Support Beam for spongy floor.
#1
10-28-18, 06:17 PM
Support Beam for spongy floor.
Hello,
I’m trying to put a beam in to brace the floor in my Family Room. The room is 15 feet wide and I feel a little sponginess. My plan is to build my own beam (24 ft long) using maybe 2- 2x10’s sandwiching plywood in between. I’ll use jack posts for the support.
The floor joists are exact measurement- 2”x9”.
Questions:
Would it suffice to use 3 jack posts? One on each end and one in the middle?
Would the Jack posts being 12 feet apart be enough to take the sponginess out of the floor?
Also, what type of wood (Doug Fur)?
Thanks for any input...
I’m trying to put a beam in to brace the floor in my Family Room. The room is 15 feet wide and I feel a little sponginess. My plan is to build my own beam (24 ft long) using maybe 2- 2x10’s sandwiching plywood in between. I’ll use jack posts for the support.
The floor joists are exact measurement- 2”x9”.
Questions:
Would it suffice to use 3 jack posts? One on each end and one in the middle?
Would the Jack posts being 12 feet apart be enough to take the sponginess out of the floor?
Also, what type of wood (Doug Fur)?
Thanks for any input...
Last edited by joeponcho; 10-28-18 at 06:32 PM. Reason: Add info
#2
10-28-18, 10:27 PM
Group Moderator
Better to build small walls, which are permanent, under the ends of your beam than jackposts, which are meant to be temporary.
#3
10-29-18, 04:13 AM
There was a 12'x14' addition built onto my living rm before I bought the place. For whatever reason they ran the joists the long direction which resulted in a slight give when walking across the floor. I used two 2x6 [beam] supported every 6' in the crawlspace. That was about 25 yrs ago and the floor has been solid ever since.
I assume you have a basement under the family rm. How is that space used? I like SS's suggestion for walls to support the beam.
I assume you have a basement under the family rm. How is that space used? I like SS's suggestion for walls to support the beam.
#4
10-29-18, 05:38 AM
So, this is similar to what I have done to several of our homes where there was same soft flooring.
Typ I would buy a small glue lam but making one is acceptable. In all cases I also used adjustable posts and results were great, rock solid floors. I also screwed the beam to each joist which helps also!
Remember, these are not load bearing all they are doing is stiffening up the floors to eliminate the deflection that occurs when someone walks on the floor, minimal load!
With my glue lam I have some areas that were probably 15' span, with the 2x10 construction the 12 should be fine!
Typ I would buy a small glue lam but making one is acceptable. In all cases I also used adjustable posts and results were great, rock solid floors. I also screwed the beam to each joist which helps also!
Remember, these are not load bearing all they are doing is stiffening up the floors to eliminate the deflection that occurs when someone walks on the floor, minimal load!
With my glue lam I have some areas that were probably 15' span, with the 2x10 construction the 12 should be fine!
#5
11-02-18, 12:33 PM
Thanks for the info. After researching for the past week, I think I'm going to use either
3- 2x10's or 3- 2x8's and support them with Jack posts every 8 feet. Since this is not weight bearing, would 3- 2x8's suffice supported every 8 feet?
For some reason the previous owner put in 1 jack post with 3- 2x8's sandwiched together but they're only 4 feet long.
Is there a big difference between 3- 2x8's & 3- 2x10's?
3- 2x10's or 3- 2x8's and support them with Jack posts every 8 feet. Since this is not weight bearing, would 3- 2x8's suffice supported every 8 feet?
For some reason the previous owner put in 1 jack post with 3- 2x8's sandwiched together but they're only 4 feet long.
Is there a big difference between 3- 2x8's & 3- 2x10's?
#6
11-02-18, 12:39 PM
The 2x10 will always be stiffer but remember the load that these are supporting is nothing more than the weight of someone walking on the floor so a couple of 2x6 would be sufficient,
#9
11-02-18, 05:47 PM
Group Moderator
Remember, these are not load bearing
#10
11-02-18, 07:35 PM
Thanks stickshift. I’m confused though. You’re not the only person to say that these Jack Posts are temporary, yet I see them in just about every basement I’ve been in that was built after the 1960’s. What do you consider a “Permanent Post?”
#11
11-02-18, 07:57 PM
Also, I’m researching “Permanent Jack Posts” and what does this statement mean: “Can be used permanently if as a secondary support.” It’s a contradiction in terms, isn’t it?
#12
11-03-18, 04:52 AM
You’re not the only person to say that these Jack Posts are temporary, yet I see them in just about every basement I’ve been in that was built after the 1960’s.
#13
11-03-18, 06:27 AM
Well there really is no other way to fix what you are trying to do other than adding additional support, every house I have done this to, at least 3 that I can recall then had the basement finished afterwards. so the beams and posts were then inside walls so they were not visible.
Would it raise questions, maybe but then you have to live with the soft floors or take them down before selling,
I also always used the solid posts, not the really cheap adjustable ones although for the loads you are applying, the weight of a person and the beam itself, it would be more than sufficient!
https://www.doityourself.com/forum/a...1&d=1541248005
Would it raise questions, maybe but then you have to live with the soft floors or take them down before selling,
I also always used the solid posts, not the really cheap adjustable ones although for the loads you are applying, the weight of a person and the beam itself, it would be more than sufficient!
https://www.doityourself.com/forum/a...1&d=1541248005
