I have a flooring problem that I need help with. I am remodeling a 100 year-old barn into a small cottage for my wife and I. The floors of this barn are true 2 x 8 and 2 x 10 pine and oak, nailed to true 2 x 8 floor joists of the same materials – these boards are “hard-as-steel.” Over the years the joists have sagged in the center anywhere from 1 – 2 inches off level. I am reluctant to jack up the sagging joists, as they would probably crack, or just raise the whole barn without adjusting the sag. I don’t want to take all the floor boards and joists up and replace them. I would love to just securely screw down the loose floor boards into the joists, and put a new subfloor (3/4″ plywood?) over the existing boards. The problem as I see it is getting the new subfloor level, or almost level. I am assuming that if I put a new wood floor over the new subfloor, it needs to be mostly level.
Is there a way to get a level surface before putting down new sub-flooring? Is there a better subfloor than plywood? What should I consider as a solution, or alternative? My wife and I are newly retired and don’t have a lot of money for an expensive fix. Any ideas or suggested fixes will be greatly appreciated.
Replies
You can shim up the existing. Use a 2X2 (or 2X4 if the sag is over 1-1/2"), lay it full width of the room if possible (use a level line and shim if your room is too wide to do this with one board), scribe the bottom edge to match the floor slope and cut. Glue & screw it down to the existing floor, preferably over the spots where the existing joists are. Glue & screw the new subfloor to these pieces. I generally prefer 3/4" T&G ply for subfloor.
Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.
PS: I once re-did a barn and lived in it for several years. Loved it and would do it again in a heartbeat. Have fun!
Edited 7/18/2009 4:56 pm ET by MikeHennessy
Using the 2x shim approach, how far apart can I place them to adequately support the plywood? Thanks so much for your help!
That depends on what the final flooring will be. Are the existing joists on 16" centers? If so, use that. If not, punt. You should be OK up to about 24" for normal flooring loads, especially if you put down full-thickness hardwood over the new subfloor and lay it perpendicular to the joists. But if you're using tile, I wouldn't go over 16" without someone doing a deflection calc for ya.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
You the man, Mike! Thanks again.
If the existing joists have sagged, why won't they just sag more if you put furring, new subfloor, floor coverings, and furniture on them? I would be looking at jacking them and then supporting them to prevent further sag.
drmusik,
I agree with David. I have jacked lots much older and have never cracked a joist. Run a new sill and jack the sill so everything comes up at the same time. You also seem to have the time to jack in increments.
KK
I'm with the jacking school, and if you want a smooth substrate, glue and nail Advantech.http://www.tvwsolar.com
We'll have a kid
Or maybe we'll rent one
He's got to be straight
We don't want a bent one
He'll drink his baby brew
From a big brass cup
Someday he may be president
If things loosen up
I've been jacking up parts of a house that settled quite a bit, at a rate of about 1/8" per week. Hopefully the slow pace allows time for things to move back into place without too much trauma.
David,I usually don't have that luxury. I have never had a problem as long as I make everything come up at the same time. Set up the laser that gives 3 reference points at a time. Jack a little , move the laser to 3 new points and jack them.KK
Coonass and David are right; jack the joists to within a quarter-inch of flat & level and stabilise them with a new beam set on solid posts and footings. Then you can start thinking about shimming for a new subfloor.
OTOH, many people would probably pay a gazillion dollars for the old-growth wood in your existing floor. Once you've got it flattened out, you could sand and finish it instead of covering it up.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Dinosaur,Take it a step more. Pull up the old floor, rework the joist, add subfloor, reinstall old floor and refinish. We have done similar, came out great.KK
I dunno about removing the floorboards; I'm wondering what size spikes they used to nail that floor down 100 years back. It was a barn, after all. One of the reasons reclaimed antique lumber costs so much is the time it takes to de-nail the stuff before they resaw it. I saw a video of one crew working with what looked like a 7'-long cat's paw....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
The last job I did before retiring was exactly as you described. This was a smaller haybarn with a dirt floor and white oak planks for the loft floor. The flooring planks were rough cut 2x10 on 12" centers. The sag was 2 -3/8" down the middle of an 18'-0" span.The barn was 36'-0" x 50'-0". There was a steel beam thru the middle of the 36-0" span.Each side of the midspan had about the same sag. They must have piled hay to the ceiling ( curved metal roof) to sag that amount with 3x12" joists on 12" centers.
I poured footings for posts and engineered beam for each span. We made two cuts from underneath the floor with a sawzall in each joist. We removed about 1/2" of wood between the cuts,this is so we could raise the joists to level without binding. I had considered using a chainsaw but was wary of the chain binding in the cut. I was never satisified with any brand of sawzall blade to cut wood upside down without tiring before the cut was done. I took a pack of lenox blades to a saw sharpening shop and asked if these blades could be improved on.I was told to come back in the morning and pick up the blades. When I came back they were sharp,these blades were new to begin with but not really sharp. When I asked what I owed, Marty said ."nothin or $30.00, depends on whether their worth it or not". The blades were worth every penny, I used two blades for 200 upside down cuts 12" deep.
Marty got his money and a case of Horlachers beer, that's what he drank and couldn't talk him into a premium beer. Not sure whats lousier ,Horlachers or Iron City.
