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Discussion Starter · #1 ·
Where would I find metal shims, to shim posts/beams? I've been cutting shims from a 4x4, but I think metal might be better if the cost is not too great. I couldn't find any at HD, but I wasn't looking very hard.

Thanks!

Vince
 

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Steel supply or a welding shop should be able to cut you whatever you want. If on PT wood, they need to be galvanized or stainless. Any way to get plastic in there? You can buy various kinds of "plastic" in various thicknesses, too. Plywood won't work?
 

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Discussion Starter · #3 ·
I just thought you could buy a pack of steel shims somewhere. I need to shim between some joists and a new beam I put in. The sag near the center is like 1/4" from the bottom of the joist.

I thought steel would hold up better by not compressing under load? I'm no pro. I had cut some from douglas fir (just taking a slice out of the leftover 4x4 I used as posts) but thought that if steel were cheap/easy that it might be better somehow! I may just be over thinking this.
 

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I just thought you could buy a pack of steel shims somewhere. I need to shim between some joists and a new beam I put in. The sag near the center is like 1/4" from the bottom of the joist.

I thought steel would hold up better by not compressing under load? I'm no pro. I had cut some from douglas fir (just taking a slice out of the leftover 4x4 I used as posts) but thought that if steel were cheap/easy that it might be better somehow! I may just be over thinking this.
would body shims or suspension shims from an auto parts store work for what you are trying to accomplish.
 

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Look in the roofing section---Menards has packets if galvanized steel squares that I use to shim bath tubs.
 
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Too Short? Cut it Again!
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Shimming a sagging beam, assuming it is not decorative, with any sort of shims kind of scares me. What is or will be on top of all this? Of course the lumber could be warped that much I suppose if the gap is at the center. I would have picked a piece of straight lumber but if it was crowned? I would put it down crown up. If I saw a 1/4 inch gap though? I would probably chalk it up to aging and not sighting the lumber. I would pull it out and get a new one. How long is this beam and what are the joist dimensions?

A sheet metal shop, if you give them a few days, will make you folded over wedge things that will conform out of steel or whatever you want. I just don't get how you think metal better than wood shims?

To be honest, if this is new construction? I would get some jacks to support the beam and cut out the support member and fit a new member cut to the proper size. Or if you cannot, still jack it up and slip a solid steel plate in there or something (Mickey Mouse construction thinking I know).

You cannot "shim" a quarter inch gap between structural members unless you slip the inspector cash, a hotel key, expensive scotch and cheap hula dancing hooker from whatever convention is in town.

Whatever path you take? Know that shimmed, that 1/4 inch will grow in dimension over the years and come to haunt you.
 

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You cannot "shim" a quarter inch gap between structural members unless you slip the inspector cash, a hotel key, expensive scotch and cheap hula dancing hooker from whatever convention is in town.


:laughing::laughing::laughing:---Thank you--I needed a laugh.---Mike---
 

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Discussion Starter · #8 ·
I just put the beam in. It's 4x8, supported with 4x4's that are 6 feet apart (I should have probably made it 4 feet apart. It's purpose is to reinforce the floor in anticipation of an aquarium that will be placed between the beam and the foundation wall on the floor above. The joist span that the aquarium will sit on is 4 feet. ie; the main house beam is 10 or 11 feet from the wall. I added this beam 4 feet from the wall and the aquarium will sit above it between beam and wall.

I actually flipped the beam around and it was still "sagging". I thought ... oops, I have the crown side down, I'll flip it and ... same thing.

I'm thinking that the beam is not warped, and I'll check it with a laser level later, but get this...The beam spans about 6 joists or so. The first joist has a gap of 1/8", the second joist is almost above the post and it's snug up against the beam, the third joist gaps at 1/8", the fourth 1/4", the fifth is 1/8", the sixth is snug up and is somewhat above the post. In retrospect, I did a terrible job of planning the posts out, as I should have spaced them better around the joists, but it is what it is.

So ...what's up with the first joist being 1/8" then the second being snug, then the thirst being 1/8"? I'll take a picture. If it were sagging in the middle, I would assume that the first joist would be snug as the beam bends.

I should have checked for straightness better.

In anycase, the beam is there for extra support to prevent the floor from sagging under a 2000 lb or more aquarium, it's not in there to correct any current problem.

Vince
 

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Discussion Starter · #9 · (Edited)
OK, I crawled back down there and I took some pics and also I used a laser level and checked...the top of the beam is STRAIGHT. So it's the wanky joists. I should point out that this house was built in 1939, so maybe things are a bit weirder down there wrt consistent joist width? No, that doesn't make sense. I don't know what's going on, but the beam is pretty straight.

