Need some advice

[Maine]

I am in the design stage of my garage, initial goal is 30x30 with living space above. Here is a photo of my house, garage would be going to the right:

Looking to add a garage like this with living space above:

I will be doing the build myself start to finish, and as I sketch it up i've come to the following:

I plan to use 10' 2x6's for the walls, and was going to use 16' 2x12's for the floor joists with a metal I-beam down the center between the 2 doors to support the floor joists where they meet. I am going to stick build the roof/truss.

As I do the research I realize that I would need a massive I-Beam, is there a better way to do this?

Thanks so much for any help, most of the garages around here utilize a standard truss with no attic storage/living space.

 

[p_mori7]

Welcome to GJ !

I would contact a truss manufacturer before commiting to a steel beam & stick built roof. Perhaps they can manufacture trusses to accomodate your span & desire for living quarters.

If committed to a steel beam, perhaps you could shorten the span by resting the beam on perpendicular stub walls. Think in between the garage doors, a short 2' wall front & back...would reduce your span from 30' to 26'.

 

[Maine]

Good idea with the stub walls, thanks a lot.

I am by no means commited to a steel beam, will check with a truss company tomorrow, I am just concerned with price.

 

[rslaback]

I would go with a TJI. Also, you may not get as high of a wall as you want. Your first floor wall height will be determined by the second floor. Unless of course you dig down for the garage or you put a step in to the living area above the garage.

 

[Maine]

The 2nd floor is 11.5' above grade, so a 10' wall will bring me within striking distance of being level once the frost wall/sill is installed.

 

[RobSmith]

If you play with cars consider the fumes....my cousin has a garage under his house and gets into all sorts of trouble with the missus when he starts a car...the fumes and noise work their way up into the living space.

 

[holland_patrick]

PS go bigger then you think if you can... if your set with a 30X30 room up above maybe you can bump out the back and put a 12x30 shed like area along the back???

 

[DonIvey]

PS go bigger then you think if you can... if your set with a 30X30 room up above maybe you can bump out the back and put a 12x30 shed like area along the back???

I did that and use the space to store compressor, gas cans, lawnmower, etc., and I don't have to clutter up my garage with it. No matter how big you make the garage, you'll always want more space eventually. Be sure to make concrete at least 4" thick, and if you want to put in a lift, add a thicker section where you will put it. Lifts are great!

 

[Maine]

Okay guys thanks for the input. I settled on a 28 wide x 30 deep with a car port for my boat, directly attached to the house. I was going to detatch but my lot/driveway wasn't ideal for that.

Building permit in place, excavation to start tomorrow!

Using engineered attic trusses, no fancy beams, etc. to worry about.

 

[IONH]

Sounds good. Be sure to start a new thread (you can link it in this one) so we can follow along with your build.

 

[wnstwolf]

If you have living space up above Insulate the heck out of the space beteween garage and the upper area. I have helped two different homeowners that had a design your looking at and the upper area became a huge master bedroom. It was beautiful space but no matter what they did they had a cold and heat issue due to the garage below. We ended up putting in small electric heaters set to 55 to temper the space below in one and the other had new duct work run under a cavity between the garage and living space to try and keep the floor warm.. Good luck with your project it will be a great addition to an already nice house.. as mentioned keep us posted

 

[woodrail]

Use caution with attic trusses! Although they will "hold" you, I'm betting you won't like the bounce in the floor! You obviously are putting a big investment on the table, don't go cheap on the structure. You may regret it latter.

If it were me, I would either go for a conventional frame with a center steel beam or I would look at engineered floor joists.

I also agree that you need to beef up the protection between the floors. I would give serious thought to having someone come in and spray foam the floor. I would then go an extra step and provide a vapor barrier and additional layer of gyp. bd.

If you have ever seen Holmes on Holmes, he gives great examples of moisture protection.

 

[Maine]

I had attic trusses quoted at 60 psf which I am told is very heavy duty, They use a 2x12 as a base cord. My friend has a newer house with just 2x6 joists and they do bounce, trying to avoid that!

 

[Maine]

Thanks for all the input guys, at this time I am not going to have house access to the area above the garage, this will be my wood shop/workout room/man cave, but things may change.

Link to build thread:

http://www.garagejournal.com/forum/showthread.php?p=2519792#post2519792