Liberty Nature Preserve

 

A garage?  A cabin?  How 'bout 2 in 1?

Follow us as we build a garage/apartment at LNP

Designing the structure

Since we are backing into this building site development by constructing the garage structure first, we need to really think smart.  We have considered and dreamed about what type of house might actually wind up along side of it on this new blank canvas.  We are also well aware that by the time we weather the many years to get to that point, alot of things will change.  As a result, it is impossible to accurately predict house style.  The only sure model we can assume is that our natural surroundings will dictate a future home design that blends in a country kind of way.  This pretty much eliminates contemporary designs....or at least it affirms our dislike for that type of home design in the first place.  This is about as much design guidance that we have to go on as we consider our current challenge:  designing a suitable garage.  It has to be a somewhat universal and classic look.  As much as we want to really put a super effort into making this garage structure a "showcase", we actually have to go out of our way to keep it somewhat muted.  When the main home structure arrives, the garage should be somewhat of a shrinking violet as it plays second fiddle.  It must be constructed and finished knowing that it is a secondary structure.  Prim, proper, but not too ornate.

 

The first design consideration was the simplest, most basic structure of all; a box with a gable roof.  Immediately, my dream phase kicked in and took it to a 2 story structure.  I found this plan on the www as a stock plan.  We really liked it...

OK, very nice...but...a bit over the top.  We didn't knock it off the radar, but kept thinking and looking.


The following steps are my design efforts.  I have a design program that really helps in visualization.  I put it to work.  I haven't mastered the fine details of creating perfect renderings, but it provides enough of a "feel" to sample and adjust different design ideas.


This next design is nothing more than the first design, less the stereoids.  We wanted to tune it down by keeping it to a 1 story structure plus use of the attic space; also known as 1 1/2 stories.  The 12/12 roof pitch would maximize the attic area for elbow room.  It came out something like this:

Nah...don't think so.  The deck would be cool for lounging, but looks dorky and "slapped on".  We removed the deck and wrestled with it some more.  A major problem was going to be window ventilation at the second floor.  Since we are using a metal roof, I didn't want to start cutting holes for roof windows, let alone the cost.  Dormers would be OK, but at that point we might as well build the 2 story model.  There were a number of other logistical constraints that was making this basic design a loser for our goals.  We probably could made it work, but it just wasn't the "right one". 


So, I get me another one of them lightening bolt ideas.  It's a barn design, that is pretty cool...at least it's cool as a barn.  It's called a "monitor roof" design.  I start by going nuts and adding on that front deck that I am so sure we will need.

Hmmm....sure seems practical...but...we are still having issues with "the look".  It became another wrestling match, removing the deck, changing the shape, desparately trying to make it work for us.  It morph'd into this:

Oh boy, this just isn't feeling right.  More pushing, pulling and tugging at the exterior to try to find something that works.  It's just not comin'.  Moreover, we are realizing that the second floor has a considerable square footage restriction with this design.  It's not much more than 15 feet wide and seemed to be a low return for what we seek.  After much thought, this one also got scrapped.


There has always been a classic design that hung out at the periphery of our "design radar", but we were avoiding it simply because we already got's one.  It is the gambrel roof barn.  Some 10 years ago, we built this exact structure as our garage at our primary residence.  I guess we just wanted to try something different, but it kept coming back to remind us every time we looked out the window into the back yard.  We have often stood up in the second story of our garage and thought how cool it would be to have that space developed for living quarters.  Well, it has now moved dead-center on our radar and has once again achieved status as "the chosen one".

This is a pic of the structure we built for our home. 

This is set on a 24' x 36' foundation footprint.  The new building at LNP will be 28' x 44', but very much the same building plan and aesthetics.  I had to adjust some of the roof angles and pitches to optimize the look of the wider stance at 28', but overall, it will look very similar to this one.  The shed dormer will be constructed at both sides of the roof to yield additional square footage at the second floor.  So, let's move along with this plan and get serious...



Here are some basic construction criteria planned for the new structure:

  • The foundation footprint will be 28' x 44'.  This will provide 1200 sq feet on the ground level, to be reserved as garage and shop space.
  • The foundation will be a poured footing with 4' tall x 8" thick concrete walls.  The slab in the garage area will be 5" reinforced.  The slab in the shop area will be 5" reinforced and poured with Pex radiant tubing incorporated.
  • The ground level walls will be 9 foot tall.  This will allow 8' tall garage doors to facilitate access of smaller tractors with roll-over-protection-devices extended (ROPD).  The 2 garage doors will be set as side loaders.
  • The second floor framing will be clear-span engineered I-joists and laminated veneer lumber beams (LVL).  In order to make the 28' span without posts and supports, they stand 16" tall on top of the first floor exterior walls. The 3/4 plywood decking is attached to the top of this framework and the second floor framing goes up from there.
  • The second floor will be all living space.  It will come in at 1100 sq feet. 
  • The shed dormer stretches for 36' along the 44' length of the structure; 2 identical dormers @ each side of the roof 
  • The roof framing will be largely constructed of pre-fabricated roof trusses; specifically scissor trusses.  All the roof framing over the shed dormer are scissor trusses.  The 2 shorter roof sections at either end (at the gambrel roof sections) are scissor trusses on the top pitch of the roof.  The steeper gambrel sections are stick-built on site
  • The scissor truss design will give us a slick cathedral ceiling through the entire length of the second floor living space.  At the peak, the ceiling will be 11' tall.  We will run the few wall partitions for the bedrooms and baths all the way up to the cathedral ceiling. 
  • The roof will be a standing seam metal roof
  • The siding is cementitious lap siding; 7" reveal.

Here's an exterior view, to get a feel for the project   

 

This is the upstairs floor plan.  This could change some, but the basic layout will work.



Juice, water, and waste...

So, let's back up a little to talk about the necessary utilities.  You know, stuff like electricity, water, sewage disposal.  No biggie; just a few minor details.  Yeah....right.  What a pain.

OK, let's start with power.  When we started this LNP project way-back-when, the first big project was to cut a road in from the county road to the pondsite.  As part of this project, we had to plan for pulling in electricity.  Before we even fired up the bulldozer, we called in the power company guru to review our driveway plan.  He walked with me thru the woods and  to advise what we needed to prepare during the gravel driveway construction.  Since that time some 4+ years ago, he has returned 4 times to bring us to this point.  We got his installation estimate earlier this year.  Yikes!....but it wasn't any surprise since we knew pulling juice over 2000 feet underground wasn't gonna be chump change.  Quite frankly, it was very fair considering the work and costs involved.  They are going to run an overhead line from a pole on the other side of the county road.  It will run to another pole on our property at the county road.  From there, it heads subterranean.  Down the pole and into the ground.  It will follow the gravel driveway from this point, all the way to the building site.  The part that runs thru the woods (about 1500 feet) will have to run inside PVC conduit.  This is because it will be pinched up tight to the edge of the driveway.  During the trenching process, the chances are high that rock from the driveway base might fall into the trench and compromise the direct burial power feed insulation.  Knowing this, I found a great deal on PVC conduit on Ebay about 3 years ago.  It's been waiting in storage.  There are also 2 areas that will require directional boring (I think he called it a mole...?)  These areas are logistically impossible to run the trencher through, about 40 or 50 feet long for each.  They will bring in an independent contractor to push a flexible conduit underground with a directionalized boring machine, then tie it into the PVC conduit they are trenching in.  Where the power arrives at the building site, they will run it to a transformer on a small concrete pad.  From there, I have 15 feet maximum to get it to a meter.  We discussed the amount of power I want set up for.  Well, I know that 200 amps is normal for a residential structure.  I share our long range goals with our power guy and he suggests that we might want to consider a 400 amp service.  He said the upcharge is $275 at installation and nothing more.  If I run it all into one meter, there will be only one service bill and we pay for only what we use.  In other words, why not?  He explains that we can come out of the meter base with two separate 200 amp power lines.  If we attach the meter to the side of the garage (as we plan to do), one 200 amp feed can go directly into the garage and power the breaker box.  The other 200 amp feed will go from the meter base to an exterior disconnect next to it and sit there waiting to be tapped for the line to the future house.  Yup; that's the plan.

And then there is water.  All things considered, it will likely be the lowest level of engineering and overall cost.  I have the well drilling records for 4 different water wells, all within about 2000 feet.  They range from 75 - 140 feet deep.  In fact, the 75 footer is the home directly north of us by about 500 feet.  When the time comes, we should have no issues with drilling the well.  (knock on wood)