Each side of the cuts were supported with scaffold and stringers.After the cuts were made we jacked the scaffold heads with the 4x6 stringers up to a straight line. The permanent beam and posts were installed and the scaffold removed.
When we were done the floor was straight and close to level. A few floor planks were renailed to tighten them down.
I had considered other ways to straighten the floor. This seemed to be the surest option,just jacking the center was never considered. 2 -3/8" is too much to try and straighten,I may have lifted the joists before getting them straight if I tried it.
This job turned out very well and under budget, one of a few that turned out under budget.
mike
mike
I agree with Mike 4244 on this one. Cut a notch in the bottom of the joists and jack them up to as close to level as you can. Then you can sister new joists to the old joists or put permenant beams in under the cuts. You may still have to shim and install a plywood subfloor but possibly not, and at least this way you would be assured that your floor would not continue to sag.
I am assuming that this floor is an upper story hay loft, using the space as a living space will not put nearly the live load on the floor that it was once subjected to filled with hay, so the joists may have sagged as much as they ever will, in which case as long as they are structurally sound you could just shim a plywood subfloor to level and install a new wood floor. However, if there is to be any living space below are the ceilings to be drywalled or exposed framing? If they are to be drywalled you will want them to be fairly level as well and jacking the joists up would kill two birds with one stone.
If you do decide to shim the existing floor as is, rather than scribing each 2x4 it is much faster and easier to lay 2x4 sleepers over the entire floor and shim them up to a line (or a lazer) stretched between the high spots. I have done this on a few roofs that had sagged and I needed them flat to install metal. Put screws in through the 2x4s and the shims into the existing floor joists. Then you will still need to install a plywood subfloor over the sleepers. This method is fast, easy and relatively inexpensive. And you do need to have a good flat surface to install hardwood flooring to. I've never tried it with a surface that wasn't flat but I don't think you would have good results with a 2" sag.
Good luck with the project and congratulations on attaining retirement.
Well the first real solution is to embrace the character of an old barn which includes saggy out of level floors..
Since they 've been there for 100 years without failure. To continue to use them as is will simply show character and not look out of place.. I'm sure if you chaeck many of the walls are out of plumb etc..
Embrace that as character rather than a fault.
Cost? nothing..
The next least expensive "repair" is to get underneath the joists and jack them up. Use a 20 ton jack and go slowly and you'll be able to raise the floor nice and flat inside a week of so. Wood is and will remain flexible. Prop them level with pillars. Depending on details you might want one or more pillars per joist. Size is subject to loads. With more details I could advise you. It will never be a billard floor but should be pretty darn nice.
Cost pretty negliable. Say under a hundred dollars if you have a jack and $130. if you don't.
One thing you've got going for you is that 2 inch thick flooring.. Oh, sure the floor will have dips and waves that will make putting down a hardwood floor difficult but you can cure that with a simple sheet of 1/4 inch plywood. (do that part last because you'll tear it up if you put the fimish floor down first.
I worked on a 100 yr old Sears Craftsman catalogue house for some friends that had a 4" sag in the center of the house. Being that it was for a friend I had a long time to fix it. I used lvls new footings and screw jacks. The house needed lots of work, so when I came to work on the weekends I would first screw the jacks up a little bit and go to work. After about 2 months all was level and all I had to do was fix EVERY door on ALL 3 floors that were used to being out of wack. It was well worth the time and effort though and they have peace of mind.
Level is overrated, especially in an old barn conversion. Do you want it to look McMansion new, or are you going for the historic charm effect?
I'm on my 4th (& last!) restoration - I think you want solid & smooth, rather than dead level. It will be easier & less expensive to put down your new sublfoor right over the existing one, perhaps leveling out the most egregious valleys.
Many, many thanks to all who have taken the time to share your expertise and experiences. From each reply I have gained a better perspective, and gotten a better feel for the direction I think I should take. My concerns primarily relate to whether or not to level the floor, and if so, how; If the present floor (boards) can accept new flooring on top of it without leveling; If leveling, then what is the easiest and cheapest way to do so without having to raise the whole structure? The floor is very stable. In its long history it has supported an old IH tractor, and loads of hay. The barn itself is only 16 x 25 feet, with the 16' joists running perpendicular to the 25" length. I have placed two support columns with beam running the length of the barn in its basement for added support. When placing the columns and beam I did raise the joists, I merely stabilized them. There are lots of gaps, and space between many of the boards so refinishing the existing floor might not address those. I also have concern that the nails currently attaching the floor boards would chew-up a sander, even if I could drive them deeper into the boards. I plan to fill between the joists with a closed-cell insulation foam, providing adequate insulation and more rigidity to the floor.If I wind-up leaving the floor "as is," and lay a plywood subfloor, does the subfloor have to be level when using a floating engineered wood or laminate floor? Is there a mortar-type material that is flexible which I could use to level the floor before placing a floating floor? We prefer not to lay carpet, and tile would probably not work as the floor will gave some "give" regardless of what I do. Again, thanks for any input.
If there's already a beam in the basement, then jacking the floor would be a piece of cake. I don't blame it for sagging if a tractor was parked on it.
As many have advocated, I'd give jacking a shot. Heck, what can you lose? If it doesn't work, you haven't lost anything and you can simply move on and install the scribed sleepers.
As for laminate flooring, I find that it's less forgiving than traditional hardwood strip flooring -- and probably not all that much cheaper if you finish it yourself.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.