Peaceful Ambitions - 14 x 24 House

Started by Peaceful Ambition, March 20, 2017, 04:45:24 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Peaceful Ambition

Don, thanks for the info, would you recommend any different column caps which would offer good lateral support or will 4x4 cross bracing on each post be sufficient?

Also, poop, I didn't think to treat the cut ends of the post d*. I can still treat the top portions but for the bottom of the posts should I just spray something around the bottoms to seal them off or is it not a huge deal? We are really only getting precip in late fall/ winter.
You are not illiterate

Don_P

Without a welded assembly, no I can't. As one engineering professor noted, most knee braces as installed are simply something to fall out and hit you in the head when they fail. A panel spreads out the lateral load as shear over a large area and many fasteners. The light usually comes on as we build higher and heavier over those undersized foundation elements, then begin to contemplate or see what wind and shaking ground can do. This is part of why a full perimeter foundation works well and why I proposed building treated wall panels around the perimeter. It spreads out those lateral loads rather than concentrating them in the process of resisting them.


Peaceful Ambition

Ok, I'm trying to understand what exactly you mean when you say building treated wall panels around the perimeter? I'm trying to picture how that would look, do you have a link? My building experience is second to all, so sorry if this is common knowledge d*

Would  you recommend I return the column caps to save some money and just get some straps (i think they're called) instead? Bracing the posts and possibly doing a treated wall perimeter of course.. Or will my overall building still benefit from these column caps enough to make it worth it?
You are not illiterate

Don_P

What I'm proposing with where you are now... All of this is treated. Notch the girder into the post tops.  Align the outside face of the girder flush with the outside face of the post. Plumb that assembly and nail temporary diagonals on the inside from a post bottom to girder to brace that assembly for now. Build sections of wall that fit between posts, a top and bottom plate with vertical short studs @ 16" on center between plates. The studs should be placed so that 96" plywood breaks on a stud. Nail these wall sections to the posts and to the girder bottom.

Mound, rake and tamp a crown to the underfloor soil. You want a pitchers mound under there not a swimming pool. Cover this soil with 6 mil plastic after the floor is framed when you are done walking around on that level.

Frame the floor.

Sheath the perimeter with treated 1/2" plywood running horizontally from the bottom plate over the studs, top plate, girder and ~ midway onto the floor rim joist. Nail this to all framing members well, 4" on center around the edges 8" on center in the field using galvanized ring shank 8's. Do not overdrive the nails.

You now have a braced perimeter wall, the framing keeps the plywood bracing element from buckling under lateral shear loads from wind or seismic, the plywood ties all the elements together giving better connection than a column cap can. These wall panels are much stronger than trying to brace the posts with discrete poorly connected 4x4's. Many small fasteners ties the elements together and distributes load better than few large connections in wood. This has tied the posts, girder and floor into one assembly. When you sheath the walls above, that sheathing ties to the top half of the rim joist and up onto the wall studs above, firmly connecting the walls to the floor.

Master class, if you dig a perimeter trench to frost depth and fill it with gravel underneath these wall sections you have essentially constructed a permanent wood foundation, you'll find a sketch of that in chapter 4. Doing a foundation entirely that way from the beginning avoids the time and money involved in the piers, posts and girders but doing it the way described above picks the bracing back up of that method. Make sense?

Peaceful Ambition

Don, thanks for the detailed description!
It is making alot more sense now, and if I understand correctly, the reason that would be a preferable way to go is because shear loads are carried more directly to the ground no? My only question would be, absent the gravel, what is my bottom plate sitting on, just the ground? Or is it partially buried?

Also, at the hardware store today I realized I may have made a horrible mistake...
When I previously bought nails, I was referring to the simpson catalog which said the anchors HAD to be nailed with the 3.5'', .168 dia 16d commons and NOT the 3.25'' 16d sinkers, so I went with the longer and slightly thicker nails figuring they were the correct diameter (it's not like we all carry dial calipers)...back at the hardware store today though, I noticed that there was a THIRD 16d nail they carried (wtf how many of the same size can you have [chainsaw]) which was 3.5'' and thicker still (I'm guessing it was .168).