And finally, let's talk about sewage disposal.  More accurately, a septic system.  This is a story in of itself.  When we started planning for the pond excavation, after all the trees were removed in the pondsite and building site, I was already thinking about where to put a septic system.  I called a couple of installers to get a feel for the amount of real estate we will need for the tank and field.  Given this input, I had to plan enough room and far enough from the pond.  Since the building pad slopes downhill from the back and toward the pond the easiest and obvious field would be right next to the living structures, between them and the pond.  The concern was that the pad would be constructed largely of fill removed from the pond basin.  The septic field would be installed into fill.  I already knew this might be questionable for zoning approval.  I called the county health department and talked to them.  The bottom line?  If the soils perc correctly, it's fine.  What?  I couldn't believe it.  I waited for a week and called back to discuss it again to make sure I understood.  I did.  Wow; hard to believe, but good enough for me to move forward with planning a field in the fill we bring in from the pond dig.  Fast forward 2 years to last fall, November 2008.  I contact the health dept again and tell them we are getting serious.  He faxes me the list of independent soil analysis contractors and tells me to get 'er done.  I called 3 of them.  They all run about $275.  I go with the guy that has a schedule that works with mine and we meet at the site.  We walk out onto the building pad and he asks me where the field is going to be.  I point to the wide open space out in front of us as we stare across the building pad and out over the pond.  We start walking over to that area as he asks me if there is any fill in this area.  I tell him it's all fill.  He stops like he just saw a rattlesnake, looks at me and says "you can't install a septic field in fill".  I felt that queasy feeling come over me that quickly kindles into anger.  I tell him my health dept story and he counters that he's not an expert, but as far as he knows, the state ain't gonna go for it.  He quickly adds that it's not unusual for local regulators to make up their own rules and trump state ordinances.  At this point, I can detect a little attitude and he is already totally negative on my plans.  He succumbs a bit and agrees to take a quick soil sample in the area out in the fill.  As he stands on the little coring tool, he's shaking his head and poo-poo'ing the way the tool is moving into the soil.  He pulls it out and starts telling me how lousy it is and that a septic field in this soil will fail quickly and likely send effluent into the pond.  This is definitely not going as planned.  So now he starts scanning all the adjacent real estate and asking me if I have a "plan B".  I am totally not prepared for this.  It's not like I can tell him to just forget it and we'll get together another time.  Yeah, maybe for another $275.  The only other option is our 1.75 acre field about 250 feet through the woods to the east.  OK, let's go.  So guess what.  He loves it.  He looks over the topography and starts talking it up as a great looking place to install a septic field.  He pulls his test cores and the warm & fuzzy continues.  Ultimately, he finishes the job, telling me that we will have to pump out to this field.  He delivers minimal consolation by explaining that it's not that big of a deal.  The main septic tank has another tank directly adjacent that receives the effluent fluids.  An ejector pump in the bottom of this second tank lifts and pushes the effluent thru a 2" or 3" PVC pipe (laid through the woods) and drops it into the distant septic field.  Definitely wasn't the plan....gee, thanks.  A few weeks later, I call my excavator (also septic contractor) to discuss the new plan.  He doesn't buy the bill of goods I got sold.  We plan to get together at the jobsite that weekend.  After we review the area, he is sure that there are other options.  He is disappointed (as am I) that i did not think to consider the back side of the building pad for a septic.  I freely admit that the uphill slope kinda knocked any consideration off of my radar.  He explained that just because the slope goes uphill does not mean the system has to go uphill.  He starts to relate some of the tricks for "digging it in" and "manipulating location and grade" to make it all work.  I feel like a dope, but a relieved dope.  He really thinks that we can still work in a conventional system at the back of the building site where there is little to no fill.  That is the key; working in an area that has very little fill.  Like I said; kinda dopey for me.  He says that he knows the health department inspector and thinks that he might be able to get him out to the site to render an opinion.  This is really starting to sound much better.  Blah, blah, blah....long story shortened, we get the green light to install the septic field behind the structures, slightly uphill and at the back of the building site.  All is saved and we breathe a sigh of relief. 

During this last meeting with my septic contractor, I also had the power company rep meet up with us.  Between the 2 of them, they were able to come up with a layout for the septic field and the electric feed that would not conflict.  Actually, it is pretty simple and works great.  Of course, the water well installation was part of the discussion and it now has a home zone, also.  The pieces are starting to come together and it's lookin' pretty good. 



Back to the project details...

Once we set our sights on the gambrel roof barn design, I had to come up with some drawings.  Since this is really a pretty simple design, I could probably take my time and build it on the fly without plans....but they do help.  Moreover, I needed to present something to get the concrete bid.  I also needed drawing details to get bids on the second floor joist system and the roof trusses.  I got out my old drafting tools, blew off the dust, and started drawing.  At first, it was a bit overwhelming, but page by page, drawing by drawing, it came together.  As I continued along, each drawing pointed out the need for another detail drawing.  I really came to appreciate taking this time.  It forced me to consider a number of details that I had originally just waived off as "no biggie; I'll deal with it when we get there".  It's these few little details that will help make things move smoother and give that extra boost of confidence as we move along.

So, out go the concrete plans for bidding.  I sent them to 3 guys, all recommended by 3 different folks.  So far, only one has come back and it's not really that bad...but...it's enough to make me want to take on a large portion of the concrete work by ourselves.  Seriously!  If we can save 3 or 4 grand by DIY concrete, it's pretty hard to say no.  Remember, we've done this structure before.  To be honest, when we built the first gambrel roof garage at our principal residence, we paid a concrete contractor to do the foundation.  I watched and learned.  It's not rocket science.  I really think that we can handle most of it by ourselves.  We will see....

