I  suspect the answer is "ask an engineer".  But other suggested answers/guesses are welcome.  I'd really not want to go to 10" or bigger blocks.[/list]

Sorry I missed this before.  You can just switch to TABLE R404.1.1(2) 8-INCH MASONRY FOUNDATION WALLS WITH REINFORCING WHERE d > 5 INCHES
http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_4_par044.htm

I have clay soils and I almost always design for them.

For 6' of unbalanced you can add #5 rebar 48" O/C.  Since #5 rebar is less common, I usually switch to #4.
Using footnote b.
b. Alternative reinforcing bar sizes and spacings having an equivalent cross-sectional area of reinforcement per lineal foot of wall shall be permitted provided the spacing of the reinforcement does not exceed 72 inches.

and

TABLE R404.1.2(9) MINIMUM SPACING FOR ALTERNATE BAR SIZE AND/OR ALTERNATE GRADE OF STEEL
http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_4_par046.htm

I would use #4 rebar at 31" O/C.

No engineer stamp required.

[SouthernTier]

Thanks Squirl.  Very helpful!

I was thinking those tables only applied to building foundations in seismic areas.  I guess they are *required* in seismic areas (i.e. no block walls without reinforcement), but they are also *suitable* for nonseismic areas where one wants >4' unbalanced fill.

I checked the soil types again and got mixed up on which two were at the cabin location (right on a seam, although those lines can't be all that precise), and which one was in the valley lower down.  I actually have Franklinville channery silt loam and Dalton silt loam.  At the depth of the footers, each of these has the soil classifications of GC-GM, GM, ML, SM.  Not sure why all four are listed.  But no clay.  This puts me in the middle column.  Doesn't seem to make much difference in the rebar requirements anyway.

I'll still need an engineers stamp since I am using a ridge beam.  And also for the insulation - no way am i going to put the default R-49 in the roof/ceiling!  Way too much!  I'll have to have the engineer sign-off on the rescheck calc.  I can probably get someone in my day-job office to stamp it for me, but the fewer things I have to him check, the easier it will be.

[Squirl]

Ridgebeam:

Speedfunk passed the engineering requirement by giving the dimensions to the contractor desk at the local building supply and they gave him back a stamped glulam and the paperwork to go with it that would pass.

If you extended it a few more inches into the room, you could get away with dimensional lumber.
TABLE R502.5(1)
40 psf 22 ft wide building - 4-2x12's - (interpolated) approximately  12'-6".

Energy code.

Use of rescheck should be able to be used without requiring the stamp. 
State code enforcement website.

http://www.dos.ny.gov/DCEA/energycode_code.html

It is also written into the code itself.

N1101.4.1 Compliance software. Compliance can be determined through the use of computer software developed by the United States Department of Energy (DOE), including REScheck, COMcheck,or REM/Rate home energy rating and REM/Design Home energy analysis software specifically developed for this code, or of other building energy modeling or home energy rating (HERS) software approved by the Secretary of State.

http://publicecodes.cyberregs.com/st/ny/st/b400v10/st_ny_st_b400v10_11_sec001.htm

[TheWire]

In regards to your single dormer looking lopsided, I put 2 dormers in my log home with a 1/2 loft.  One dormer is in the 22' cathedral ceiling of the great room and adds an interesting feature to the ceiling.

[SouthernTier]

Thanks for the input.  Those are beautiful dormers!

The one problem I can see with adding more dormers is that I am already on the bubble with regard to passing rescheck, and that is with R38 in the rafters *plus* an inch of foam board under that.  And that assumes I get R21 for the walls.  I think if I added more dormers, it just adds more surface area for heat loss, and if that surface area isn't super high R-value, then passing rescheck will be even harder.

I know this is a problem of my own making since cathedral ceilings and a lot of windows in front just isn't that energy efficient, but that's what I am interested in.

