I am remuddling an 1880s balloon framed 1.5 story gable-entrance house. It was originally built as a barn/carrige house and was since converted over in 1910. A post earlier today about crossties reminded me of a similar project that I need to tackle.
My roof is about 11:1 with rough cut 2×8’s for rafters spaced 24″ on center. There is no ridge beam. The rafters are nailed together at the peak. The space from the floor of the attic to the peak is about 6′. The ceiling joists for the second story are tied into the rafters with the same spacing. To get to the point, the rear 1/3 of the house along the eave/wall junction is bowing out on both sides and I attribute this to inappropriate structural framing. I would like to pull as much of the bow out of the house before I start siding and so it will last anouther century. If removing the bow is not possible then I am looking for the best way to shore up roof framing without building a new roof altogether. There is no other members present in the roof. Just to be clear and avoid any repetitive comments, I am aware that nothing original to my house is up to code.
This picture does not show the bowing toward the back of the house but it does give you an idea of what I’m working with. Thanks for your suggestions.
Replies
After doing more reading I now realize that the joists for the second floor ceiling/attic floor are actually acting as crossties. Since the house is 1.5 stories and the knee wall is about 5 foot and the second floor ceiling is about 9ft, those crossmembers are like crossties, not joists resting on the top plate. Just thought I would add that to the information.
mainetexan,
Couple of questions.
What is the connection between the "cross ties" or joists and the side wall? Are the walls balloon framed all the way to the rafter connection or do they stop at the attic floor joists and then have knee walls built above that point? I have pulled an old balloon framed building together. In my situation the joists were notched into corresponding notches in a ledger that was attached with spikes to the wall framing. The joists had separated from the ledger which itself had separated from the walls. I used several cable come-alongs and then used anchor plates on the outside of the building attached to a giant turn buckles assembly for the final connections."Poor is not the person who has too little, but the person who craves more."...Seneca
The side walls are balloon framed all the way to the top of the knee wall, which is where the eaves are. The joist/crossties are about 4 to 5 feet above the knee wall where the second floor ceiling/attic floor is. The connection between joist and rafters are huge old nails. I can't really tell if the joist/crossties are notched. The gamble sides of the house have large beams between first/second floor and second/attic floors.
The location of your ties is about halfway up the rafters so technically they are neither collar ties, not rafter ties.The floor joists tied to the balloon frame are performing the function normally assigned to the rafter ties/ceiling joists in other frame styles, while the collar ties are lowered to where they also contribute to preventing wall spread, but not far down enough to take over completely.I am guessing that you have a stairwell going up right about where the worst of your wall spread is, right? The floor joists are interrupted there and so the upper ties are being required to handle more tension than they are able to.Will you be gutting things or trying to deal with this with trim and plaster still in place?
How bad is it?
I've worked on half a dozen homes almost exactly like yours and they seldom fail completely or get a lot worse unless there is rot or if somebody cuts the heart out. The structure is functioning somewhat like a post and beam with the parts functioning as a whole.
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Thanks for the reply. The stairs are in the front right of the house just after you enter the door. The bowing is actually towards the rear of the house on both sides. The house is partially gutted now so no, I'm not concerned with the plaster. Its all cracked to hell anyway. Should I just live with it and move on or is this worth working on?
If you are opening things up, it may be worth the trouble.The floor joists for the second floor should be secured to the wall studs to prevent wall spread there. It sounds like they are not, or that something else is going on.As Dovetail mentions, a series of cable or chain and come-a-longs can pull the walls back together and then re-secure/re-fasten the joists to the studs and make sure that tension is continuous through to the other side. I have done this with a three story house 28 feet wide with good success and I think we even left the cable and come-a-longs in place between the joists
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Piffin,
I've got a few questions about this procedure myself. Dovetail has already helped quite a bit, but I was wondering if you can provide some help as well.
...then re-secure/re-fasten the joists to the studs...
Are a number of 16d framing nails generally adequate to resecure this connection? Are bolts a better idea?
I think we even left the cable and come-a-longs in place between the joists...
Working between the joists is an interesting idea that I hadn't thought of. Are you saying that you left the cables in tension to continue to take up load? How did you secure the cable ends so that they weren't visible from the outside of the house?