So my posts have been nailed with the smaller dia 3.5'' 16d nails, I haven't installed the through bolts yet. I'm sure the smaller diameter costs me some load but do you think its enough to where I should try and rip em all out to re-do them?

My Math says with a 60psf snow load and 15psf dead load each anchor should only be carrying about 2100 lbs out of a rated 10,000lbs of download, so I feel that I should be safe especially once the through bolts are in. Obviously it isn't ideal but have i created a real danger by using these nails? ???
You are not illiterate


azgreg

Don: That's cool, a PWF with a post backing.

PA: here's a build using a PWF. http://countryplans.com/smf/index.php?topic=10671.0


Don_P

Yes you are understanding my thoughts.
Without gravel to frost depth I wouldn't rest on the ground directly, frost heave potential, you could run metal panel into grade if you want to skirt it.

If you can post a link to your Simpson product I'll check it, manufacturer specs win but you'd be losing strength R&R'ing the connector too. From memory I think a 16 sinker is .148" dia and a common is .190... I do have the NDS tables here or you can check loads on the connections calc at awc.org

Peaceful Ambition

Well here's a long overdue update, progress as of last weekend! Finally got all these suckers shimmed and trimmed. Work is slow going as I work in fire and as fire season picks up my schedule gets more and more hectic and unpredictable.

Woot! on our way!  [cool]





Next stop is the built up beams, which I hope to have made if not even mounted by monday.

After thoughtful consideration (and discussing it with the missus) we've decided to just continue with the original plan to go with the wood pier foundation and likely add a continuous footing down the road, as cool as the perm. wood foundation sounds, if I'm gonna dig a trench to frost depth anyway I might as well just fill it with concrete afterwards similar to what OlJarhead is doing.

That being said, I do think that anything I can do to increase lateral stability is going to be a good idea, so I'll be headed to our local home improvement store tomorrow to return the Simpson Column caps Part # CCQ44SDS2.5 (which offer no rated lateral support and were frighteningly expensive) in exchange for some other ties, but I'm curious as to what more experienced builders would recommend I buy.

I'm looking at these two:

Simpson PC4Z http://www.dhcsupplies.com/store/p/5800-PC4Z-4x-Post-Cap.html which are rated at 1420 uplift, and 1120 lateral.

or

Simpson BC4 http://www.dhcsupplies.com/store/p/3367-BC4-4-x-4-Post-Cap.html which are rated at 980 uplift, 1000 lateral

or maybe even some basic T straps, I'm not sure what they would be rated for but I seem to see them on lots of projects with big beams. Either way I think i'm leaning towards the first, the PC4Z.

What do you guys recommend?
You are not illiterate

Don_P

I'd still build walls rather than trying to solve the problem with a sheet metal connector, the frost depth gravel was ideal, you can stay above grade. The lateral on those is one direction only IIRC.

Built up beams are easier if built in place rather than trying to build the entire beam and heave it into place.


Peaceful Ambition

I suppose it wouldn't hurt to at least price out what the extra lumber and gravel would cost to do a perm. wood foundation, couldn't hurt.

Good call on the beams, just gotta go pick up a nail gun so I can nail them on the posts without beating the anchors out of whack, 18 nails per column cap.

Finally got my quote back for lumber today, around 1800 for the house lumber and 1400 delivered for the 12x12 scissor trusses (almost $300 of which is delivery fees yikes!  [shocked]), although it seems the truss design the engineer went with has me building a balloon framed gable end wall instead of just having a flat truss bottom on the ends. I'm not sure why this is, tried calling him but he won't be back in until monday so I guess I'll find out then. :D
I can't see why it would affect things either way as loads on the gable end would be transferred the same direction anyway, no?

More to come!

You are not illiterate

Don_P

That's rare, a truss tech that knows what he is doing  :D. He is correct, again lateral, a horizontal break in the studs needs to be laterally supported by a floor, roof or ceiling diaphragm. He is running studs up to the ceiling unbroken which is correct, in high winds those cathedral ceiling trusses with gable truss ends open up and are laying somewhere in the yard in pics they show us.