Let me see if I can attach a picture, or a link to pics here...ugh, well here are links to the pics, I'll see if I can figure out how to upload better

The laser sighted beam

https://picasaweb.google.com/lh/photo/gBlDndqBctLw66YCqO2neQ?feat=directlink

Full view of beam, note the wood shims I shoved in there

https://picasaweb.google.com/lh/photo/FYUEbIdgCNmNH_dTNqxZnw?feat=directlink

NOTES: I have not nailed the metal hardware to the wood yet and the metal straps from the preformed concrete piers are NOT perfectly perpendicular to the block, they are slanted. One post is shorter than the other, the ground is not level. The beam i mostly level, but I don't think it matters that much as it's snug up against those joists that do touch it.
 

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Looks good to hold the aquarium---I like steel shims better than wood for that application.
he wood will work.


I suspect that the builder had some highly crowned joists there!
 
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You cut the post short, jack the beam tight to the joist and shim or re-cut the post then secure the joist to the beam.

Are the post treated?
 

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You cut the post short, jack the beam tight to the joist and shim or re-cut the post then secure the joist to the beam.
My theory as expressed before also but I thought you had a gap between the posts and the beam somehow. No matter. Since this added support you might not need jacks but I would rent or borrow or couple to see how close you can get the top of the beam to those joist. Then measure carefully and cut your posts.

You can shim door frames, windows and other non-structural things to hold them in place. You really don't want to use them as a fix for gaps in structural support. Shims of any kind have no real structural integrity as far as supporting live loads and things. If you still have gaps of 1/4" I wouldn't use shims. I would have steel plates cut. Not angled shims.

Bless you for doing this by the way. You don't know how many fish enthusiasts I have encountered that just brought huge things home, filled them with water forgetting the weight and dead load, and wondered why they heard strange sounds like lumber screaming or nails pulling out of joist hangers at night.

And do check to make sure your joists are on hangers and not toe nailed as was still common practice in the 30s. It will be a pain but you don't want an aquarium resting on 16 or 20p nails.

And just out of curiosity, if the joists are just causing the gap because the lumber was crowned? How level is you finish floor above? What is the subfloor. How does placement of the aquarium impact it? The aquarium will sit crossing the joists, not parallel to them right?
 

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I would have no reservations about sliding a few steel shims in considering your situation. We use them regularily between steel or wood beams & the foundation. I cut all of our steel shims from 1/4" or 1/8" by 4-5" steel plate. I buy 20' lengths due to the amount we consume. You should be able to find something a tad smaller at a decent hardware store, and just need to cut them to length.
 

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You cannot "shim" a quarter inch gap between structural members unless you slip the inspector cash, a hotel key, expensive scotch and cheap hula dancing hooker from whatever convention is in town.


:laughing::laughing::laughing:---Thank you--I needed a laugh.---Mike---
Actually you can shim the beam with a ¼’’ metal shim we have done it many times but you have to weld the shim to the beam and post the building inspector will pass it. We have also seen people stack in excess of 7 or more metal shims in various thicknesses and then weld them all together and the inspector still passed it go figure.
 

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I am confused at this point. Like most of you I assumed the 1/4" gap was between the posts and the beam. If I see the problem from the pictures? The gaps are between the top of the beam and the bottom of the joists.

The beam has been determined to be level.

You would not propose to shim with wood, steel or whatever between all the spaces between joists and beam would you?

This beam and its posts are non load bearing at this point. Why not just bite the bullet and cut the posts a 1/4" taller? Jack up the beam even if it makes the other joist squeak a bit. And but the structure in place?

The guy plans to put a billion pounds of dead weighted water and fish (I love sushi from client aquariums) on this structure and at least realized he needs extra support. I really don't want him starting with a 1/4" gap although I will accept a steel plate, cut to size and anchored in place as a solution. I still don't know if I could get the scheme past an inspector though.

And if the ends of the joists are hanging only by 20p nails toenailed, typical of the era of the guys house, it is all potentially a rather academic argument?
 

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OK, I crawled back down there and I took some pics and also I used a laser level and checked...the top of the beam is STRAIGHT. So it's the wanky joists. I should point out that this house was built in 1939, so maybe things are a bit weirder down there wrt consistent joist width? No, that doesn't make sense. I don't know what's going on, but the beam is pretty straight.

Let me see if I can attach a picture, or a link to pics here...ugh, well here are links to the pics, I'll see if I can figure out how to upload better

The laser sighted beam

https://picasaweb.google.com/lh/photo/gBlDndqBctLw66YCqO2neQ?feat=directlink

Full view of beam, note the wood shims I shoved in there

https://picasaweb.google.com/lh/photo/FYUEbIdgCNmNH_dTNqxZnw?feat=directlink

NOTES: I have not nailed the metal hardware to the wood yet and the metal straps from the preformed concrete piers are NOT perfectly perpendicular to the block, they are slanted. One post is shorter than the other, the ground is not level. The beam i mostly level, but I don't think it matters that much as it's snug up against those joists that do touch it.
why not replace your post with new ones 1/4" longer. transfer your joist layout to the beam and notch the top of the beam to fit. the joist that are tight will need to be notched 1/4", the 1/8" gapped ones will need a 1/8" notch, the ones w/ the 1/4" gap will recieve no notches as they will be tight to the joist now. no shims needed now.
 

