Replacing columns in Garage with Steel I beam.

[GordonGriggs]

I have a 24x24 garage with an apartment above it. It has 2 8 foot wide doors, and a center support with columns. I want to remove the columns and put a steel I beam down the center just below the 3 2X10's. This way my garage will be open in the middle. I can only put 2 cars in it now the way it is. If I install a steel I beam I could squeeze in 3 cars. Photo's below. But my question is does anyone have a similar setup? I need to find out what size I beam to buy.

Here is my garage from the outside.



Here is the center beam made of 3 2x10's. I want to run the I beam just below this and install columns at both ends of I beam.


Here is a photo of how much room I have between the 2 cars. I can move both of them closer to the walls which will give my plenty of room
for another car between them.

[bakerhillpins]

I don't think buying the beam is your biggest problem with this change. It's going to be supporting the beam. Where are you planning on putting the supports? Will you build it into the wall cavity or put the supports just on the inside of the wall and the supports on the concrete floor?

You will need to make sure that the floor or your foundation can carry the point load from the beam supports. I would bet that the garage floor would need cut and a footing poured.

[GordonGriggs]

Im going to use seperate supports for the beam, one on each end. The footings are wide enough, I dug and poured it back in 1990. To support the floor while removing the current supports  use 6X6"s. Ive figured out how to do it without it falling down on me.

[RallyeMike]

The answer depends on your floor design and loading from above. Does the roof load down through a center wall and onto the beam? You could make an educated guess, but I would call a local Civil Engineer to give you the correct answer. It's not just the size of the steel beam, but the type and thickness of the flanges and web. A gluelam or other type of composite beam may also work.

[Old Moparz]

I agree, you need a professional engineer or an architect to help you determine the size of the beam you need. When I built my garage I didn't want columns in my way either, so I had an engineer calculate what size I-beams I had to use based on the rest of the building design.

[NHCharger]

Find a local company that supplies steel beams. If they don't have an on staff estimator, their supplier will. They will calculate the size of the beam for free. Since your roof line is running opposite of your floor joists I'm going to assume you have roof trusses.

I replaced an undersized microlam beam with a steel beam for a friend a few years ago. I checked with two different suppliers and got the same answer on the beam size.

On a side note, how old is the house? IBC code requires a 1 hour fire separation  between the house and garage. If you have a fire in your garage your current set up gives your insurance company an "out".

[Darkman]

You will find that a laminated beam for the ceiling would be the best to support the appartment above, however to span such a big distance (ie only supported at the ends) you will need a big beam. You will lose height. Then you will have the issue of a single column in the middle of the garage (if I understand what you want). You can upgrade to make one big openeing in your garage but that will also require increase load distribution (increase in lintel beam size) to the sides of the doors. This way you have no supporting columns in your floor space and the centre of your garage. It can be done, but there would huge rework needed, engineering calculations and sign off. The footings in your garage maybe suitable (without knowing the size of them) but they also may not be big enough (deep mainly) or with enough reinforcement in there to support the weight. Currently, the weight of the appartment is nicely distrubuted by the wall between the current 2 doors

[GordonGriggs]

The roof does have trusses. Im Ok with the 2 doors the way they are. One big door would be nice but I don't want to do all that work. Plus, I don't want to have to redue the siding.

Thanks for all the replies. Im not sure what Im going to do. I don't know anyone in this area I can trust enough to do the work. Plumber's, electrician's, and carpenter's in this area are really unreliable which is why I learned how to do those things myself. I had to call 10 different people just to get 1 estimate on doing the foundation for the shed I built in 2007.

Thanks!

   

[stripedelete]

You will find that a laminated beam for the ceiling would be the best to support the appartment above, however to span such a big distance (ie only supported at the ends) you will need a big beam. You will lose height. Then you will have the issue of a single column in the middle of the garage.

Darkman,

I'm working the same problem with my garage.  Please clarify.   Given lose of height is not an issue, are you saying that even with a large laminated beam you will still have one post at the midpoint of a 24ft span? 

[NHCharger]

Stripe. I built a house with a 24x26 attached garage with a family room over the garage. I used a glue lam beam called a power beam. Not sure if that was the name of the manufacturer. It was 8" wide by 18" deep. Spanned the entire garage without a support column in the middle.
It was also a trussed roof so there was no load on the beam other than the floor.

[Darkman]

You will find that a laminated beam for the ceiling would be the best to support the appartment above, however to span such a big distance (ie only supported at the ends) you will need a big beam. You will lose height. Then you will have the issue of a single column in the middle of the garage.

Darkman,

I'm working the same problem with my garage.  Please clarify.   Given lose of height is not an issue, are you saying that even with a large laminated beam you will still have one post at the midpoint of a 24ft span? 

You can get any laminated beam to span any length you want, however the size increases. You can eliminate supports in the middle if the beam is big enough.

Gordon, if you are keeping the 2 doors then you shouldn't have a problem and the centre beam shouldn't need to be too big. In any situation, you will need it engineered.

[stripedelete]

Thank you.   I just wanted to make sure I had not come to the wrong conclusion.

[Darkman]

Thank you.   I just wanted to make sure I had not come to the wrong conclusion.

No worries. I just re read my post and see where your confusion was. What I meant was the column at the ends of the beam will be in the middle of the garage at the wall/doors not in the centre of the garage

[2Gunz]

My guess is that this is going to real expensive real fast.  Steel isnt cheap.

If it where me I would go to the local supplier and tell them roughly what you want to do.
Im sure somebody will know in the ballpark of what size and thickness you will need.

Once you see in the ballpark how much it will be and if you still want to do it.... you then can figure out the details.

[resq302]

Granted, this is your garage and you can do what you want but if it were me, I would prefer to have a little extra space in between the cars in order to open doors, work on the cars, move around without bumping into them, storing extra parts or a jack, etc.

[elacruze]

I agree, you need a professional engineer or an architect to help you determine the size of the beam you need. When I built my garage I didn't want columns in my way either, so I had an engineer calculate what size I-beams I had to use based on the rest of the building design.

+1

I had a couple weeks of haggling between my architect and the building department which ended up with professional engineers, just to calculate the beam above my 18' garage door, which is incorporating the existing carport into the new construction; the corner roof support is being taken out as you want to do, so the roof load is higher than it would be with all new construction. After seeing all the concerns, it was obvious that it needed more than a guess. However, we ended up with a concrete beam rather than steel, so there was still room for further strengthening.