Do not shoot the metal anchors if that is what you were thinking, you'll be picking a ricochet out of yourself.

ChugiakTinkerer

If you're worried about hammer strikes tweaking the brackets then you might consider a palm nailer.  I used one for tie-down straps as it allows you to work between joists.  The model I went with was a Hitachi.  Works great in untreated lumber, but the PT lumber is randomly much harder and that nailer did not impress with its random effectiveness in PT.  Just use a hammer and beat them back into place if they move.
My cabin build thread: Alaskan remote 16x28 1.5 story

Peaceful Ambition

Holy smokes it's been a while! Yikes! Fire season has proven to be way busier than I anticipated, but now that it's winding down I'm starting to remember what a weekend feels like and now it's time to get to work!

So whats new, well the wood was delivered (minus the trusses so far) and I've got the girders built and now the floor joists are nearly done!
Great advice on building those girders in place, that saved us a TON of headache, so thanks.

I'm starting to get an idea as to just how well I'm going to have to brace this sucker until I can go back in a year or two and add in either a continuous footing or a PWF. The floor joists are nearly done (about twice as many as in this picture below) and if I grab and REALLY shake I can get some wobble forwards and backwards, add in walls and a roof and some wind and there will definitely be some big forces pushing on these little posts.

Granted, there is 0 bracing I've done so far so I shouldn't be too suprised.
Based on what I was reading I was thinking doing an 'X' style brace with 2x4s lagged in (one on  each side of each post) on the 14' side, and possibly some pt 4x4 lagged in doing a 'Y' style bracing each direction on the long side. My shortest post is 18'' so i don't have a ton of real estate to nail to but I feel that this should add some pretty reasonable rigidity at least for the time being. For the 'X' bracing am I just bracing the posts to each other? Or am I bracing low on a post to the girder or floor?

What do you guys think? Appearance is second to strength and cost at this current time, but next year I'll have some more funds available to add in something a bit more beefy like was suggested a ways back...

Anyway, heres a (nearly) up to date picture, I'm two joists away from having the platform done before I can start putting in some subfloor to dance on!

You are not illiterate

Don_P

don't forget to block between joists over the girders  ;).


OlJarhead

Quote from: Don_P on September 24, 2017, 10:10:35 PM
don't forget to block between joists over the girders  ;).

haha I was just thinking that!

Peaceful Ambition

Alright, made some progress this last weekend, really feeling the pressure to step it up now before the weather comes, luckily I think we'll stay largely snow/rain free for at least a few more weeks. Got the blocking in, 'X' bracing, insulation, and subfloor.

We all gave a pretty good dance on it in celebration but sadly I forgot to take a pic of that.

I also started laying out the rear wall since there are no openings I figured that'd be a good way to ease into the other walls.

Should I vapor barrier the underside of the floor joists? I'm eventually just going to sheet the bottom to keep out little rodents and wasn't sure if that'd be sufficient.








Next step will be raising/bracing this wall and then working on the front wall, that sucker is going to have 3 4x6 windows and a door so I'm sure i'm going to spend quite a bit of time head scratching and cutting to make sure everything is laid out ok.
You are not illiterate

Peaceful Ambition

Alright! Wooo! Finally got all 4 walls up, nailed, plumbed, and straight!  :)




So, a few things have changed, first off, we decided not to put the 3rd large window in the front.
Also, due to my inexperience and wanting this thing to be as sturdy as possible, I decided against the 10' walls figuring that if I can slightly lower the total surface area on the windy side of the house (left side if your facing the front) it'd make me feel a bit better about everything, so 8' walls it is.

Now the concerns/questions.
The truss tech has said it will be around 1 month before I can get the trusses built due to their backlog, which made it difficult for me to try and figure out exactly how tall the end walls would need to be since I'm not sure if the trusses will have a seat cut, how deep it would be, etc (just intimidating having not done this before).
After talking to a distant friend of mine who frames for a living, he recommended that if need be, I could likely build a gable end to fit the inside of the end truss, and then switch my sheeting orientation from horizontal (on the lower portion of the building) to vertical over the hinge that would be created.
So as you can see, I have 8' butt walls.