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Discussion Starter · #17 ·
Hi guys, first of all, thanks for all the suggestions and advice!

Now to clarify some things;

1) The joists are not toe nailed to a rim joist, they are sitting on a 2x6 (I think) sill plate, which is sitting on the foundation. There is blocking between the joists at the sill plate, so that end is firmly supported, I measured at least 6 inches sitting on the sill.

2) The the two joists that are above the posts are butted up tight against the beam, they sit squarely on it (joists 2 and 6)

3) joists 1, 3, and 5 have about a 1/8" gap to the beam, joist 4 is almost 1/4"

4) I measured the joists they are all 7 1/2" to 7 9/16" (hard to measure!)

5) The aquarium will sit perpendicular to the joists, so it's supported by the multiple joists, not just one or two

6) The gap is NOT between the post and the beam, as was pointed out. Sorry, this wasn't very clear in the first post. I had a heck of a time putting that beam up there by myself, it required milk crates and scrap wood! Lifiting an 8 foot piece of 4x8 in a crawlspace by yourself is not easy!

7) I tool a look at the main house beam and I can see that there is a gap between joist 4 and the beam as well! Joist 4 also appears to be tight to the subfloor, the other joists SEEM a bit less tight.

8) I took a straight 2x4 (checked it with my handy dandy laser level) and shoved it around down there, the bottoms of the joists in question are NOT IN LINE. I can't get any straight edge to span more than 3 adjacent joists without a gap.

9) The sub floor is solid wood, I'm guessing at least 1/2"`thick. It's 3 1/4" wide planks. On top of this sits the hardwood floor which is 3/4" thick oak (According to the guy who refinished it years ago, so it's not quite a full 3/4" after sanding down) The subfloor planks run perpendicular to the joists and the hardwood floor runs parrallel to the joists on top of that.

10) The joists are a bit rough looking, meaning they are not like what you'd see at Home Depot, they hare not sanded smooth or anything, I don't know if that just means that they are just bumpy and that might be why some joists are butted up tighter against the subfloor?

11) The floor above is fairly flat, it's not sagging at all. I poured some water on it and it pools, rather than runs in any direction.

OK, thanks for reading all of that!

My conclusion is that maybe some of the joists are slightly crowned up, with the biggest gapped joist being the most crowned up towards the subfloor.

The bottom line though is that ... there are gaps for whatever reason.

Some possible solutions as presented in this thread;

- Crank up that post and force the low joists up
- shim with wood
- shim with metal
- index and notch the beam with appropriate sized notches, then fit the beam back and all joists will sit in the beam notches. This would mean that I would notch 1/8", 1/4", 1/8", 0, 1/8", 1/4" so that the top of the beam meets the largest gapped joist and the currently ungapped joists will sit in 1/4" notches.

I really don't want to force that low joist up (nor will I notch the joist!) because the lathe and plaster walls might just decide to show me what they think of forcing them out of where they have settled in the past 70 years.

Shimming is easiest, but it seems to raise the most red flags with you guys. Metal would be preferred over wood.

Notching seems like a good solution as it is similar to shimming but without the stigma of shimming. This requires the most work as I have to uninstall the beam, cut new posts and notch the beam. However, if this is the best solution, that's what I'll do.

Thanks for reading this long winded post! And thanks for your advice, tell me what you think!

Vince
 

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Discussion Starter · #18 ·
You cut the post short, jack the beam tight to the joist and shim or re-cut the post then secure the joist to the beam.

Are the post treated?
The posts are NOT treated. I was going to spray some boracare on them after I got them in. They are douglas fir. Nothing down there WAS treated, until I found termites, now everything is "boracared" meaning they are soaked in borates.
 

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I think you’re way over thinking this.
Get a couple of floor jacks, bottle jacks or whatever you can get your hands on. Jack up the beam until tight under the joist. If your lifting some of them up an 1/8” no big deal. Go up top and walk on it, if it all feels good put the new post in and be done. If your going to treat the post with anything treat the cut ends before you put them in.
 

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Discussion Starter · #20 ·
OK, so to cover my bases, I went and bought a bottle jack so I'm going to see what happens if I jack the beam up a bit. If I can get a better fit without cracking stuff upstairs, I'll install a taller post. I also bought a piece of steel and some rustoleum paint so I can cut some shims if that doesn't work and also, even if the jacking worked, I'd still have to shim that center joist. If it looks hopeless, I'll take the mark and notch the beam.

Vince
 
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