# Finishing basement (jackpost question)



## silky (Apr 22, 2009)

Hey guys/gals,

I am working on my cottage, finishing the basement, and have a question about the main beam and it's supprots. 

First off, it's a rectangular structure, about 25 x 30. The main beam is about 30 feet long, is made of 8 laminated 2x10's and is supported by inproper temporary jack posts. In my design one quarter of the space is a closed in laundry room, the rest is an L-shaped room. My problem is that one of these jackposts is in the middle of the L part and blocks the flow of the room. I have some pics if it's not exactly clear.

Is there a set code that states how many supports the beam needs, or how many feet a support is needed? This first jackpost I wish to remove is 5 feet in from the wall, the second is about 5 feet from that and the third about 10 feet from the 2nd (i only want to remove the first one!). I think I have heard that codes require a vertical support every 12 feet or something. Is this accurate or do I really need to call a structural engineer? 

note: most of the weight of the structure is on the other side. The kitchen/bathroom/loft are all on the other side. would this make a difference? Is there any way of supporting a beam without having vertical poles?

2nd note: Most of the beam is already further supported. 20 feet of the beam or so is supported by the wall for the laundry room which is made of 2x8's 16 inch on center. Im guessing that adds to the rigidity of the structure.

I have pics if it helps!

thanks much,
john


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## Aggie67 (Dec 20, 2008)

Sounds like a fun project!

Yes, you should call an engineer. What you see as a temporary jack post could be the builder's version of a cheap permanent jack post that is supposed to be there. I also question why a builder in his right mind would 1) install a temporary jack post to begin with, and 2) leave it behind on the job site. 

Besides, when you go for your permit, the town will probably want to see a drawing from an engineer showing the required structural changes to the beam that allow for the removal of the posts.


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## silky (Apr 22, 2009)

It has been a fun project, just a lot of work. This is the first I have ever tried of this type of work and I learned everything from books and tv shows For tricky bits I called in tradesmen but the majority of the work I did myself. Being inexperienced I have run into a few problems I don't know how to fix. ie. a few studs bowed out, th celing joists are not level, how to trim the outside door....but my builder friends are going to help with that over the summer.

I dont even think the township knows of these jackposts. Well, they may but I am sure it's not to code. They didn't seem to do a very throught inspectionk. For instance, they passed the house as complete with a 3" drain - septic tank and code calls for 4".... I can't be sure if they are the right kind or not, but all they are, are hollow metal tubes with holes that thick metal pins fit through. I can't see them as being designed to be permenant. I have a friend who is a contractor and he is going to search his code book for the proper spacing for beam supports and get back to me. From most of the builder friends I have talked to, the consensus is that the support is not needed since it is 5 feet from the wall and the next one is only 10 feet from the wall. But ya, I wouldn't anything without a structural engineer, although they are probably difficult to come by in cottage country! 

thanks,
John


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## Aggie67 (Dec 20, 2008)

You described a jack post. It occurred to me that at some point someone may have put a column in treat a floor flexing problem, in which case I question if a proper footing is under that column.

You should call an engineer.


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## silky (Apr 22, 2009)

I can say that the jackposts sit on the floor and are not concreted into the floor if that helps? 

Looking at it the placement of the jackposts it looks like they were just thrown in to support the beam when the structure was being framed. There is no rhime nor reason to their placement....they are closer together where there is less load.


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## JCAHILL4 (Nov 3, 2008)

*Need for pics and an S.E.*

Pics are always good. But I agree you need an engineer


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## silky (Apr 22, 2009)

I will get some pics up. Maybe I will scan a floorplan drawing or something and scan it if that helps.


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## ponch37300 (Nov 27, 2007)

Are all the posts the same looking or is this one different? I don't think there is any "12 foot" distance for post spacing, think it depends on size of beam and weight the beam is supporting. As mentioned above the posts need a proper footing under them and not just set on the concrete floor slab. You said you are going to scan a floor plan, do you have the original plans and if so do they have a structural plan that says how many posts there should be and where they need to be?


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## Michael Thomas (Jan 27, 2008)




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## silky (Apr 22, 2009)

ponch37300 said:


> Are all the posts the same looking or is this one different? I don't think there is any "12 foot" distance for post spacing, think it depends on size of beam and weight the beam is supporting. As mentioned above the posts need a proper footing under them and not just set on the concrete floor slab. You said you are going to scan a floor plan, do you have the original plans and if so do they have a structural plan that says how many posts there should be and where they need to be?


I will get the pics and what not up soon. I have final exams this week so I won't have time. 

I do not have the original floor plans. I may be able to get them, but there were disputes with the builder so it might not be possible. By floor plan I meant I could draft the dimensions and what not of the room, beam and joists etc. 

I don't remember but I am pretty sure they jackposts sit on the concrete/not in it. They are all the same looking...as far as i remember they are red poles with holes in them to slid a locking pin in. I am not sure if they screw or not. 

I am not so worried about the other posts because of the added support I havve build in. I seperated the laundry down the beam. The laundry room is framed with 2x8's 16" on center... I am sure the beam is pleanty well supported in that area! Plus the cottage is about 15 years old and there ae no signs of cracked walls or anything which would stem from settling.

thanks!

oh I think the beam is like 5 2x8's laminated but it could be 2x10's i forget.


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## Aggie67 (Dec 20, 2008)

Silky, I may have missed it in the thread, but when you say you framed a wall out under the beam, that doesn't really count as a load bearing wall, because there's no footing under it. Unless you put one in and I missed it here.

What disputes were there with the builder? Where there is smoke, there's fire.

Also, when I set posts, it's based on my engineering, not the code book.


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## Daniel Holzman (Mar 10, 2009)

There are many different building codes in use in the United States, however no code that I have ever used would specify the spacing of support columns for a main beam. As previously noted, the required spacing and design of the supports depends on the geometry of the house, which in turn determines the load on each post (as well as the load on the main beam). Anyone who purports to "look up in a code book" the required spacing and design of the supports is dangerous, in my opinion. You need a structural engineer.


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