Replacing sagging beam with LVL

Reply

  #1  
Old 02-18-06, 12:29 PM
N
Member
Thread Starter
Join Date: Feb 2006
Location: MI
Posts: 156
Received 0 Votes on 0 Posts
Replacing sagging beam with LVL

Hi,

I just bought an old house that has quite the sagging main beam located on the ceiling of the first floor (also the floor of the second floor).

The previous owner tried to fix it, but still undersized the beam for the span, and I have about a two inch sag according to my chalk line. I have the correct beam size located, and will be using an LVL. But, I wanted to see if anyone had any sugegstions for how to be out with the old and in with the new.

THe beam spans 16 feet accross the room. The roof trusses and the floor joists above the beam run perpendicular to the beam obvisouly and are 8 feet long (from the point the rest on the beam to the point the rest on the exterior walls. The floor joists are on 24 inch centers also (unfortunately).

I plan on using some stanchons or floor jacks to jack up the sagging beam to level. Then, I am envisioning making two 16 foot stud walls, and supporting the upper floor on each side of the existing beam, near the point where the 8 foot floor joists end. This will effectively give me two structures to support the upper floor. Then, I plan to take the existing sagging beam out, replace it with the appropriate sized beam, then remove the temporary stud walls.

Does this sound like a decent plan? Can the temporary stud walls just be 2x4 on 16" centers? Or do I need to double up anywhere since they will bear the load. Or, would I be better off using mulitple stanchons.

Also, I need to effectively raise the floor above 2" or so, from where it currently sags. Do I risk anything except maybe cracking some drywall?
 
  #2  
Old 02-19-06, 09:06 AM
Join Date: Dec 1999
Location: South Dakota
Posts: 3,140
Received 0 Votes on 0 Posts
Noake

I would build my support walls out of 2 x 6's. Just a little more strength. 16" OC and double stud the old beam. It is going to be very hard to jack up the old beam 2". You cannot no it at one time. Maybe 1/2" at a time over a period of a week. When you jack anything up there will be problems. Remember, your roof is up there also. This is not an easy job. Good luck and me careful.
 
  #3  
Old 02-19-06, 10:45 AM
C
Member
Join Date: Feb 2005
Posts: 67
Received 0 Votes on 0 Posts
I would reccomend using shoring posts instead of stud walls. the posts have threaded adjustment collars that will allow you to slowly jack the floor up over a period of time. you would need a support beam on both sides of the sagging beam to be replaced and with four posts per side spaced at 6' o.c., you will have eight posts total. you would need to use a continuous 4x4 on the first floor (for the post to sit on and distribute the load) as well as the underside of the second floor (as a spreader beam to suppor the second floor joists).

You can rent posts like this from any tool rental place. i would take as much time as possible jacking up the floor, as cracks in drywall and such can be caused. depending on the basement condition, you may need some temporary shoring below the first floor as well.

here is a website that shows a typical shoring post. you set the rough height with the pins and then adjust with the threaded collar:

http://www.sciglobal.com/falsework/20kPostShore.html
 
  #4  
Old 02-19-06, 11:05 AM
W
Join Date: Dec 2005
Location: USA
Posts: 3,185
Received 1 Vote on 1 Post
Noake - I wouldn't feel comfortable replacing a main carrying beam with 24" OC 2 X 4 stud wall. Even temporarily. IMO buy a sufficient number of house jacks (around $20-$25 at the local BOB-probably cheaper than renting over the amount of time you'll need them) and jack the existing beam in small increments. For the first couple of days I wouldn't go over a 1/4" a day. Be watchful of things happening not only structurally but also with plumbing and electrical. You also need to watch whats happening in the attic. Is the ridge beam also sagging?
Once you get the beam straight then you can add temporary support. I would go with a built up beam of 3 wide sistered 2X6" supported by lally posts instead of a stud wall.
A couple of questions - What is the condition of the existing beam? Is it cracked or just bent? Can it be left in place and the new LVL support installed alongside?
 
  #5  
Old 02-19-06, 12:17 PM
Join Date: Dec 1999
Location: South Dakota
Posts: 3,140
Received 0 Votes on 0 Posts
Noake

Just going to jump in one more time. I noticed two answers, both of which did not like your stud walls. I agreed with your stud walls because this will spread the weight distribution out along your floor instead of in certain spots.
Also my answer comes from many years of experience in replacing beams.
Good Luck. Time to watch the NASCAR RACE.
 
  #6  
Old 02-20-06, 03:19 PM
Join Date: Dec 1999
Location: South Dakota
Posts: 3,140
Received 0 Votes on 0 Posts
Noake

I woke up this morning at 2:30 am thinking about your job. I realized that there was something I forgot to mention to you. Here it is. When jacking up your beam, you must be very consious of what is happening. Be sure that when you think you are jacking the beam up, that you are not really jacking your floor down instead. You may have to beef up under your floor where you put your jacks to prevent this from happening. Been there, done that. Just a middle of the night thought. Good Luck
 
  #7  
Old 02-20-06, 07:05 PM
N
Member
Thread Starter
Join Date: Feb 2006
Location: MI
Posts: 156
Received 0 Votes on 0 Posts
Thanks for all of the replies and help. Thanks Jack, I have thought about the jacking the floor down business too. So, I think I have a handle on it. My next question is this- I went to the Home Depot to try to order an LVL, and it says that I need a 14inch by 16 foot LVL, that is 4 plys (4 LVLs glued together) in order to span the 16 foot length of the beam. I cannopt afford to give up this headroom, so I am looking to a steel beam instead (unless anyone has any different thoughts)/ So, my next question is, do I need some sttel posts on either end of a steel beam, as well as directly below in the basement? The existing beam is set on top of doubled up 2x4s in the walls, but I am wondering if these will support steel. Any ideas? I will start the gradual 1/4 at a time process of rasing the existing beam.

Thanks for the help Jack and others, but please don' twake up in the middle of the night over it- you guys are great.
 
  #8  
Old 10-20-09, 10:17 AM
B
Member
Join Date: Oct 2009
Location: New York
Posts: 1
Received 0 Votes on 0 Posts
Hi, I came across your posting as I too have the same problem of a sagging beam. My beam spans 14ft and sags approximately 1" at it lowest point. Pretty much I have the same scenario of an opened up room on the first floor, above the opening on the second floor rest floor joists running perpendicular to the beam. The current beam is insuffucient in size and material for the span and needs to be replaced. Would you be able to provide info on what you ended up doing?
 
  #9  
Old 10-20-09, 11:04 AM
C
Member
Join Date: Oct 2009
Location: Pennsylvania
Posts: 104
Received 0 Votes on 0 Posts
The way to solve your problem is to expose the beam and look at what is causing it to sag.

Tear the whole house apart if necessary and remove all structure that is not carrying load.

Sometimes it is just due to a lack of proper engineering that causes a sag in the house but more times then not, it is due to problems with the foundation or the house settling.

I would put cribbing under the house to carry the load where you put the post jacks and I would be very careful how much I jack up at one time.

Micorlam beams are great because they are engineered to be much stronger then any other type of wood. But you need to remember that if the walls cannot support the weight, just adding a beam under the floor is not going to solve the problem.

You need to open it all up and examine the structure to find out what the problem might be and do a remodel job to all the rooms where the beam is going to affect the elevation change to the floors and walls.

Look for problems with the plumbing and wiring while you are in there and for any problems with a leaky roof.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: