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Discussion Starter #1
Came across this forum tonight and looks like the perfect place to get some expert opinions. I lay tile for a living and this is the first time I have personally had to add support to a floor. I normally skip this part and tell the customer they should have someone else do it. To keep this job I need to do this myself though.

The floor I am tiling does not meet the calculation you do for a tile floor, but it is only off by 1-2 joists since the room is angled. 2 joists span too far and if I add a small beam between them I am fine. Just to be extra safe I am adding it much longer than needed to support even more of the floor though. Space doesn't really matter since it is a crawl space.

Little info on what's needed. Like I said it is in a crawl space. 4 foot crawl space with cement foundation. Plan on using an 8 ft beam and 2 floor jacks to support it. Was originally just going to throw up two 2x12s screwed together, but they would like to use something smaller if possible. What would you guys recommended for the beam? Are there any laminated options out there that would be the equivalent? I would like to overbuild to be extra safe my tile work stays safe.

Also what do you guys recommend putting under the floor jacks so I don't hurt the cement in the crawl space? It won't have to carry the load of the floor, just be snugged up.

Thanks
Aaron
 

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For one a 8 ft beam with two supports is shoddy. A floor beam should have supports ever 3 to 4 feet really it depends on load but since you gave bare min.. This should suffice. Also do you plan on putting in concrete piers that contact hard pan?
Most of the time you can use the wall footing but the one in the mid span will need solid contact. Also two 2x12 doesn't equal a 4x12 its more like a 4x10. Another thing no floor jacks use 4x4 pressure treated posts with 2x4 gussetts. Also use A23 or better for 4x4 to pier attachment. This is all for permanent attachment. You don't want to come back when a home inspector calls you a hack if they sell.

Oh and one more thing a crawl space does matter. There is supposed to be 18" from beam to floor. I belive this code dates back to at least CABO. You know before the UBC now the IBC. LOL

Just to make this all easier why don't you add some joist to the over span? Now if the joist span from beam to beam/foundo wall is over spanned them adding beam would strengthen that span.

Hope this helps.
 

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Discussion Starter #3
Thanks for the reply..

I will definitely add at least add another floor jack in the middle, they are pretty cheap and this will give me one every 4 ft.


As for putting down concrete piers, that really isn't as option for me. I was hoping putting something directly on top of the cement slab in the crawl space would be enough to spread out the weight. I have seen this done with just multiple sheets of plywood stacked, cut into around 3x3 squares with the jacks over them. Now I have no idea who did this or if it will even work, just seen in done many times over the years. I would think something pressure treated would be down first. What would be my best option?

Lastly, is there something I should use other than two 2x12s?

Thanks
Aaron
 

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You could also build a knee wall 16"oc or whatever your joist spacing is,use pressure treated lumber for this. I used this method to shore up a 2x4 framed roof that was sagging for some 80 years. Just make sure slab is solid at least 4" should be good.
 

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Ok to my best judgment that slab could be a footing with a craw as deap as that its probably hard pan. I would add a 4x8 or 10 and post with 4x4's a 14" 4x4 presssure treated should cost around 15 dollars. a 4x8 beam should cost around 2-3 dollars lineal foot. 8' 2x4 for gussets what 2-3 bucks.

Also another solution to strengthen the floor would be to add joists 8" O.C. Let me tell you these floors are tough. :cheesygri
 

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Discussion Starter #6
Well, If this was my house I would do things different. Frankly though, I don't do this normally as part of my tile installation and don't want to go to the trouble of building a wall in the crawl space. About the most I am willing to do for them is throw up a beam on 3 floor jacks. I have talked to them again and they don't want to have someone else come in and do anything. So basically they want me to throw up the beam with floor jacks somehow or they are forgetting about a tile floor.

So if I am going to just put it on jacks, what would be sufficient to put under them to spread out some of the weight? I will be adding a 3rd jack in the middle.

Thanks
 

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Check with a lumber supplier about LVL (laminated Veneer Lumber). Sounds like you really want to do a first class job, so you might want to think about sistering the other joists with 2"X__". Glue, clamp, nail, move the clamps and nail again. Stagger three rows at 6 to 10 inches, 16p nails are suggested. Any glue approved for subfloor use will be fine. Don't forget to glue the top of the sistered 2X's.
 

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Discussion Starter #8
shopdust said:
Check with a lumber supplier about LVL (laminated Veneer Lumber). Sounds like you really want to do a first class job, so you might want to think about sistering the other joists with 2"X__". Glue, clamp, nail, move the clamps and nail again. Stagger three rows at 6 to 10 inches, 16p nails are suggested. Any glue approved for subfloor use will be fine. Don't forget to glue the top of the sistered 2X's.

Unfortunately sistering isn't an option, or I would just do that since it is really only a few joists that are too long. But it is in a weird angled crawl space with ducting, wires, and pipes in the way. A beam is really the easiest option and will do the job fine, my only real concern was what to put under the 3 floor jacks.
 

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Aaron said:
I was hoping putting something directly on top of the cement slab in the crawl space would be enough to spread out the weight. I have seen this done with just multiple sheets of plywood stacked, cut into around 3x3 squares with the jacks over them...I would think something pressure treated would be down first.
I don't think the idea of transferring loads to non-structural concrete slabs is ever a first class idea - that being said...
I've seen the plywood idea used on numerous occassions in temporary applications. Typically the mat is 30" square (3 pieces per 4x8 sheet) and about 4" thick (the stiffening developed by thickness precludes point loading of the pad). The sheets are always oriented so that the laminate direction changes with each layer. I've seen 90 ton truck cranes succesfully use this method to protect 4" thick asphalt paving. In your case, three 30" square pads will reduce a 5 ton beam load to a ground force of less than 4psi. I would think PT plywood is appropriare throughout the pad.
 

