Stretching the 20x30 1 1/2 story ....

UperJoe · January 28, 2013, 02:14:50 PM

I am nearing the "finally" stage ...... kinda that is

I am planning on ordering the plans and stretching to 38'' and seems easy enough to do.
I also think we would be much happier going 24' to 26' vs 20' but I somewhat understand that mean lots of plan mods to allow this to be done. (?)
I will use trusses and plan on a sticking with the plans for this except for the additional length of course which will allow a bit more above.

What are the major tweaks involved to accomodate this extra width? mainly foundation or

I would hope the engineered trusses address the top issues.

Thanks for any and all feedback you can provide. Hoping to avoid having to get an architect involved if possible. $$$$ factors in at some point!

Don_P · January 28, 2013, 06:21:52 PM

Floor spans get longer than typical dimensional lumber will span. If you want to clear span floors 24 to 26' it can be done with engineered products otherwise there is typically a center bearing girder under the main floor and often a load bearing wall up through the building.

January 28, 2013, 07:13:39 PM

Thanks for some quick feedback Don

....really appreciate it! No doubt this forum will find me asking a fair amount of questions going forward - really impressed with all that is being done here and the incredible wealth of knowledge and support you and others show. It means MOUNTAINS of help to so many of us. And we owe MOUNTAINS of kuddos to you and all who save our butts time and time again.

I imagine (guessing more like it!) it boils down to cost then more so than anything. (?)
I know anything engineered comes with a price tag on it.
Maybe I need to get the plans, work up material costs both ways and decide if the value is there I suspect eh.
That extra 4'- 6' would allow alot of different layouts, at least on graph paper to happen.

I have no clue as to what a full basement may cost but that also could possibly be a solution. Even if I just stretched it to say 36' x 20' but had 720 s/f down under plus that loft maybe I could flip some things around.

My goal is to keep the build managable for me, subbing out as little as I can but not making myself go crazy (time wise) nor broke (which a basement may do). Really desire a no mortgage deal going forward as many do. Its manageable for us IF I do not get to goofy in this deal.

MountainDon · January 28, 2013, 08:00:25 PM

Things like engineered floor and roof trusses do not necessarily cost more, or much more, than conventional construction using dimensional lumber. These items are so common thoday that the engineering is almost by rote. Included at the price at very reasonable cost.

cholland · January 28, 2013, 10:40:50 PM

20 ft. Is a good width. I put a center beam in my floor just because I wanted to make sure there is no bounce. Something wider than 20-24' is probably going to have a dividing wall anyway. If wanting more room I would also consider side add ons like the Victorias Cottage design.
As long as the engineered lumber comes with specs. You shouldn't need engineered plans if you stick with standard construction techniques.
Basements have many things to consider. If you don't have water table issues, they aren't too hard. Depending on what you need for footings (freeze depth) adding another foot or two is pretty easy. Especially if you are doing most of the work yourself, the cost is not much more. If your planning a two story, the stairs take up space. Might as well go down too.

I just have crawl space. I poured a perimeter wall with piers down middle. My site looks pretty flat, but it still has a 20"+ drop from the back corner to the front. I only needed a foot to frost depth. The downhill side of my foundation is a 4 ft. wall. It all starts to add up.

January 29, 2013, 09:04:34 AM

UP in Michigan so we have 48" frost line. And boulders way to often. And rock shelves. So location on property will not be my first choice if I go full basement. I have even toyed with post and pier - part of initial reason to enlarge and stretch since getting basement will be a royal PITA.

I had thought of using the 20 x 30 w/ loft and then doing a kickout with some Victorian add-on flair but somewhat worried I may be getting in over my confort level on the framing then. (?) I suppose I could sub out parts of that if need be.

Maybe I need to order both plan sets and then get a pencil and graph paper and start fresh and re-think it all.
Lots to digest _ again. $:-\$

mgramann · January 29, 2013, 10:05:07 AM

I'm currently building a "stretched" 1 1/2 story in the U.P. right now. Floor trusses were marginally more, and have many advantages.

