Sagging Floor in 100 year old house
Hi,
I am remodeling a 100 year old balloon frame house. The family room is 16’x20′ and had considerable sag (3″) at mid-span. The ceiling joists are true 2×8 and span the 16′ dimension. There is wall upstairs that sits directly above a single joist that also seems to be contributing to the sag.
I have tried several methods to remove the sag, and while it was improved, I cannot seem to get results that are satisfactory (especially for the time I put it).
Here is what I have done:
– Gutted the entire room
– Placed new sistered 2×8 joists
– Sandwiched the beam with wall above with 2 sisters
– Ran a 20′ beam across the entire room and slowly jacked it up just slighly above level
– I nailed and bolted the sisters in place
When I removed the beam, I still had about 1/2 sag below the wall, which tapered out to level at the side walls.
What other options are there to try and remove sag? I’ve thought about using LVL for the sisters. I’ve also talked to an engineer who suggested reinforcing the wall above (with 3/4″ plywood) to make it act like a truss.
I’m not sure that I will redo this room, but I have another room with similar dimensions that has the same problems. I’d like to try and get 1 out of 2 level.
Thanks,
Matt
Replies
Matt
If you ended up with just a 1/2" sag for a 16 ft span you did a GREAT job. Pat yourself on the back and remember you are living in a 100 yr old house. I can show you plenty of new construction that will have more sag in 16' than 1/2".
Thanks for the vote of confidence. I can't say I was really dissapointed with the results...my wife, on the other hand, has started carrying a level with her.My real question was when doing the next room, would using LVL or even custon wood i-joists provide better results? My one concern was that all the additional weight from the sisters, would at some point, actually be contributing to the sag.Matt
Nice job.....take that level away from the wife!
In room #2....is it possible to upset a girder at midspan?
You'll need to post either end, but cutting into the center of your joists and jacking them level to the beam would be beneficial structurally as well as aesthetically.
J. D. Reynolds
Home Improvements
All good suggestions...thanks for the replies. Unfortunately, this room (room #2) includes a staircase. A new post would have to be located adjacent to the stairs...I guess thats more of a design problem.In an effort to save the plaster ceiling, I might try creating a stressed skin panel first. If not, I guess I'll have to look into one of the other options. I'm embarressed to admit that I never thought of sistering 2x10, seems like a simple, elegant solution. Since, the original joists are true 2x8's, I doubt if it would be noticeable even if I pointed it out.
I'm embarressed to admit that I never thought of sistering 2x10, seems like a simple, elegant solution.
Yeah, except 2x10 aren't rated for 16' span.
Regards,
Tim Ruttan
In the second room I'd be tempted to use 2x10s if the ceiling height would allow. Once finished it would take a great eye to spot the difference.
Matt, your real problem is that 16' is too long a span for even a true 2x8. You've done a lot of work, but I don't think sistering them with wood is sufficient to truly solve the problem.
You might want to check out steel joists.
Regards,
Tim Ruttan
next time, why don't you leave the ceiling in place, but strip the plaster off the wall above the sag...then jack the sag out, and glue and screw half inch plywood to the wall, above, on both sides, then take the jack out below. I bet that the stressed skin panel then created would be essantially self supporting, and it would carry the sag in the undersized floor joist as well...
Matt, you will never straighten out joists that have any sag over an inch,especially those that are a hundred years old. Here is what I would do. Remove old joists,several at a time, then replace with new joists or engineered joists. Do not remove all at one time, you need to keep the walls from spreading.I imagine the existing joists are a full 2" thick, probably less than 8" high.Probably rough lumber too. Don't trash the joists, you may be able to salvage material for other projects.
The last job I did on an old (156 years old now)I salvaged the joists and some other framing materials.These were all from heart pine.Everything from cabinets to a nutcracker turned on a lathe came from this lumber.
The first time I tried to salvage old sagging joists, I had about 2 3/4" sag in the middle of a 15'-0 span. The joists were 3x5".I tried raising the joists with a jack.Waste of time, I could easily raise the joists, but they were not close to straight along there length.It took me less than a day to replace the joists with engineered joists, about 17 joists.
mike
Mike,Thanks for the info. By engineered joists, do you mean LVL or wood I-joists?Thanks,
Matt
I joists, I used TJI brand, they are reasonably priced. Your lumberyard will help you with the correct sizing of the joists. You need to tell them the total span and the centers, subfloor material .
mike