Garage w/ Basement - 28x40

[vtjon]

I am finally getting around to starting my build thread. I appreciate much of the advice folks provided me as I was planning. Some of the earlier threads were:

• Fill Alternatives
• How to spec a suspended slab

In the area where I finally decided to build, the grade was substantial. It fell about 10' from front to back. In my research, I determined that filling the hole with rock was going to be expensive so I decided to build a basement with a suspended concrete floor on top. Although I researched many options, I finally settled on a beam and pan system as it was simpler, didn't require extra engineering (provided by the company) and a local-ish company provides a all-in-one solution so the AHJ are familiar.

We poured the upper slab last week. My excavation contractor did the dirt work, footer, basement walls and placed the beams for me. I decked the beams and placed/tied the rebar.

I hope to start framing soon which I'll be doing with some help. I originally planned for a ledge/stem wall to set the walls on but any concrete walls over 10' get more complicated/require engineering. As such, I am going to build 12' 2x4 stud walls. I know this is contentious but I'll be blocking it every 4'. I'll be back to ask questions and I'll be glad to answer any. I have a ton of pictures but will try to attach a few. I tried to get some "detail" on how some things are done so I hope it'll be helpful.

 

[vtjon]

More pictures

 

[vtjon]

Basement prep and pour

 

[vtjon]

Upper deck prep

• The conduit on the sides are wire sleeves and for my air lines.
• The larger, round 4" conduit is just future sleeves with screw-in caps
• The small boxes on the sides will be for dust collection
• The big box-out in the middle will be for a dust collection and power for table saw. Will cover with diamond plate steel at some point if I want to move it/hide it.

 

[vtjon]

Some final pictures from upper deck prep

 

[Macneil]

What are your plans for the basement portion? Perfect land set up for that!

Excited to see how this turns out.


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[harley jim]

Subscribed
Vtjon I really like the two story aspect how very cool. Double the floor space on the same footprint[emoji106]

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[vtjon]

What are your plans for the basement portion? Perfect land set up for that!

Excited to see how this turns out.


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I don't have any definitive plans. It is basically "extra" due to my site. I'll probably store a few things like a UTV, maybe Jon Boat. The wife and kids have suggested a batting cage or axe throwing lane.

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[CombatNinja]

Indoor axe throwing and kids--what could go right?

Cool build, I love these types of buildings when the site dictates it. Never understood why more people don't do it instead of bringing in tons of fill and building retaining walls. For the same money they could have a suspended floor and double their floor space. As a bonus, the basement tends to be pretty consistent in temperature for storing things.

 

[Pluribus]

This is going to be really interesting! Just caught myself about to make a comment about the below freezing temps in New England, but realized you're in VA and not VT; your username threw me.

 

[Boosted1]

That is a nice "extra".
Lots of things you could do with that space.

 

[Jawn]

What sort of limitations are imposed with the suspended slab?

(i.e., what's the load limit, can you drill for conduit penetration or fasteners to bolt machines to it, etc)

 

[vtjon]

What sort of limitations are imposed with the suspended slab?

(i.e., what's the load limit, can you drill for conduit penetration or fasteners to bolt machines to it, etc)

There aren't any specific limitations that I am aware of, at least for normal use. The engineering report was pretty simple. It's loaded for typical (code?) garage loads of 50psf live load and 2000lb concentrated load (I think).

You can core drill the floor if desired though you'd want to make sure to miss the rebar. It works out much better to sleeve it beforehand as I did.

In my discussions with the company, the beams take all of the load once everything sets though you leave the metal decking in. The box for my table saw is something like 20"x12". It might crack at the corners but it's sturdy (rebar into the box a little).

I could have put anchors in the floor though I decided not to because this is mostly a woodshop. At 28' feet wide, I'm at the widest clear span and the beams are pretty close together (69"). The beams are 14" tall. I also did not spec a lift though they also sell posts that could have gone under the floor.

The biggest risk to this floor is road salt from cars. It's somewhat common for the salt to corrode the rebar and get to the decking especially if you wasn't sealed properly. We used a top line "diamond sealer". I'll probably apply something else or another coat once dried in.

The concrete is relatively thin at 4.5" to 4" around the drain. It's the max you can pour. I did get told some stories with some failures when folks poured too much.



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[vtjon]

I hope to start framing later this week. Any opinions on garage door size and window header height?

The garage will be framed similar to my house (w/ attached garage) including finished in the same siding, style/color garage door (white w/ lites though simple) and hip roof. My house has an 18'x8' door. The garage walls will be 12' so I am thinking 18'x10' but I wonder if it will look out of place. The new garage is not beside my house but behind it maybe 20' (you can see in the earlier pictures).

On the windows, I am going to have 2 windows on each 40' wall. I want some simple venelation and light. I am thinking about doing 36"x36" windows and set my window header height at 86". I want to reach my windows but still have room for a 4x8 sheetgood or workbench to go under. These will be a little higher than my doors of course. Thoughts?

 

[el monte slim]

Cool build, I love these types of buildings when the site dictates it. Never understood why more people don't do it instead of bringing in tons of fill and building retaining walls. For the same money they could have a suspended floor and double their floor space. As a bonus, the basement tends to be pretty consistent in temperature for storing things.

I completely agree, and will look forward to vtjon's continued progress on this build.

 

[vtjon]

Seems like it was about time for a new update since I'm to a new milestone. I have all 4 walls framed. It was a lot of work. My wife and neighbor have been extraordinarily helpful.

Most walls were framed and sheathed in 16' sections. We used a variety of ways to stand them as my original plan for a home-made lift didn't work.

I bought a Harbor Freight 2500lb ATV wench which ended up being very helpful. I have a side-by-side UTV with a 2" receiver where I mounted the winch. On the first wall, we mounted the winch to the wall itself then pulled against a tree. On the next wall, I created a crane out of an extension ladder and a pulley block. On the other walls, we were able to get the UTV out far enough to just pull it up. The smaller 8' sections and the rear wall with limited sheathing, 3 of us stood it by hand.

I've ordered the trusses but will be hiring a crew to frame the trusses and shingle it.

 

[vtjon]

more pictures

 

[Kevkx125]

Cool build for sure. Sounds like a pretty cool plan going can't wait to see how this turns out.