Here is my thread:http://countryplans.com/smf/index.php?topic=12814.0

RIjake · January 29, 2013, 10:06:17 AM

Joe,
Mines a 20' with 12" engineered I-joists 16" OC. They were $76 each. I have no supporting columns in my cellar. My subfloor is 3/4" Advantech and there is very little bounce in the floor.
If you want a 24' span, your lumber supplier should be able to tell you exactly what you need or go to Boise Cascade website. They have span tables. I'd imagine they're around $100 each.

mgramann · January 29, 2013, 11:08:12 AM

Quote from: RIjake on January 29, 2013, 10:06:17 AM
Joe,
Mines a 20' with 12" engineered I-joists 16" OC. They were $76 each. I have no supporting columns in my cellar. My subfloor is 3/4" Advantech and there is very little bounce in the floor.
If you want a 24' span, your lumber supplier should be able to tell you exactly what you need or go to Boise Cascade website. They have span tables. I'd imagine they're around $100 each.

Running the numbers, engineered trusses appear to be cheaper.

My floor trusses were about $4400 for both floors, and I have a FULL second floor. The trusses are spaced 19.2 OC, and mechanicals/plumbing can be more easily run through them.

Using I-Joists 16" OC, one needs about 30 per floor, so 60 if you plan to finish both floors as I did. That's $4560 for the 20' joists, $6000 if you want 24' joists.

If you get away from "free span" you may save a little money, but otherwise trusses seem the way to go.

January 29, 2013, 10:57:32 PM

I just priced out 11 7/8 x 20 I joists get them here for 29.50 a joist.

cholland · January 29, 2013, 11:21:38 PM

Don't be afraid of framing an add on or L shaped floor plan. Just think of it as two rectangles. It's no more difficult.
It helped me a lot to draw up my plans using SketchUp. Use layers and you can draw as much detail as you need. I'm no architect, I'm a biologist. I drew all my own plans and got a permit in California following the 2010 code. What I submitted was just the floor plan, foundation, wall detail, etc. but in the other layers of the model I have every stud, header, joist, etc. it helps so much to be able to visualize the placement of things and how it ties together and everything. I'm using trusses so I didn't have to get that part exact. For a small deposit the truss company provided the specs and drawing for the permit.
Start small with SketchUp. I drew and built an 8x12 shed first. It's an amazing piece of software for free!

Don_P · January 30, 2013, 12:07:35 AM

ditto on sketchup

RI are you sure on that price for tji's? The ~$30/20' is correct around here too

. IIRC a "standard" if there is such a thing, floor truss for a 24' span is 19" deep, this factors into things like stairs if you clearspan vs a stick framed floor about 12" deep if there is a center load bearing wall.

RIjake · January 30, 2013, 08:47:16 AM

Quote from: Don_P on January 30, 2013, 12:07:35 AM
ditto on sketchup
RI are you sure on that price for tji's? The ~$30/20' is correct around here too . IIRC a "standard" if there is such a thing, floor truss for a 24' span is 19" deep, this factors into things like stairs if you clearspan vs a stick framed floor about 12" deep if there is a center load bearing wall.

Yes I'm sure. Don you're looking at the 20 series that can only span 16'-17'. Those are around $30 a piece. Mine are the 40 series and have an LVL top and bottom. That series can span up to 24' at 11 7/8". The 20 footers ARE $73 a piece.

To the OP. Make sure that you do your homework here and check the span tables from the manufacturer. Unless you want lally columns in your basement.

RIjake · January 30, 2013, 09:01:55 AM

BTW. They are Boise Cascade #30594745 in case you want to compare apples to apples.

Don_P · January 30, 2013, 02:00:20 PM

Good catch!
Definitely go by the manufacturer's span tables.
I just checked my GP booklet, do consult the booklet for the manufacturer available to you locally. They are being a little bit of salespeople in it. The first tables are for what they call "improved performance", and I'm all for using those tables. The tables buried at the end of that section have "code minimum" columns.