Hot Topics: When is an Unsupported Beam a Good Thing?

A beam, badly placed above a window.

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Original Post: How to support an unsupported support beam??

CJMcc Member

I bought a fixer-upper that turns out to have a sagging ceiling support beam. So my question is how to support this support beam. Connected to that is a question of the flooring. See the photos, but here's the problem:

See that support beam on the ceiling? The one that exits the wall overtop of the big window? There's no support for that support beam!!! The window is now bowed down, there. The window's left slider is difficult to move. You can see it easier on the external photo. In addition, hard to see in the photo, but the siding planks are bulging outward, above the window there -- presumably also because the whole ceiling/roof is sagging down, because the weight on that beam is not supported.

Hot Topics, When is an Unsupported Beam a Good Thing

So, my thought is to add a support column -- which should be placed a few feet inside, and thus will rest on top of that concrete floor. It will look odd -- but it will provide the needed support. I can probably build a little bench between the column and the windowsill, and make it a little bit functional, at least. But looks aren't the most important thing; it's the need to support that beam so the ceiling doesn't continue to sag down.

Now, the contractor that I have doing some other things on the house is planning to put in a simple wooden beam (a 4x6) as the pillar. But he's the sort of guy who "just does it" and I don't really trust him to know the side-effects of a job like this. He'll just jack up the horizontal beam a bit and put in the supporting pillar. But is that the right approach? And what kind of footing should the pillar have?

That gets us to the flooring context. The floor is cement slab on dirt. (This room used to be the garage, at some point in the past. The initial house is 1938, but obviously expanded over time. The rest of the house has a crawlspace. This room's floor is almost 12" lower than the rest of the house.) Clearly, it used to have tiles on it. It was dog-urined carpet when I got here. I also am struggling to know what to do with the floor itself. Having asked everyone I know or can find, my best plan is:

1. Seal the floor against moisture with RedGard or some so-far-unknown-name of "self-leveling epoxy." Note that the house is located near the beach in Washington state; we get 11 inches of rain per month, Nov-Jan, before it backs down to only 8 inches or so. So I'm especially concerned about moisture wicking up thru the cement floor. I'm also concerned to seal in dog urine smells (though I will treat it before sealing it).

2. Insulate the floor somehow -- build a frame on top, perhaps even 2x4s, with insulation in the gap. It would still need ventilation in this tiny "crawl-space", I'm told.

3. Put plywood on top

4. Put carpet on top

So in the end, I'm not sure how the needed support pillar will play in to the flooring question. Maybe just a wooden support pillar, but on a concrete post base (?), on top of a moisture barrier of some kind, on top of the existing concrete floor?

Whew. Well, that's a lot for one post. But the main question is what's right to do for the support pillar?

Thanks for any tips, advice, or even vague thoughts!


Highlights from the Thread

chandler Forum Topic Moderator

Welcome to the forums! Not sure who the numbnut was that put that beam on top of a window, but that's water over the bridge, so to speak. It must be supported secondarily. The concrete may not be substantial enough for the weight. Normally you would cut a square hole in the existing concrete, dig down to at least 12 inches or below your frost line and pour concrete grout which is harder than concrete. You basically will be pouring a footing for the post. Jack up the beam carefully and measure/cut for a post, at least 6x6, sitting it on your new footing. You can decorate it later. The decorative wood on the underside of the beam may need cutting out so your new post will bear on the beam itself, rather than on 1x lumber laid flat.

joecaption1 Member

In love with that window? Another way but a lot more work, but will look a whole lot better when done, would be to remove that window, and build your support beam into the wall all the way down to the bottom plate.

Then reframe the wall for two windows on either side of where the beam is.
Looks like your siding’s in poor shape anyway so not a lot to lose.

CJMcc Member

Thanks for both the explanations and ideas. Very helpful.

For the first point, about sinking a concrete grout footing -- I see. That was something that never occurred to me. The other beams (to left and right of the problem beam) are supported within the wall, and they rest on what I assume is the same strength of concrete slab. Or... I don't know these things... would you expect the concrete at the edge to have been sunk deeper than in the interior of the room/garage?

BTW, the frost line -- being fairly far north, it does freeze here and gets snow; however, it's right at the coast, so it usually doesn't get very cold. I don't know what I'm talking about, but would be surprised if the soil beneath the house freezes, during a normal winter.

The overhead support beam is itself only 3.5 inches wide and 9 inches tall. So I'm guessing that a 4-by-X pillar is as good as a 6-by-X, isn't it?

Something in the photo must look otherwise, but it has no decorative wood; unless I'm missing something (always possible; I'm very inexperienced in this).

Meanwhile, the idea about taking out the window and reframing... that certainly deserves consideration. Come to think of it, that's what the contractor initially suggested. I had forgotten. At the time, I thought it would be much better and cheaper to put in a support pillar, even if it is odd looking. But if that's going to need sinking a new footing down through the existing concrete floor -- well, that might change the equation. Maybe it wouldn't be so bad. A shame to lose the big window, but not the end of the world.

Thanks again for the quick feedback! This is great and most helpful indeed. And not wanting to cut off more ideas, I'll close by assuring all that I'm happy to get further ideas/discussion!

marksr Forum Topic Moderator

A support post needs a better footer than a long wall - the load is transferred to a small area versus being supported by the length of the wall. Footers are always dug down below the frost line. The frost line is the depth that that the ground is expected to freeze down to during the most extreme winter for that location.

