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walkereng, Consultant
Category: Structural Engineering
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Experience:  Over 30 years of Structural Engineering experience.
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Replace 2X4 load bearing basement wall.Open span of 22.5 feet.

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Replace 2X4 load bearing basement wall.Open span of 22.5 feet. house width is 26 feet. Beam will support upper floor and roof. Standard shingle roof. 84 lumber says four 1.75 X 14 inch versa-lam panels mated together. I would prefer to use a 8 or 10 inch I-beam with the correct post/column at each end with proper concrete footings. Existing floor joist will be attached mechanically with curtis joist hangers. What are the proper 8 or 10 inch I-beam and column/post sizes.

walkereng :

I can help.

walkereng :

I have attached a file. Can you take a look at it and answer the questions at the bottom? This will help me answer your question.

walkereng :

I am on the East Coast, so it is getting close to 1:00 a.m., can you work up your answers to my questions and I can finish this up in the morning?

walkereng :

I will switch over to the Q&A format and the system will send you an e-mail. When you are ready to reply, just check your e-mail and reply to the latest one you get. You information will come back to me in an e-mail. Talk to you in the morning. Thanks

Customer: replied 5 years ago.

1. basement beam, span 22.5 feet. No post or column in middle, support at ends only.

2. The floor floor joists span is 26 feet, the widith of the house. They extend two feet over the cinder block basement walls.

3. Roof tresses are factory made. Not sure about the load distribution. The hallway wall on the upper floor is directley above the basement wall we want to remove. I would guess and say it does carry some of the roof load.

4. Pasadena, Maryland

5. Asphalt shingles

6. 2 story basement, upper floor,roof.

I really need to try and find out if any roof load or wall load is coming down from the 2nd floor and roof. This will make a huge difference in the beam size. If you have factory built trusses, they are generally designed to span from exterior wall to exterior wall without any intermediate support. You have a hallway on the 2nd floor above the basement wall, but do you also have a 1st floor wall above the basement wall? If I run the loading case with just 40 psf Live Load and 10 psf Dead Load only on the 1st floor, I get the same size quadruple laminated beam that was sized at 84 Lumber. If I add in 2nd floor load and roof load those laminated members do not work at all for the 22.5' span.

Can you look up in the attic to investigate the possible connections between the bottom chord of your trusses and the top of the 2nd floor hallway walls? Can you see if there are any vertical truss members right above the 2nd floor walls? Or maybe you can send me a picture or two from the trusses in the attic. Attach them with the paperclip in the toolbar of the chat window.
Customer: replied 5 years ago.
The house is only two levels basement and 1st floor.I have my son looking in the attic now. The tresses have the metal mending plates and are made out of 2X4 stock. The vertical supports do not align over top of any walls. The live load and dead load psf are exactly what the 84 lumber engineer used in his calulations.
You can use a W10x30 steel beam (50 ksi). This beam is 5.75" wide, 10.5" deep and weighs 30 pounds per linear foot.

You will need to have a solid mechanical connection between the floor joists and the top flange of the steel beam, for lateral support.

You can use a 30"x30" concrete footing that is 12" thick. Place 5 - #4 rebar in each direction, 3" up from the bottom of the footing.

You can use a Std. weight 3" diameter steel column A501 or A53 Grade B for your supports.
Customer: replied 5 years ago.

Is there any way we can use a W8 beam with the 50ksi? When we lay out the footings for the support posts do the posts need to be in the center? One end of beam will be next to the cynder block wall, so to be centered we would need the new footing to be tied into the existing foundation footing? At the other end the post will be next to an existing king stud, should we excavate under the existing concrete floor to get the footing centered next to the king stud? Can the footings be dug down deeper to reduce the size?

You could use a W8x40 steel beam (50 ksi). This beam is 8.125" wide, 8.25" deep and weighs 40 pounds per linear foot.

The center of the steel column posts can be 15" in from your the ends without a problem. That will make the post in the center of the new footings.
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Customer: replied 5 years ago.
We want to know if we could use a 12 inch diameter 4 foot tall concrete cason instead of the 30X30X12 inch footing.
Without a soil report, I do not recommend it.

The 12" diameter caisson end has an area of 113 square inches.
The 30" x 30" footing has an area of 900 square inches.
That is 8 time more bearing area than the caisson.

Piles/Caissons depend on end bearing and also skin friction. I do not feel you will be able to develop enough skin friction to equal the extra bearing resistance you will need.

The only way I could tell, would be if you had an actual soil investigation that gave me the design parameters based on the actual soil you have onside.

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