One more question: is it generally OK to just crank the walls back together in short order, or is it more prudent to go slowly over a number of days? In my specific case, there are some exterior stucco-type finishes, and I'd hate to pop them off if it can be avoided.
Thanks in advance.
Ragnar
Yes go slowly and perhaps set jacks under the ridge if there is one to push it up as the cables pull walls in.In my case, I have some brackets made up that are an L of steel angle with one leg 4" and the other at 90° about 8". The short leg has holes in it for duplex nails or screws and the longer leg has a 1-1/2" hole burnt into it for snatching a chain to. I hook this over the top plate, tack a couple nails in to keep it from sliding off and hook up.
With the ones I left in place, I had some 1/4" plate made up with 9/16" holes. I tacked them in place on the outside of the top plates and drilled a hole through for an eye bolt. The nut and plate were in the space created by soffit and roof overhang. With a house like the one pictured by the OP, this would be down on the wall, so some more creativity would be needed to keep it hidden dimensionally.So the eye of the eye bolt faces the interior and cables - I think these were 5/16" - and cables strung with turnbuckles. I believe we had the temp brackets in there with the cone-a-longs to pull it together and then set up the permanent cabling to be left with the turnbuckles to get them tight, then pulled the come-a-longs out.I don't recall every detail right now. It was pretty complicated. We also were setting in a flush beam in a ceiling to remove a structural wall so we were parting the continuous floor joists. I think we even had to do this such that we could drill through the LVL beam for the permanent cabling to run straight through. Yeah, There were three cables left in drilled thru that, and two come-a-long setups to pull it all together .This technique is not uncommon. In some old brick churches with lofted ceilings, I have seen threaded rood run all the way across the upper space about every 12' and a 6"x6" steel plate as washer bare on the outside of the brick.
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I missed answering the how to refasten. That always depends on condition of materials. If already split and nail poor, I obviously would not add more nails. Sometimes though, these old places only had one twenty penny nail in a joint like that. The joists we set on a 1x6 ledger let into the studs, and they figured that would handle the load, so they didn't spend too much on expensive steel to pin them.
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Thanks again for the info, Piffin.
mainetexan, I would take the time to open up some "look see" holes through the broken plaster. Whats to lose if you are thinking about moving on anyway?It may not be all that difficult a fix to repair what needs repairing. Could be just joists inadequately fastened to stud, maybe joists that were spliced in there length inadequately pulling apart. The permanent fix if needed can be buried in the floor framing cavity."Poor is not the person who has too little, but the person who craves more."...Seneca
The joists had separated from the ledger which itself had separated from the walls. I used several cable come-alongs and then used anchor plates on the outside of the building attached to a giant turn buckles assembly for the final connections.
Could you please give me some more detail on this? Do you happen to have any pictures?
Unfortunately, I think I may have a similar problem in my own house and might have to address it someday.
I'm wondering what the anchor plates looked like, where they were placed, and how they were connected to the comealongs/turnbuckles.
Did you bring the walls together gradually over a number of days?
What did you use to connect the joists to the studs when you were done pulling things together?
Thanks in advance,
Ragnar
Ragnar,
No photos. I haven't lived in that place for more than 25 years. I didn't mention the wall structure much because there were nothing but vertical 1 x 12 fir boards nailed to the sill beam , the ceiling ledger and again 4' above that to a rafter ledger for walls in this house, tar paper and shingles outside, wall paper inside. I drilled holes thru the walls, and drilled a 5-6 (can't recall exactly how many) 4 x 6 with holes on a matching layout, then propped the 4 x up at the correct height, tacked it on to the side of the building (both sides ) . strung cable thru the holes,and 1/2" x 12' x 6" plates. I had some very large salvaged turnbuckles from a mill building I had helped tear down , connected the cable to the turn buckles and cranked away. There are plates and bolts fabricated for this work I believe. I see them used in seismic retrofits on masonry building but do not know where they are available from. I Used cable clamps to lock the cable in an eye around some bolts and pulled them tight to the beam.
The whole thing was temporary so that I could ensure the building didn't fall apart when I re-secured everything. I had no intention of saving the building for more than a few years ."Poor is not the person who has too little, but the person who craves more."...Seneca
Thanks again for the help, Dovetail.
Piffin and dovetail have given you good advice. Let me add one more consideration. Their advice concerns the fastening of the restraining members to the walls and rafters.
