New here and considering a 20x40(30) - some questions

[Kach]

Hello everyone!  This is my first post and I'd like to say I love the forum and have been really inspired by all of the builds.


We are planning on trying to work with a 20x40 1.5 story plan.  We're playing around with different options for the floorplan while we're shopping for land (and cruising Craigslist looking for interesting materials to incorporate).  We are building this to be the new family home and I'm hoping to complete most of the work myself. 

One thing I haven't seen and am wondering if there is a way - I'd like to have a full loft using the 10'  sidewalls but have an approximate 12'x12' cutout over the living room area that is open with full loft still over the dining part.  This is our compromise to provide some extra TV/play area for the kids but still keep the open effect.  Is there any way to pull this off?  What truss design? 

What is the most efficient stair design that is up to code?  What would the approximate footprint be?  I would like L-shaped stairs that come out of the living room along the long wall and make a 90* angle up to the loft.  Can this be done with with a 12-12 pitch roof and have enough headroom to meet code?  I'm wondering if more than half of the steps were on the initial run and then the remaining few after the 90* turn/landing if that would leave more open loft space.  It will be technical because I can't be too high when under the lowest part of the roof. 

Also, does anyone have a sketch of the elevations for the loft trusses (10" walls).  That would help me plan the upstairs floorplan.  I'm still getting a feel for what I can and can't do with framing...

Hoping to have my ideas all worked out and get the plans soon!

[MountainDon]

 
One way to open up the space under the roof and above the walls is to use a structural ridge beam instead of trusses or standard rafters with a ridge board.  That would need supports at each end and at least one someplace between that extend right down to the foundation. The columns do not need to be one piece; the path from beam down to the foundation needs to be complete though. One or two intermediate support columns can be used, they don't need to be evenly spaced as long as the beam is sized for the loads.  Then regular rafters are hung; the top end is supported by the ridge beam (half the load) and the lower end by the side walls (quarter of the load each). Just a thought.

[Kach]

Thanks for your thoughts!

I like the ridge beam look, but I'm guessing that might take this beyond a DIY job for me (how do you get that thing up there?).  I also wonder if that would be cost-prohibitive in my budget-conscious project. 

I'll have to look into the rafters with ridge board idea.  I haven't used that type of construction before.  How would the 10' side walls be tied together without the lower chord (floor joist in this case) that is in the rest of the house?

[MountainDon]

How would the 10' side walls be tied together without the lower chord (floor joist in this case) that is in the rest of the house?

That is the problem... the wall tops need ties to restrain them.  That is an advantage of a ridge beam. There are no horizontal forces on the wall tops.   You could combine rafters or trusses where an upper floor is desired and then a ridge beam (with proper supports) over the area where the ceiling is wanted to be fully open (cathedral).

At a 40 foot length though there is need for a lateral support, like an interior wall. Twenty five feet with no brace walls is the code limit. But with a bedroom or something towards one end, there's the brace wall.

[Don_P]

I'm still getting a feel for what I can and can't do with framing...

How would the 10' side walls be tied together without the lower chord (floor joist in this case) that is in the rest of the house?

If there is a sidewall... 1.5 story, then the floor is not a tie. Scissor trusses or a ridgeBEAM are options. Another way would be to raise the sidewalls until a tie across the lower third of rafter height is at ceiling height upstairs. This might help with the stairs and headroom as you climb all depending.

[Adam Roby]

...that might take this beyond a DIY job for me (how do you get that thing up there?)

One idea is to build any laminated pieces in place.  So rather than lifting a huge piece into place, if you will be nailing say 4 2x10's together for example then you would put one in place, then nail the second, third and fourth in place.

Google has a lot of tips on working alone.  Someone here recommended a book to me which I bought, I will find it and give you the name.  Is it essentially a bunch of tips and tricks, and different tools (or jigs) you can build when working alone.  There are a lot of good recommendations in there. 

Found it:    Working Alone, by John Carroll

[Kach]

I'm still kicking around ideas...  I'm wondering if I can keep the 1 1/2 story somewhat reasonable (for me) to build and also get the ceiling heights I was hoping for.  I'm starting to think about going to the full 2 story.  We're a family of 5, so it probably makes more sense. 

Is the 2 story universal an easy plan to extend out to a 20x40?  We have a pretty solid 1st floor plan we like for that footprint with a downstairs master bed. 

