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We have a post in our living/dining room that is inconveniently placed that we would like to move a few feet. One structural engineer briefly glanced at it and said that we could move it, but I am wondering what this community of engineers thinks.

The house is a two-story with a flat roof. No attic.

The post is supporting a continuous 4x14 beam that spans the entire 24 feet width of our home. There are 4 4x4's holding it up. 3 of the 4 4x4's have footings underneath them (as can be seen in the foundation plan.)

The original structural engineer stated the following when asked about moving the post:

"Yes, if that beam is continuous, they haven’t really changed the beam loading by much by making that move.

The footing they will need is 2.5’x2.5’x12” Put some bars in it, (2) #4 each way on the bottom (3” clr)."

Plan of Relocation of Post

Bottom Floor Blueprint

2nd Floor Blueprint

Foundation Plan Showing 3 Footings Under 4x14 Beam

Actual photo of beam and post

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  • $\begingroup$ So did you check if the beam was continuous? That is a conditional statement,.. $\endgroup$
    – Solar Mike
    Oct 18, 2022 at 17:51
  • $\begingroup$ Yes the beam is continuous. The bottom of the beam is visible and so we can verify that it continuous. $\endgroup$ Oct 18, 2022 at 18:18
  • $\begingroup$ get a structural engineer to do more than briefly glance at it and pay them for the service, they may not be so cavalier about it. This group of engineer generally recommends you get a local professional who is licensed and bonded if the advice goes wrong. $\endgroup$
    – Tiger Guy
    Oct 18, 2022 at 22:46
  • $\begingroup$ I will do just that in order to go through the permit process but with a young family on a tight budget we can't afford to pay $500+ only to have a structural engineer to tell us that it is not a feasible idea, hence this post. Thank you in advance for anyone that can help. $\endgroup$ Oct 19, 2022 at 2:26
  • $\begingroup$ My original structural engineering boss used to say "We can do almost anything, cost will be the limiting factor." $\endgroup$
    – Forward Ed
    Oct 20, 2022 at 0:56

2 Answers 2

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You definitely need a local engineer to run some calculations on this to determine floor loading conditions.

Generally speaking engineers like to keep columns lined up from one floor to another. It helps eliminate a big point load in a beam. So if you move your ground floor column you should usually move the column above it as well. If not, your beam may need some additional reinforcing.

So its been a long time since I have had to read building drawings, but I get a sense that the joist on the far side of the beam run perpendicular to the beam. The floor joist on the side the photo was taken run parallel to the beam.

In the original drawing there is a beam that should be running perpendicular to the beam supported by the post you want to move. I do not know if that beam is tucked up in the ceiling space or has been removed and not replaced. (note the big dark square above the post). According to the original drawing this perpendicular beam is a load bearing beam that supports all the joist above the photographers head as well as all the joist on the other it. This beam represents a significant point load for your post. In the original design it is either on your post or very near to it. When you move your post this will change the loading condition on the beam the post is supporting.

You plans call for the wall in the kitchen to be removed and something about a beam above it. Whatever your plan is for this wall beam in the kitchen and all the way to the post, make sure you have an engineer or architect look at that before you go removing.

As an engineer I would want to be doing some number crunching with final desired support system to see how things changed. You want a local engineer because they will be familiar with your local building code and design loads up need to consider.

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I'm assuming that continuous beam is concrete (ignore my answer if it's timber) - we can't tell you much either way without looking at the beam reinforcement drawings. Your structural engineer's note about continuity holds good only if top reinforcement and shear reinforcement is continuous across the entire beam. If rebars across the top are not continuous, or if there's a huge variation in shear rebars, an engineer will need to re-run calculations, and there's a chance you won't be able to move the post without the beam getting cracked at the top.

Also, deflections will increase on the beam side that will grow larger in span. That whole beam seems to be supporting bathroom flooring above, and bathroom tiles require a nice levelled floor (not counting sloping) before they can be put in. If you've already tiled the floor above, then moving that post might not be a good idea because the increased deflection can crack those tiles.

Conversely, if the tiles aren't there yet but the deflection increases such that you need to add more screed to properly level the floor above, you'll actually end up loading that side of the beam more due to extra screed weight - though looking at the size of your bathrooms I don't think this will be a big issue. Again, this needs looking at the reinforcement

TL,DR - if it's a concrete beam, show us the reinforcing :)

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  • $\begingroup$ The beam is wood. Only the footing would be reinforced concrete $\endgroup$
    – Forward Ed
    Oct 20, 2022 at 1:19

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