How do I select a Header/Beam in my house?

Question

I want to remove the 2" x 4" wood supports between my enclosed Patio & Living Room on the first floor. It is a two storey house with 2" x 10" floor joists running parallel (at 16" center) to the wall in question. The roof is a HIP roof. The width at the new columns, the new beam will rest on is 17'-6". I would like to use a sandwich beam with a 1/2" x 9 1/2" steel Flitch plates with 2" x 10" wood on either side. I could use 2 such beams or more. The depth of the house is 25' plus another 8' for the patio, with the total width at 22'. The height of the house is 18' with another 6' to the top of the roof.

Answer 1

How about an engineered beam? Not the ones made from OSB but a laminated beam made from 2 x 4s glued together face to face with a built- in crown. They are used a lot in church construction.

Answer 2

On hip roof construction you have load on all 4 exterior walls. On a gable roof - the main load is on the longer exterior walls and the gable end walls have much of their load reduced because the Roof rafters or trusses are transferring that load to the outside (longer walls).

I would remove some of the interior drywall or whatever is on the inside of your walls, do this right where your new header will be going. Take out about a 2' wide pc. from the ceiling down about 1'.

The distance from your floor to the bottom of the header should be about 82" to match your window/door header height.

When you remove this section of drywall see how high the bottom of your doubled wall plates are and calculate the distance from the bottom of your double plate to a mark on the wall at 82" up from the floor. This is the maximum space in height that you have for your new header. I would use an "LVL" header 2 ply. This is *laminated veneer lumber" and it comes in various lengths and the thickness is 1-3/4".

We use 2 layers of these headers which equals a 2" x 4" wall thickness.You can install these one at a time and then glue and bolt them together.They must be one piece - no splices in the span.

The biggest problem you have is making sure each end of this header has at least 2 studs under it. And you also need to insure that you have adequate support under your bottom plates all the way down to your foundation in the crawl space or basement. Most houses have a rim board around the floor joist, but it is just 1-1/2" thick.You need to place a chunk of 4" x 4" from under your subfloor down to the Sill Plate right where these doubled 2" x 4"s are at each end of this beam.

You are transferring a lot of overhead weight down on this header and then the header transfers this weight to each end.

Another problem you have is that if your ceiling joist in this room run parallel to your new header, you have nothing to brace up temporarily while you install this new header. If the ceiling joist ran perpendicular to your header you could install a temporary wall about 2' out from the wall to support the weight while you install this header.There is a lot of weight up above this header location and you can't just expect it to hang unsupported while you put your new header in.

I would have a Contractor do this for you. It's just too much to try to explain, but I hope you have this one done by a Pro.