Header size estimate

[K13]

Just look for some opinions on the size of door header I might require for an addition to my garage. I am just trying to get an idea of what I am going to need so that I can get a rough cost of the project to see if I am going to proceed.

I currently have a 24'x 24' garage 2"x4' construction. My plan is to add a 12'x 14' addition off of the side to make the garage an L shape. What I am wondering is what size beam/header will I need to span the 12' opening in the side of my existing garage to carry the weight of the roof so that I can open it up to the 12' x 14' addition.

The addition will be on the back half of the garage and I plan on using a garage package and modiflying it for my needs .

Thanks in advance for any help.

 

[1969]

Glulam, steel I beam, you can make a beam from 3/4" plywood glued and screwed to do the job. Probably about 12" in height, breaking the joints about 2' apart. Someone here might have a code book to give you the specs, exactly.

 

[tcianci]

2 Things to look at. If you tear up the existing roof and frame the intersection of the 2 roofs as a true valley rafter system, you do not need any header as all of the roof load will be transferred to the outside walls. If you plan on leaving the existing roof, then yes you will need a header. Go to any real lumber yard that sells engineered lumber, they will have software from the engineered lumber manufacturer and size the correct beam for free. You need only to supply them with the span and the construction detail.

 

[willymakeit]

2 2x12 with 1/2 plywood between them. if it is a 3 1/2'' wall. Use #2 yellow pine as the structral properties are higher. This can be built in place, easier if your working by yourself. There is nothing wrong with gluelams either as mentioned.

 

[Torque1st]

Do you know anyone that is a good carpenter? If you do, have them come take a look and give you some advice. Payment for the advice is negotiable. If you live in an area with building codes you may need an Architect for anything structural.

 

[K13]

Thanks guys. As I mentioned I am only looking to get an idea of what will be required so I can estimate a price before proceeding. I will definitley seek professional advise before actually tackling the project.

 

[Kevin54]

It all depends on the way the trusses now run. Like tciani stated, the outer walls may be bearing the weight. Notice the pic posted. If your trusses run towards the addition you will bneed a header to support the ends of the existing trusses. If your trusses run towards the outer walls then the walls will support the weight and you will not need a header.

 

[K13]

It all depends on the way the trusses now run. Like tciani stated, the outer walls may be bearing the weight. Notice the pic posted. If your trusses run towards the addition you will bneed a header to support the ends of the existing trusses. If your trusses run towards the outer walls then the walls will support the weight and you will not need a header.

Thanks for the pictures! It is like your first example. I knew I needed a header just not sure of the size required.

 

[Kevin54]

Like posted above....either glulam or (2) 2x12's with a 1/2" spacer between.

 

[Justanoldguy]

A rule of thumb is 1 inch of beam depth for each foot of opening.
Thickness would be framing width.
In your case 4 inches.

 

[K13]

Perfect. Thanks guys much appreciated.

 

[rod725020]

If you are just carrying the roof load and your rafters span is less than 14', then (2) 2x12's for the header should be fine.

 

[1500hd]

If your running the new trusses square to the old trusses/rafters just use a double girder truss to support the tails. This way you won't have anything below the ceiling. This is how I did my addition to my garage.