Now here are my questions..
1. would this provide adequate strength? I know I am creating a hinge but could I realistically have a strong roof doing it that way? If not, would I simply be better off (in terms of both strength and loft headroom) building a standard rafter roof now that the walls are shorter? The inside chord of the trusses is only 8/12, so I'm thinking 12/12 rafters may give us a bit more room up top... What is going to be the best combination of strength, cost, and headroom at this point?

2. If I DID build normal rafters, do they still need to be tied across the entire building length when they are only 8' or will the loft provide adequate stiffening?

3. Everywhere I look it seems like people have differing opinions, should I sheet the walls horizontally or vertically for the best shear strength?

4.. Before I dropped to 8 foot walls, I didn't clearly think about how that would affect my placement of my loft joists.  ??? as you can see below, I can't really notch a ledger as planned because the door header is in the way. What is a better way around this? Could I simply use joist hangers or some type of hardware to attach the loft joists to the studs?



thanks everyone for your help, with any luck I'll be able to get this sucker sheeted and roofed before too long!
You are not illiterate

Don_P

We call that "ready, fire, aim"... I'll be working on another short day of that today  d*
with an 8/12 interior pitch and 6.5' of half building interior span width... 6.5x8=52" ceiling height above top plate. 14' floor span is going to take 2x10 joists. if you notch the upper top corner to flush their tops with the top of the top plate then you would have ~7' headroom finish downstairs and around 52" headroom right at the peak sloping down to nothing within 6.5'... is there any reason for a loft? Are these just storage "shelves" at either end of the cabin, say 4' deep or so. That would laterally support the hinges at either end. In that scenario I would lower both pitches. A nice one story.

Alternatively look at post #4 again. With ceiling joists atop the wall, extending beyond the wall, the launching point for the roof is wider. This translates into headroom below and above. Trussing it along those lines would provide a 12/12 interior, I believe you would get to a 7' swath of upstairs ceiling height. Worth sitting down with the truss tech again and asking about a cantilevered attic truss sitting on top of the walls with an eye towards cantilevering until a useable space upstairs appears.

He can do a portion in attic trusses and the rest in matching scissors if you desire a vaulted ceiling in part. The hinge should have more stiffening it than a sheet of ply. That can be the floor if you run the attic trusses the whole way. it can be a post from floor to ceiling at midpoint, or a horizontal "shelf" that acts as a beam stiffening that point, maybe a 14" deep lvl laying flat atop the 3 plates forming the end and well secured. To give an idea the required beam section modulus there is around 46"^3, the double 2x6 is about 15"^3, the ply is going to kick that up another couple, that's about it.

In the 2nd picture I see no foundation bracing on that axis. it would be a good idea to sheath at least the corners before loading higher. All sheathing edges should be blocked solid and the perimeter of all sheets nailed on 4" centers. Although running the sheets laying down produces a stronger wall in out of plane bending across the studs it requires twice as much blocking. So, most people stand the sheets, I believe the shear is identical either way. Your framer friend is not wrong on orientation. I did that not long ago in a remodel, there had been bugs and rot, hopefully evicted. I ran 1 row of treated ply horizontally then stood the sheets up the rest of the way, blocking between studs and nailing on 4" at all seams as we went. A joist hanger is ok on a header if it is sized for it... those headers look a bit slim, could be the pic, did you size them from the codebook table? The cantilevered rim joist is really just hanging by nails rather than bearing and delivering load to on something under it. As such it is not a bearing point for a ledger for deck or stairs. Likely the house girder is not sized for additional load from the cantilevered side, whatever is in front of that door should be thought of as freestanding on its own foundation, simply tied to the building for lateral support not vertical. ... if you laterally support the building  ;)

Peaceful Ambition

#43
Don thanks for your helpful reply!
Indeed! I suppose I got a bit ahead of myself and now I'm paying for it. the 'Y' bracing will be going on tomorrow, great suggestion with the attic trusses! I didn't even know those were a thing, I spoke with the truss tech and explained the situation, I also requested a 1 foot cantilever on each side. He was a bit concerned about me ASKING for a hinge but I assured him it'd be stiffened up nice and tight.