What does the framing look like to get the open beam effect on this first floor:

http://www.countryplans.com/sky-holt.html

My wife loves that and it partially makes up for no open loft. 

Thanks again!

[UK4X4]

I'm not sure on the actual construction of that build

but for the same effect, faux beams can be added to give you that look

or you could look at having a solid floor and use bigger joists to give that open look

Engineered timber for beams and trusses should not be discarded for cost, as you may well end up using a lot more sticks of 2x to acomplish the same thing.

we did a lot of changes to our house, the scary cost of trusses, dissapeared when we looked at engineering costs and the labor time to stick build the roof.

we used scissor trusses to give the height, and a 6ft side wall platform framed.

it made such a wondefull space we completely changed the house design and reversed the living areas

[Kach]

Still sketching away on this and looking into different ideas...

One idea that I'm considering and wouldn't mind a bit of feedback on is a version of the 1 1/2 story.  I was inspired by the Alaska cabin in the gallery and the dormer look.  I'm thinking about maybe going with 20x40 1 1/2 story cottage with 3 dormers on each side of the roof peak (equally spaced, with the opposing dormers lining up).  I could do platform construction for 1st and 2nd floor which might be easier to frame myself.  2nd floor platform construction would give me the ability to put in a 2-4' knee wall giving more living space and maybe a 9' ceiling downstairs.  I worked out a plan to pretty much fit a whole bath into one of the 6' dormers.  Gets more usable space in my smallish bedrooms up there...

Is there a way to get the open loft effect with 2nd floor platform construction?

We may abandon that concept for more living space and a higher ceiling height downstairs. 

[Don_P]

Building without ties in the lower third of roof height generally requires either a ridgebeam or engineered trusses. That is not a deal breaker. Using heavy timber beams rather than dimensional lumber to support a floor or open lofts is also quite do-able. The pics you linked to look like the beams were for effect rather than structural but they can be either depending on size, span, species and spacing. The spacing on those is a bit wide for a typical heavy timber floor, generally I've spaced the joists at 32" spacing with a 2x plank floor/ceiling overhead. For the effect they achieved there are joists above the exposed beams and conventional floor and ceiling finishes. There are pluses and minuses to each approach. Either could have an open loft/ cathedral section if desired.

[Kach]

I think I'm down to pretty much 2 possibilities for the basic structure:

1) 2-story 20x40, Platform construction on crawlspace foundation with 8 or 9' ceilings first floor.  7 or 8' ceilings 2nd floor with vaulted (scissor?) trusses.  Hoping for a less steep roof with a still nice vaulted effect inside.

2) 20x40 1.5 story, Platform on crawlspace foundation with 9' first floor ceiling.  2nd floor built on a 3' knee wall with 12-12 pitch roof, 3 sets of opposing 6' dormers (3 on each side of the ridge).

The floorplan would be similar for both (with a few tweaks due to ceiling height upstairs.

[UK4X4]

I'm within 6ft of you on dimensions mines 26 x 36

crawl space foundation, open first floor ceilings, upper 3/4 storyish

I have 8ft high second floor beams and almost 9ft to the floor above
Upstairs is midway between your design with a 6ft side wall and scissor trusses

Upstairs came out so nice it would have been a shame to use it as bedrooms, so we moved the living area up into the trees !

my scissors are 10/12 outside and 8/12 inside and still give me an attic over the master bed

My dormers only added to the look, they serve no real purpose other than adding detail to the outside, with large overhangs we went with 2 a side ,less work than adding 3off per side.

Made the upper deck workable and not covered in snow, only direct snow fall and not the roof run off

http://countryplans.com/smf/index.php?topic=9588.0

We all come into this with diferent views and wants, and as you go into your build always consider changes along the way, its not set in stone, the general contractor basicly stopped the job once he got the roof on and saw the space we had, he refused to put in the planed walls untill we'd seen it

We are so pleased with our upstairs great room, looking out the windows into leafy tree's and out across the valley, while downstairs has become a homely, more closed in cosey area, with the design changes we even added a second living area downstairs as well.

[Don_P]

some thoughts,
a 6' dormer has 5' of interior width... don't forget to draw in wall thicknesses. A long shed dormer has more useable space than several small gable dormers but it is a different style. Sheds are easier and cheaper to build and probably cheaper to maintain since they are not valleyed. When you start articulating a roof like that, popping elements out of a basic gable, a ridgebeam really begins to shine.