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silky 07-06-2011 10:24 PM

help with main beam
 
Hey all,

I am in the process of finishing the basement at my cottage. We would like to remove a jack-post that is in a terrible position that would block most of the flow of the basement. Just looking for some advice on how to tackle this.

The cottage is about 27 x 21. Above the basement there is a main floor, above that there is half of a second floor. The second floor has a large open loft area. The beam is comprised of nominal 4 nominal 2x10's laminated together. There are jack-posts at 6 feet, 13 feet and about 20 feet. The beam is pocketed into the cinderblock. The area above the part of the beam I would like to remove is probably the lightest part of the structure. Above it is a living room and a bedroom and above that is the open loft area and a small sitting area. The washrooms and kitchen are all on the other side of the building.

Looking for some advice on how to safely go about removing the jack-post. Would any of these be viable options?:

1) remove jack-post and lag bolt the beam to increase the "lamination"

2) remove the whole section of beam...from the cinderblock to the second jack-post at 13 feet and replace the whole thing with something stronger. I would think this not a good option because the new beam would only have a few inches of bearing on the jack-post at 13 feet.

3) Remove the outside boards of the beam upto the 13foot second jackpost...so remove the bread from the sandwhich... and replace them with lvl boards laminated to the existing beam. So basically making a sandwhich with LVL boards as the bread.

4) flitch beam.


any other suggestions are appreciated!!!

note: I do have experienced people working with me. We will not simply cut the jackpost etc. Everything will suported so the building doesn't do the tumble down on our heads.

appreciation in advance!
john

AndyGump 07-06-2011 11:36 PM

First let me say that I am not trying to be a *rik here but do you really expect to get cogent and professional advice on this question from an internet forum?

A DIY internet forum?

Spend some money for an engineer.

Andy.

silky 07-06-2011 11:41 PM

Quote:

Originally Posted by AndyGump (Post 681196)
First let me say that I am not trying to be a *rik here but do you really expect to get cogent and professional advice on this question from an internet forum?

A DIY internet forum?

Spend some money for an engineer.

Andy.

Well, just because someone gives the advice doesn't mean I have to take it! Generally you can tell people who know what they are talking about form those who don't. Moreover, I am somewhat interested in hearing if it's atleast feasable before I go and pay an engineer to tell me it isn't. What questions am I supposed to ask here? How do you hammer in a screw?

AGWhitehouse 07-06-2011 11:48 PM

I think what Andy is saying is that determining the best way to re-arrange the structural foundation of a building involves a little more than an itemized paragraph. Plans, sections, dimensions, photographs, regional snow loadings, wind zone characteristics, and earthquake zone loadings are all areas of information that is needed to determine the correct beam loading. once the beam loading is determined then it can be designed to fit the spaces needs. This site is where you might pass a specific idea about a beam past others, but not figure out the whole design.

But to answer your question, no you don't hammer in a screw. You simply use a screwdriver (with matching head type of course) to twist it into the medium.

silky 07-07-2011 01:01 AM

I think this is getting over-complicated. I am not asking for spefics. I am asking if it is techincally possible to do what I want. I am not asking people to supply with me load calculations so I can run out with a sledge hammer and knock the post out. I am trying to find out if the methods I have described are acceptible and if not what the proper procedure would be.

Ron6519 07-07-2011 05:11 AM

Quote:

Originally Posted by AGWhitehouse (Post 681205)
But to answer your question, no you don't hammer in a screw. You simply use a screwdriver (with matching head type of course) to twist it into the medium.

And you turn it clockwise. Those of you with digital clocks are, well, screwed.
So to speak.

Daniel Holzman 07-07-2011 05:38 AM

Yes you need to hire an engineer to design the beam. But to answer your questions:

1. Using lag screws to "increase the laminations" will not increase the load capacity of the beam because you are not increasing either the moment of inertia of the beam or the modulus of elasticity of the beam. Cross this idea out.

2. Cannot tell from the description if you have a continuous beam or a beam in several pieces. You can potentially replace the entire beam (all 27 feet) with a stronger beam. If the beam is simply supported (i.e. discontinuous), you may be able to replace the middle section, that would be an engineer question.

3. LVL boards are typically not that much stronger than equivalently sized dimensional lumber, so you are not likely to gain adequate strength using this technique. This is a question for your engineer.

4. A flitch beam could probably be engineered to work, using steel plate on the outside of the wood. Design is a little bit tricky, due to the need to install the plates using an adequate number of fasteners to maintain horizontal shear flow. Your engineer will know how to do this.

