I just purchased a home with a 1 1/2 car garage. The width of the garage door is really tight. The garage is brick.

Any suggestions on how I can just widen the opening?

Eveything else is great.

Tear out a wider rough opening and install a continuos header from each side. A two car garage is usually 16' wide. The header will probably need to be a 4X14 beam.

You Looking At A lot Of Money To Do This, One The Beam You Need Is Going To Cost You. It Would Most Likely Be A Double Microlam. You'll Be Tearing Out Sheetrock And Building A Temp Wall Support, If Not The Brick On The Outside Will Crack, And Even If You Do Support This Load It May Crack Anyway, If It Does You'll Be Replacing The Whole Front Of The Garage, Not Just What Is Cracked,

Im Not Saying It Can't Be Done, Its Just Not Worth It,
Here's My Guess On A Price To Do This , I Just Figured At Least 7800 And I Figured It Really Fast , But That's To Tear It Out And Reframe It, A New Garage Door, Fix The Brick, Rewrap The Metal Around The Gargage Door, Patch The Concrete, Tear Out The Garge Door Track,

Good Luck Man

A metal I-beam would be better that a wooden beam, you could take a drawing to a metal distributor and he would figure the load for you and tell you what size beam that you might need.

What are the interior dimensions of your garage? Twenty feet wide is a good measurement, it will alow you to park two cars and still have room to walk around the cars.

Letmetellu's suggestion is a good one but... depending on where you live and the municipal codes that apply for construction in your area... Normally (well "normal" for Southern California... a place where not many things are normal) you are supposed to apply for, pay for and have a "remodel" like yours, built after you have received a building permit... which may also involve approval from the local planning/zoning department before you can apply for the permit to build it (they all want to have a chance to adjust your property taxes upward to "reflect" the increased value of your home).

Different rules may apply if the garage is detached from the house.

The reason I'm rambling on about permits is: making the change in the garage without a permit may: 1) void your homeowner's insurance coverage for the garage... and maybe even cause fundamental changes in the coverage for the whole structure. 2) changes made without a permit may actually reduce the value of your property when and if you plan to sell it, because you will probably be required (by law) to disclose the "un-permitted" changes/modifications and that might conceivably complicate the escrow process if you are required to pull a building permit retroactively. 3) If the garage is attached to the house and you deviate from the standard uniform building code(s) by not having a licensed civil or structural engineer provide wind, snow and seismic load calculations and specify the size and type of header beam that the calcs apply to... you might... when you least expect it... be cited by the local building and safety folks (that could even happen during any future change of ownership/sale) and God forbid... the un-permitted and un-engineered header turns out to be inadequate... you'll have to do it all over again.

Sorry to complicate things here but, as a contractor, it is incumbent on me to provide structurally sound and well-built structures... and usually "over-engineered" to insure the safety of my customers and the integrity of the structure. Wouldn't want the garage wall or roof to come crashing down on that new Mercedes.

Good luck.