It may be that the rafters and wall studs are not adequately sized to resist the wall spreading. I recently worked on a timberframe house where one of the vertical columns had been relieved to make a flush wall. This column had been acting in the same capacity as your studs in restraining the wall spread though with the forces concentrated at a single point. The column was under a tremendous strain and had bent out some 4 inches. The connection at the floor was still good. In this case we need to pull the top plates together and support the ridge at that point with a column going down to the basement.
Many of these old houses rely on a number of structural pieces which each carry their share of the forces. If everything works perfectly, the structures stand for centuries. If there is a little change, if there is an exceptional snow load or the wood dries out a little too much with age, things start to fall apart. A well engineered modern house or an old house that is a little overbuilt will have no problems. Whatever the problem in your house, it will take a little investigation to determine the cause(s). That is part of the fun.
Good point!Reminds me I once saw one where the 2x4 studs were relieved the full two inches for a 2x8 ledger/rimjoist let in to hang the floor joists from. That only left two inches to resist the outward thrust of the roof.In that case it amazingly had very little deflection. Not sure why, other than overall diaphragm action of the roof and ceiling planes.
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It is amazing how some buildings hold up even with the most egregious stuctural deficiencies. I find it humbling that we don't know how all the parts work together. I know that engineers simply ignore what they can't quantify. Of course this simply makes for a little more safey factor. I can't say that I mind this.
the rear 1/3 of the house along the eave/wall junction is bowing out on both sides
Do you have any idea why the spreading is limited to the back of the house? Are there any dormers that aren't visible in the photo you posted? How does the floor plan of the second floor differ from front to back? Are the effective rafter spans greater in the back?
Lots of questions, I know. But I want to understand this for my own purposes, as well, since I have a similar problem that I can't quite figure out. Hopefully we'll both learn something here.
"How does the floor plan of the second floor differ from front to back?"
Good Question!
That is why is is important to know that he is opening things up.
Maybe the floor joists run the wrong way in that portion of th ehouse
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Thanks to everybody for all the good information and suggestions.
The floor plan consists of three rooms on the second floor. All joists run the short distance of the house (left to right in photo). I am residing the front of my house so I have not really ripped out a bunch on the second floor but I have ripped out the ceiling on the first floor exposing all joist/ledger connections and they don't seem to have pulled away. I have a fealing that there is not enough support between the second floor and roof, including the wierd floor joist for the attic. To me, it seems that if I were to jack up against the attic joist while pulling the sides together when putting new walls upstairs, this may tie things together.
I think you're on the right track. To perhaps restate the obvious, the problem is that the knee walls are being bent outwards by the horizontal load component of the rafters.
Even at 2x8, the rafters are most likely undersized to prevent bending. Thus, the rafters fail to create a "rigid structure" bearing down in a vertical-only load pattern on the top plates of the knee walls.
A number of years ago, we were working on a balloon-framed 1-1/2 story house such as yours and wanted to remove some closet walls parallel to the eaves to increase the footprint of the bedrooms. We got engineering input, and as I recall, the engineers wanted us to sister 2x10s on each side of the existing 2x4 rafters (at 24" centers). Additionally, they called for us to bolt the connection between the paired 2x10 rafters and the ceiling joists.
We all thought it was incredibly overdesigned at the time. Actually, I still do think it was overdesigned, but maybe not quite as much as I initially thought.
So in your situation, I guess you could pull things back into alignment and then do one or more of the following: (1) sister the rafters to increase bending strength; (2) put in one or more beams in the attic to change the load pattern. If you had a bonafide ridge beam, for example, the structural equation becomes entirely different. If there's a beam holding up the ridge, then the tendency for the rafters to thrust the knee walls outward is eliminated; (3) frame in additional walls on the second floor to take up some of the vertical load (which is I think what you were suggeting in your last post).
Let us know what you find out as you do more demolition work and can inspect the framing connections, etc.
Regards,
Ragnar
Edited 6/13/2007 12:57 pm ET by Ragnar17
You can pull the walls back in slowly with the sort of metal rod ties that are frequently used with old masonry buildings. One variety has catheads on the outside of the walls with rods running between. You can gradually tighten the things up. I've seen others with a counter-threaded join in the center - turn it one way, it tightens up, the other way loosens. I saw that at Neuschwanstein, but I'm sure something like it is available here.