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My idea with adding wall would distribute loads much the same as the plywood idea, since this is supporting midspan your realy designing for live loads,if you were supporting a bearing wall neither of these methods would be appropriate.
 

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Discussion Starter #12
JustaFramer said:
I will not further help you on your hack ways. Git-R-Done

Well.. That was unnecessary. Simply not replying to the thread would be what a normal person who isn't an ass would do.
 

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Aaron said:
Well.. That was unnecessary. Simply not replying to the thread would be what a normal person who isn't an ass would do.
Well what if said I have this tile job and went on to say I am going to use turds for thinset and silly putty for grout. LOL
 

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Lvl

Aaron,

The reply using the LVL is on the right track. These are plywood beams, 1-3/4" thick and we usually double them up (use 2 side by side nailed together.) They are EXTREMELY strong so you could use (2) 7-1/2" LVLs and get the same or more bending stress as the 2x12s with less height. Also, 8 ft is not too long a span. I've used 30 ft LVLs to hold up a roof with no support in the middle (there were (3) 18" LVLs...). However, the more posts you add, the less weight is applied to the concrete at each post so the more the merrier. Remember, the joists will already support a normal floor load so all you are doing is adding supplementary support for the ceramic tile. Not supporting 40 lb/ft live load. I don't think you're a hack...just someone who wants to do it as good as possible on a budget. Good luck.

HLCbuild ;)
 

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Just out of couriosity why would doubling up two 1 3/4" LVL be better than one 4X LVL? Since he think's the cost of a 8x4x12 and 4x4 are costly. LOL Then I am sure LVL's are out of his ballpark.
 

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JustaFramer said:
Just out of couriosity why would doubling up two 1 3/4" LVL be better than one 4X LVL? Since he think's the cost of a 8x4x12 and 4x4 are costly. LOL Then I am sure LVL's are out of his ballpark.
Cost wise and strength wise its the same. It is easier to install the 1 3/4 LVLs one at a time. I'm just looking at the best method to use without breaking up the concrete and installing concrete piers. :)
 

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Discussion Starter #17
JustaFramer said:
Just out of couriosity why would doubling up two 1 3/4" LVL be better than one 4X LVL? Since he think's the cost of a 8x4x12 and 4x4 are costly. LOL Then I am sure LVL's are out of his ballpark.
Care to tell me where exactly I said it was "too costly?"

I said I do not want to get into the trouble of building a wall in a crawl space, that is not my trade and me bringing tools I don't use to the job site and crawling in/out of a 4 ft crawl space is not something I want to do. The most I was willing to do was put up a quick beam on some floor jacks.

My post was specific in asking the best way to do this because I have seen it done plenty of times. If you thought it was a bad idea you could simply say "I don't agree with that method" or something else like a civil person could do. But you seem to insist at acting like a little child at every given opportunity.

People like you are of no help to anyone, you think you are so much better. Its a shame when you get on boards like this and act how you do, gives others in the field a bad name. I am sorry I came in here in hopes of getting advice.

Thank you to anyone who took the time to give a real response.
 

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Quick beam and floor jacks. Your a tard also I don't like you. I think you should stick to tiling and stop asking Carps how to do something then tell them what is what.
Floor jacks are for temperary applications. So next time you post something that your not sure of and don't like the real answer keep it to your self. Over spanning jiosts is a real issue if you don't what to take care of it right don't post your git-r-done crap. I am a professional Carpenter you are not. Tile boy. :Thumbs:
 

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HLCbuild said:
Cost wise and strength wise its the same. It is easier to install the 1 3/4 LVLs one at a time. I'm just looking at the best method to use without breaking up the concrete and installing concrete piers. :)
Why the hell you you need LVL for what a 4x8 could do.
For one this guy doesn't know what he is talking about. A 4 foot crawler with a slab poured. in it ok. One he never mentioned that in the first post. In this case I would of posted off the concrete. Not floor jacks. The 3"-4" concrete slabwould probably sufficed this application with the weight load spread out. Yes a 8" footing would be best. But floor jacks that is were tile boy lost me.
 

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Discussion Starter #20 (Edited)
JustaFramer said:
Quick beam and floor jacks. Your a tard also I don't like you. I think you should stick to tiling and stop asking Carps how to do something then tell them what is what.
Floor jacks are for temperary applications. So next time you post something that your not sure of and don't like the real answer keep it to your self. Over spanning jiosts is a real issue if you don't what to take care of it right don't post your git-r-done crap. I am a professional Carpenter you are not. Tile boy. :Thumbs:
How did I tell anyone "what is what"? I simply said what I was capable of doing and what my options are. I never said anything was right or wrong. Since I am not in 3rd grade I can resist calling you names like "tard"

Man you need to grow up and gain some people skills.

But when calling someone else "tard" and other names try to at least say it correctly. "your a tard" That is you're a tard big guy. Also try spell checking your posts. Find it amusing I am the tard but I can spell works like temporary and all the others you misspelled above.
 
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