Here is what I've got now, I think this looks pretty dandy..if it gets a pass here I'll go ahead and approve the quote this week! Exciting!   [cool]

Layout



Trusses and end








I can't see on there where it mentions headroom, although Thats ok beacuse I really just need enough room to be able to sit up in bed, standing isn't too big of a deal.
When you mention sheathing the corners, the current  (8 foot) ply I have leaves around a 10-12 inch gap uncovered when stood vertically against the walls & rim joist right now, will I be better off just cutting a 10-12 inch strip to fit that or should I put the strip in the middle somewhere so I can have larger continuous pieces 'sandwiching' the smaller one?

Also I'm trying to imagine how the LVL would actually attach, that sounds like the best idea to me but I cant seem to visualize it very well, could you elaborate a bit?


EDIT: Also, crap, i nearly forgot about it, good eye....I DID make 3 of my window headers too small, they are paired 2x6 and the table says they should have been bigger, this obviously has me feeling quite stupid and bummed out. Should I try and cut the jack studs and add in some 2x4 underneath the headers then lower the sill? Or will the steep pitched roof keep the loadings low enough that I can realisticly not stress too much about it?
You are not illiterate

Don_P

I'd try for more headroom, if you are using fiberglass insulation the top chord needs to be furred down 6". Draw it cantilevered from 2' overhangs and I believe you'll get there. Have him drop the top chord of A1 and A4 for 2x4 lookouts.

The strip is fine, you'll need blocking between studs at the seam. I like to nail 2x blocks to the sides of the trusses, in line over the wall. Then notch the upper piece of sheathing to fit around and between the trusses, ending about 2" shy of the roof. This braces the trusses and airseals them up to the vent area for the roof insulation, keeping "wind washing" down.

since you are asking the tech to fire up the computer again for more cantilever... and since we have hinges on his mind. Ask him if he can wind model that gable wall with an lvl laying flatways atop the top plates directly inboard and attached to the gable truss.


OlJarhead

Over windows?  Uunder a load bearing wall?  If a load bearing wall I'd cut down the jack studs, remove the 2x6 and place the correct header.  I know it's a tough one but do it right today and not worry tomorrow :D

Peaceful Ambition

Yeah probably a good call OlJarhead, so gonna be spending today beefing up those headers, rather than ripping them out entirely I'm just building a smaller 2x4 header and placing underneath, this should give me enough strength equivilant (or nearly so) to a 2x10




I had him add a foot of cantilever and change the chord for some lookouts, but unfortunately he said his software isn't able to test the wind in that way.


I went ahead and placed an order for the trusses as everyone seems to be backed up right now. Unfortunately the trusses wont be done until late nov. or early dec.  :-\ Obviously I'll throw a tarp over it but I'm almost debating if I should just do some kind of SUPER simple low pitch shed roof or something until spring and just throw the trusses up then. Either way it's gonna be close with this weather! Should be exciting. Stay tuned!
You are not illiterate

OlJarhead

I tarped for the first winter though I did get some roof framing done Thanksgiving which helped.  The tarp worked for the most part though I often ran up just to make sure it was ok and get the icea and water off it until I could make sure it was secure.

Don_P

QuoteI'm just building a smaller 2x4 header and placing underneath, this should give me enough strength equivilant (or nearly so) to a 2x10
Stacking members provides the same strength as putting them side by side, it does not provide the same section as the deeper member of the space it occupies. Or, two 2x4's makes a 4x4 not a 2x8... a section modulus for bending strength of 7 vs about 11, a little over half strength.

flyingvan

Maybe I'm looking at the picture wrong but I don't see any jack studs.  Is that header addition supported by nails alone?
Find what you love and let it kill you.