Which brings me to another question I have been meaning to ask:  My draft rescheck runs have been assuming I can get the R-38C (not R-38) insulation for the rafter and R-21 for the walls.  It's on the suppliers' websites, but I don't seem to find it for sale anywhere.  OK, I just checked homedepot and lowes online and they have it now (didn't before last time I checked), but still no 38c.  Does this stuff even really exist?  The regular R-38 won't work for me since I want to have a cold roof and need the air flow space.  That is what the "c" stuff is supposed to handle.

And thanks again Squirl for the code interpretation help.  Don't worry, I will still check my (my employer's that is) hard copy version so I won't have to take your word for it!

[SouthernTier]

Thanks guys for keeping the thread alive while I went back to the drawing board.  Took a while.

Where we left off, I was taking Don_P's advice and replacing my 3 x 9-1/4" LVLs with 2 x 11-1/4" LVLs since these also did the trick, but just were taller.  That (taller) became less of an issue when I took the advice to not notch the rafters and have them sit on the beams, but attach them to the face.  Also, I needed to go from a 10/12 to a 10.5/12 pitch in order to get enough headroom to meet code for 50% of floor space > 5' was also > 7'.  This also meant lowering the floor, forcing me to use 2x6 joints @12" oc.  So I get a stiff ridge beam but a flexy (but strong enough) loft.

And finally, the barge rafters would be supported by vertical 2x6 lookouts rather than extended top plates.  And these would just be 2x6's, not 2x12's like the real rafters.

This is what I came up with (just noticed I forgot to trim those top plate extensions - ignore those):



I also increased the slope of the porch rafters up to 4/12 and increased the size to 2x8's.  The dormer will dump onto the porch roof, which is problem discussed starting here.  So I may increase the number of rafters below the dormer from 2 to 3.  Note, the dormer spans from the ridge beam to the wall, so there is no load on the adjacent common rafters.  I haven't shown the dormer sidewall framing here.

Both the ridge beam and the rafters are 11-1/4", so there is some stickup above the beam.  I understand this is better than the other way around because the rafter is in compression rather than tension under load.  That said, it is about the same price to go to a 11-7/8" LVL or to plop a 2x4 on it's side up there.  But I will leave some space to allow the venting out the peak.

Here's the side and back view:

<<SNIP rest of that post>>

The forum software was just warning me that this thread hasn't had a response for over 120 days.  Yikes!  Will this cabin ever be built?  I hope so, been busy working to save up for it, but am getting close.

So close, I actually have some lumber for it.  I quoted the above post because this is where I went to the 6" tall joists in order for the loft to meet the code requirements that 50% of floor space > 5' was also > 7'.  Don_P agreed that the 2x6's @ 12 OC would be flexy but would work.

I later read this thread on 4x6's as joists, and that got me thinking.  According to the consensus on that posts by folks like Squirl and Don_P, using 4x's rather than 2x's allows one to double the spacing given in the span tables, and you can "claim" a 15% strength bonus as well so long as spacing is less than 24" O.C.

So I redid my design using 4x6's @24":



Which means I needed 4x6's which normally aren't available except as Pressure Treated posts (not what I'd want).

Which brings me to this huge spruce which was growing about 8 feet away (at its base) from my house:



Not only had many of those branches already fallen onto my house, but that tree actually was leaning over towards my neighbor, who is a real nice guy.



So after many years of talking about it, we finally had to take it down.  Making a long story short, I hooked up with a local miller.  I sent off two 12-foot logs from the bottom, and a 10-foot log taken from further up.  He was able to mill it into all these boards:





I only asked for the 4x6's and a couple of 6x6's (for the posts you see in the rendering above), but he provided me with all those 4x6s plus an assortment of other milled boards (foreground), including some very wide (but with wane on both edges) 12-footers stacked up against the roof in that second picture.  Five of the 4x6s also had significant wane and I was going to leave them with him, but took them figuring they'd make great posts for a woodshed I want to build once I clear trees for starting the cabin.