CJMcc Member

Oh dear. These comments have led me to question the stability of the other support beams, as well.

I went outside just now and dug down along the foundation, to see how far down the concrete went. It, ummm, didn't take me very long. Here's a photo of what is directly underneath the "non-problem" support beam, to the right side of the window. I put a red box around the bottom edge of the concrete. It's about 6" below the bottom siding plank. So... not going down real deep.

Re: the frost line, the lowest recorded temp was apparently 4 degrees F, in Feb 1989. That's extremely unusual, being walking distance to the Pacific Ocean. But it can happen. No doubt the ground froze a ways down, that year.

So all in all, this begins to sound like a rather larger task. As in, putting in a new, proper foundation for a whole section (or all?) of the house. Yoiks. Or am I getting carried away?

The general history of the house:
+cabin built in 1938 (nice tall crawlspace)
+garage probably not original, so added 19__. Originally had flat roof (the- wuh-??? Seriously? A flat roof, where you get 12 inches of rain per month?? Oy vey.)
+3 rooms added, 19__? (short crawlspace)
+garage converted to living room: 19__?
+sloped roof added atop still-existing flat roof, I think prior to 1980. Extra weight added to those beams.


PS: After sleeping on it, I realized the contractor's original suggestion was different. Not replacing the window. Instead, he suggested adding a header beam all the way across the top of the window, supported then by the pillars on either side. Downsizing the window, as y'all have suggested, seems like a better option, so far as that one beam goes.

Handyone Forum Topic Moderator

I'm a party pooper. I see nothing good about this room.

My best guess it that this wasn't a garage, but a patio cover or an attempt at an enclosed patio cover. I also believe someone added this window at some point with no idea what they were doing. They cut into structural members.

I would advise against the post idea. You really have no place to put a post. It can't go near the window, so that would leave it in the middle of the room.

I would open up the drywall a couple of feet on either side of window (floor to ceiling). Post back pictures of open wall, and then get you can get some ideas on how to place a header above window that would support roof (no sagging), and beam in question.

CJMcc Member

The driveway used to come right up to the house, at that point. That doesn't *guarantee* that it was a garage... but it seems quite likely. But it is odd, because where was the garage door? It seems it must be where the window now is. So... where was the structural support, at that time? Must have been the same problem, it would seem.

Things certainly don't add up.

However, it is (as the previous reply said) water over the bridge, now.

BTW, it's not drywall. Rather, it is a thin plywood -- 0.25 inch.

BridgeMan45 Member

It's also possible the garage door header was removed by some klutz to enable installing a taller window. Your excavation photo indicates a simple garage slab floor, with no footing--quite normal in many parts of the country having shallow frost depths. If it was mine, I'd retrofit a deeper (12"+/-), continuous reinforced concrete footing along the entire length of wall presently lacking one. Fairly simple job, actually, as all of the work could be done from the exterior. Hardest part would be to provide egress for any air trapped between the fresh head of concrete and the underside of the existing slab; otherwise, the air will prevent fluid concrete from filling the void between the vertical soil face and the underside of the slab. Some temporary interior supports would also be needed to prevent the ceiling loads from causing the wall/slab to sag once the soil under the slab is removed. I'd go with two new, smaller windows, with a column between them supporting proper headers over each (for the windows and that naughty beam).

CJMcc Member

Ugh. The more I look at it, the worse it gets.

I now notice that the ceiling beams are bowed in the middle. The one to the right of the window is bowed about 0.25 inch (in a 4-foot run, in the middle). The beam over the window is also bowed, but less so.

Those beams are 15 feet from wall to wall (another couple feet outside, and little if any further inside the back wall [not in the pictures]). They are 3.5 inches wide, 9 inches tall, single piece solid wood.

So, whaddya think? Do I need to actually put two support pillars (one for each beam) in quite literally the middle of the room? From previous postings, I suppose that would mean cutting thru the cement floor and sinking some better footings for the pillars.

PS: Curiously, there are already 2 holes in the floor, now filled with sand. They contain now-terminated electrical wiring. They are off-center, but one of them is close enough that it could be incorporated into a new cut, if I wanted to for some reason. BTW, on the defunct electric panel, there are 2 slots labeled "Trailer." Maybe they're related, but it seems unlikely, because the cuts in the floor should be newer than the ancient electric panel. I feel like an archaeologist!

marksr Forum Topic Moderator

I hate to say it but you'll probably be best off hiring an engineer to evaluate and come up with a plan to implement.

Handyone Forum Topic Moderator

Forget about support posts in room. Follow BridgeMan's advice. You also have a contractor on hand for additional input.

Simply put, the wall where window is now needs to be rebuilt, not a big deal. It also needs footings added, which is a little harder but can be done.

Once you have a plan to replace window wall, you can think about replacing the ceiling beams also.

CJMcc Member

Yeah, I suppose so. I think it comes down to the fact that this room & its problems will take a while to fix.

I'll probably have the current contractor do a temporary support pillar -- mainly because we've already agreed to a list of work items, and he is stingy on rebates! Probably will put a support OUTSIDE, which has its own problems. But will simplify fixing up the flooring itself, as there won't be a pillar in the middle!

Thanks much to all who commented!

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