There are other potentially more exotic techniques that could be considered by your engineer, including use of fiber reinforcing, or steel cables. Likely the simplest are the total replacement and construction of a flitch beam. In all cases, your engineer will verify the adequacy of the existing columns and bases, the method of attachment of the beam to the columns, and the beam pocket supports.

This is a reasonably complex job, so plan to pay somewhere north of $500, maybe more if you need detailed plans, specifications, and a stamped report for your building permit.

JoeLena 07-07-2011 06:41 AM

Got no advice, but want to thank Mr. Holzman. I'm sure his answer is what the OP wanted, instead of just the often generic "get an engineer", or the more common "what did the building inspector tell you?", he took the time to actually answer the question. So in the future someone else might gain from this thread. Excellent.

tcleve4911 07-07-2011 07:23 AM

2) remove the whole section of beam...from the cinderblock to the second jack-post at 13 feet and replace the whole thing with something stronger. I would think this not a good option because the new beam would only have a few inches of bearing on the jack-post at 13 feet.

This is the one I would lean towards....replacing the entire beam.
I would also replace the post to address the issue of having enough surface area for the beams to rest on.

Hope this helps.

silky 07-07-2011 10:05 AM

Quote:

Originally Posted by Daniel Holzman (Post 681254)
Yes you need to hire an engineer to design the beam. But to answer your questions:

1. Using lag screws to "increase the laminations" will not increase the load capacity of the beam because you are not increasing either the moment of inertia of the beam or the modulus of elasticity of the beam. Cross this idea out.

2. Cannot tell from the description if you have a continuous beam or a beam in several pieces. You can potentially replace the entire beam (all 27 feet) with a stronger beam. If the beam is simply supported (i.e. discontinuous), you may be able to replace the middle section, that would be an engineer question.

3. LVL boards are typically not that much stronger than equivalently sized dimensional lumber, so you are not likely to gain adequate strength using this technique. This is a question for your engineer.

4. A flitch beam could probably be engineered to work, using steel plate on the outside of the wood. Design is a little bit tricky, due to the need to install the plates using an adequate number of fasteners to maintain horizontal shear flow. Your engineer will know how to do this.

There are other potentially more exotic techniques that could be considered by your engineer, including use of fiber reinforcing, or steel cables. Likely the simplest are the total replacement and construction of a flitch beam. In all cases, your engineer will verify the adequacy of the existing columns and bases, the method of attachment of the beam to the columns, and the beam pocket supports.

This is a reasonably complex job, so plan to pay somewhere north of $500, maybe more if you need detailed plans, specifications, and a stamped report for your building permit.

Thank you!!!

Well I don't know what the term for the beam is called but it s not a continuous piece. So as I said the beam is made of 4 rows of laminated 2x10's. In each segment of beam there are 2 shorter pieces and 2 longer pieces. So it goes short piece (6ft) long piece (13ft) short piece (6ft) long piece (13 ft). So the jack-post is positioned under the seams where the shorter pieces end. I have an architect buddy who looked at it and didn't think there needed to be a jack-post 6 feet from the wall and thought the builder probably just used whatever wood he had lying around to build it. I have some pics that I will upload.

silky 07-07-2011 10:16 AM

3 Attachment(s)
So in the first pic you can see the two jackposts. The post closest, on the right, is the one at 13 feet. The farther is the one 6 feet from the cinderblock wall which is the post I would like to remove. The verticle pieces you see on the right side of the picture are apart of a wall built underneat the rest of the beam to seperate the laundry room.

The second and third pics show where the first jack-post (6foot one) sits on the beam. You can see the joint in the first layer of laminated beam in pic 2. Pic 3 is the reverse side of the beam from pic 2

silky 07-07-2011 10:27 AM

Quote:

Originally Posted by tcleve4911 (Post 681279)
2) remove the whole section of beam...from the cinderblock to the second jack-post at 13 feet and replace the whole thing with something stronger. I would think this not a good option because the new beam would only have a few inches of bearing on the jack-post at 13 feet.

This is the one I would lean towards....replacing the entire beam.
I would also replace the post to address the issue of having enough surface area for the beams to rest on.

Hope this helps.

I was hoping to not have to remove the entire beam if it is possible. The problem with changing posts is that the basement is essentially framed. Originally I was just framing it to insulate it to cut down on heating expenses and for the water system. Now I figure I might as well make a living space out of it which would almost double the living space. To change Jackposts I would have to cut out flooring and take down walls.

silky 07-08-2011 10:37 AM

would it be possible to replace the entire 13 foot section with an I-Beam or is it a bad idea to have two seperate beams?


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