I was only able to get one 6x6 post due to that log coming off too high on the tree and this was the best he could do, but overall, not complaining; very happy with the product.



My design (above) only requires 15 4x6's, but I had him mill 21 in case the inspector has a problem with the native lumber (NY has a native lumber law, but I suppose it is up to the inspector to say what is OK).  21 would allow me to drop down to 18" spacing if I had to. 

The boards are of course slightly larger than the dimensional lumber to allow for shrinkage during drying.  I plan on stickering them up and drying them in my garage for up to two years for them to be ready for construction.

[SouthernTier]

Keeping up my tradition of posting on this design once every two years....

Actually, I think I may start the cabin this year.  Last college tuition check has been written so now my wife and I probably can afford it.

I probably will only get the foundation done this year.  Included in that will be the septic, and between those two items, I am probably looking at least a third of the cost, which might be all I can bite off this year.  But that means I need to finalize the foundation design.  I posted about this earlier in this post: http://countryplans.com/smf/index.php?topic=12801.msg168325#msg168325

To recap, I have a sloped lot, so will have a walkout basement, but only want to have a full height basement in the front, just a crawl in the back. The red line is existing grade, and the green line is how I will grade the soil after foundation construction to get the 48" depth to below frost line.



I want to do this for two reasons.  One is less excavation in the back (and less chance for water infiltration by not digging so deep.  Second I really want a basement wall across the middle of footprint as I need this for load bearing purposes



The problem with that design is that the uphill stepped footer is too much of a step (code limits this to 2').  Plus, the sequencing of this had me scratching my head.  I'd have to have the front part built first (I am subbing this out), then would have to build the back.  Since I want to have footer drains at the bottom of the middle wall, it would complicate the vertical part of the step there.  So maybe the rear footers need to go in later. 

But this means this complicated sequence:

• excavate and install downhill footer
• build full-height wall and install footer drains
• backfill with stone around this wall to allow drainage
• excavate uphill section
• construct uphill footer (somehow, possibly with step, and not interferring with the middle wall footer drains)
• build crawl-height wall and install footer drains
• pour concrete floors

Seems like a lot of steps to communicate to a contractor, and there are a lot of different elevations going on.  Sounds like a recipe for something to go wrong.

So I thought of this and wonder what you think.  The idea is that rather than pouring a footer for the back (uphill), why not just pour a slab.  Details below, but this would simplify the process to:

• excavate and install downhill footer
• build half of the full-height wall and install footer drains
• backfill with stone around this wall to allow drainage
• excavate uphill section
• pour the rear (uphill slab), and while they are at it, the concrete floor for the full height portion
• tell the contractor to go home and I will lay up the rest of the blocks

Not counting the last step, this is two fewer steps, and much simpler.  I was thinking either something like this:



where the slab is poured right up to the edge of the first half of the front blocks.  Of course, the footer drains would already be installed and then backfilled with compacted stone along that middle wall.  Maybe have the slab doweled into the concrete blocks.

But then I was also thinking, rather than doweling into the concrete blocks, why not try something like this:



where one fewer row of blocks is placed before pouring the slab, and the edge of the slab would be right on top of that middle wall.  I think the edge of that footer could be formed up along the wall, but not sure.

Just to be clear, when I say slab, I am thinking in terms of what the code describes as a slab on grade, for example from Figure R403.1(1) (top two images)



So I would have a turned down footing, which I believe the code requires 12 inches width around the perimeter with a height of 6 inches according to Table R403.1(3).  The bulk of the slab would just be 3.5" thick, except where I will need some support points in the middle where it would be thicker.  Plus rebar according to code, of course.

But the code is for slab *on grade* whereas this slab would be installed 4' below final grade.  This image shows where it would be with respect to the final grade (and with the blocks that would be placed on the slab):



So my questions are:

• do you think this would work?
• can I just reference the code sections for slab on grade so that I still don't need a PE stamp?

Thanks.