The wall framing, windows, and doors at the ground level are cake.  Nothing special here.  The second floor joist framing is a little different.  When we did the first garage, we used a 4" metal column in the center of the garage at the ground level to support the floor framing for the second floor.  At the time, it seemed to be the best decision.  Now, having gone thru all the hassle of pouring a concrete pad, setting the column, putting up a beam, and then attaching all the individual I-joists at both halves of the framing, I want something easier.  Besides, I would love to nix any columns and have an entirely open area at the ground level.  This would mean using some sort of framing plan that will span the 28' width.  I submitted our framing plans to a local engineering firm that supplies Menards with structural lumber products.  After numerous phone calls and exchanges of ideas, they came up with an engineered I-joist design that will span the 28' distance and still have the guts to support the live load at the second floor.  I knew it was gonna be a tall framing section.  It came in at 16" tall....not really that bad, considering the distance and load.  They will have to be placed at 16" on center; no biggie.  Now I'm getting inspired.  I call Menards and have them quote these framing members.  Wow...a bit expensive.  Time to go shopping.

I hit the internet and came up with about 6 different truss manufacturers within striking distance of our project.  I put together an email introduction and scans of the framing plans for estimating the flooring system and the roof trusses. The bid package goes out to all 6 players.  In the end, only 2 are interested.  One will sell me factory direct and one will only sell me thru the local lumber yards.  In the end, the factory direct option paid off big.  I really liked my contact and the attention he gave me from day one.  He made me feel like our project was his own and he really spent time helping me tweak the structural design.  All this, and he came up with a package price that blew away the competition by about 25%.  The inspiration continues.


In my scheming, engineering mind, I had planned on keeping it simple and using trusses that would provide a flat ceiling inside the structure.  This prompted the first demonstration of inspiration and interest by my selected truss manufacturer.  He looked at the plan and suggested that I consider a scissors type truss.  Huh?  He gives me the verbal description, only to be met by my hesitancy to believe that they would have the strength to suitably support the roof load.  Then he whips out the numbers and statistics of their engineered strength.  I relent to the idea and allow him to present some drawings.  Whoa; what a cool idea....a neat cathedral ceiling that I had never even considered.  There's even enough room to create a scuttle area inside the attic area.  I'm sold!

These are the roof truss designs.  Although we could get away with setting them at 24" on center, I'm not pulling punches and setting them at 16" o.c.  There are 2 truss designs.  The largest quantity of trusses are at the 36' long shed dormer walls.  There will be 28 pieces of this truss.

   

The above trusses covers 36 feet of the overall 44' roof length.  That leaves 8' of roof; 4' at each end.  These 2 short roof sections are where the steeper gambrel roof sections are also part of the framing.  At 16" on center, that means we will need 3 more at each end to fill out the entire roof framing.  Since we will be stick-framing the end wall trusses (the very last truss at each end, stick-framed because it requires special construction details), this means that we only need a total of 4 of the gambrel trusses.  My first instinct was to just stick frame those, too.  I figured that setting up a manufacturing plant to make only 4 trusses would be over the top expensive.  I found out to the contrary, and got talked into letting the manufacturer make those, too, as part of the entire package.  Hey, the price was right and it really makes framing this roof a piece of cake.  Here it is:

 

Another bonus is the weight of the trusses.  The shed dormer truss weighs 98# and the shorter gambrel truss comes in at 83#.  No cranes required for this job!


The second floor framing is another cool response to construction simplicity.  Georgia Pacific makes a 16" tall engineered I-joist that has the structural integrity to span the 28' when set at 16" on center.   

   

We are using the WI 80 series.  The 3-1/2" wide flange is really gonna make laying in the plywood subfloor a breeze.  I was concerned for the ability to run mechanicals thru them in the perpendicular direction (HVAC ductwork, plumbing drains, etc).  GP has that answered.  There will be 5 holes in each I-joist.  Each of these holes will line up with all the other I-joists to provide a direct shot from one end of the floor framing to the other.  See the perpendicular hole layouts in the plan below.  The largest hole in the center is 20" wide (rectangular) for a main HVAC duct.  The other 4 runs are circular, 10" and 8" diameter. 

 

2nd floor engineered I-joist framing layout

 


We just got back from cutting the grass on the building site and started brush hogging the brambles and clearing logs from the area along the driveway where the trencher will come thru to install the underground electric line to feed the site power.  With the building site trimmed and lookin' good, I got a nice pair of pics stitched together to provide a feel for our continued inspiration.

We are standing at the rear of the building site, about center.  The treeline is right behind us by about 20 feet.  The proposed garage/apartment will be placed to the left of us.   It will set between the camera and the dock/deck.  The right side of the building site will remain naked for some years to come, reserved for the dream of a retirement home.

 

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