# Bouncy floor



## chrisasst (Feb 12, 2013)

I have 2 rooms that I am gutting...etc.. The one room is right above the other. And the bottom room is right above my basement. The upper floor is very bouncy.  What can I do to support this. I am thinking I need a beam of sorts right?  Kind of like a load bearing beam or something right...

Or any other suggestions?


----------



## lukem (Feb 12, 2013)

chrisasst said:


> I have 2 rooms that I am gutting...etc.. The one room is right above the other. And the bottom room is right above my basement. The upper floor is very bouncy.  What can I do to support this. I am thinking I need a beam of sorts right?  Kind of like a load bearing beam or something right...
> 
> Or any other suggestions?



Add joists.


----------



## Morgan (Feb 12, 2013)

Pictures would help getting some ideas coming your way.  Sight unseen here is what I can offer, you could double up the floor joists (if they are not full of wires and pipes and what not.  You could add in some sort of beam but the load of this beam would have to carry straight through to your basement.  Sometimes just adding blocking between the joists can take some spring out of a floor.  Post some pics, let us see =)


----------



## Jack Straw (Feb 12, 2013)

Diet?


----------



## chrisasst (Feb 12, 2013)

Morgan said:


> Pictures would help getting some ideas coming your way. Sight unseen here is what I can offer, you could double up the floor joists (if they are not full of wires and pipes and what not. You could add in some sort of beam but the load of this beam would have to carry straight through to your basement. Sometimes just adding blocking between the joists can take some spring out of a floor. Post some pics, let us see =)


 
I will get some pics tomorrow. I tried blocking between the joists and didn't help.


----------



## Ehouse (Feb 12, 2013)

Two tricks I can think of; 

Glue and nail a bottom flange to each floor joist turning them into I-beams. 

Stretch a taught 1/4" cable across the bottom of the joists in the middle and perpendicular.

Ehouse


----------



## brian89gp (Feb 12, 2013)

What size joist and how long of a span?

-Doubling a joist up (going from one 2x8 to two 2x8's sistered together) is roughly the same stiffness going 2" more in depth (going from 2x8 to 2x10)
-A LVL or PSL of the same dimensions is stiffer then sawn lumber.
-Full height solid blocking at 1/3 spans will stiffen up the floor slightly as it transfers the point load of your feet to other joists

If you do a beam you are probably going to have a pretty decent sized beam and you need to support the point loads all the way down to the basement


----------



## Frozen Canuck (Feb 13, 2013)

Bridging will perform better than blocking & when you do the gut if you dont see any bridging thats a large part of the reason why you feel a bounce. Unless of course the joist are undersized for the span.


----------



## Ehouse (Feb 13, 2013)

One more;

Glue-nail 1" or 3/4" plywood on the face of the middle third of each joist (partial sister). If the bellies are stiffened the ends will not deflect much if at all.  It's important to have close nail spacing.

If you take this ,or a similar approach, start with the middle joist or two, then test the floor. It's deflecting in all directions not just along the lengths of the joists (as a diaphragm). 3 or 4 joists in the middle might be enough.


----------



## jharkin (Feb 13, 2013)

Ehouse said:


> Glue and nail a bottom flange to each floor joist turning them into I-beams.


 
Wont make a significant difference. Its the vertical face of the I-beam that imparts stiffness up and down.


----------



## jharkin (Feb 13, 2013)

Chrisasst,

I think that to really give sound advice we need to first understand _why_ the floors are bouncy. There could be many reasons - some quite simple and easy to rectify, others not so much.

It could be any one of:


The finish and/or subfloor may just have pulled away from the joists (not uncommon if its a 100+ year old place with face nailed wood flooring)
This can be rectified by re-nailing, or better screwing down the floors. Tom Silva on TOH once showed a neat screwing system where the screw heads broke to be invisible

The joists may have been weakened by years of plumbers and electricians notching them out to run pipes, ducts and wires
Obvious fix here is to sister the offending joists

the joists may have been undersized to begin with.
A builders span table will tell you if this is the case, and if so, fix is to add more joists or a support beam and/or posts (if going the beam/post route you might want to consult a structure engineer)

A load bearing wall might have been removed at some point
Here again we are looking at adding support beams, etc.... engineer time

 
Pictures,  any detail on the above ideas, and some more info on the age and construction  of the house will help. (all of the above assumes the place is less than 100 years old and a typical platform frame house. If its stone, or is older and of either balloon or post/beam framing there are even more possibilities to consider)


----------



## ironpony (Feb 13, 2013)

jharkin said:


> Wont make a significant difference. Its the vertical face of the I-beam that imparts stiffness up and down.


 

exactly, 1/2 plywood or OSB will add more rigidity then a sister joist,. there are so many variables this is hard to remedy without pictures and more info
age of house would help greatly


----------



## jharkin (Feb 13, 2013)

ironpony said:


> exactly, 1/2 plywood or OSB will add more rigidity then a sister joist,. there are so many variables this is hard to remedy without pictures and more info
> age of house would help greatly


 
Agreed.  I just thought of another possibility, could even be failed joist hangers.  I'm sure there are others I'm not thinking of also.


----------



## ironpony (Feb 13, 2013)

jharkin said:


> Agreed. I just thought of another possibility, could even be failed joist hangers. I'm sure there are others I'm not thinking of also.


 

or like the house I was in yesterday with the joists hangars installed with 8D nails in less than half the required pattern


----------



## Beer Belly (Feb 13, 2013)

I have the same problem with bouncy floors, and I'm gonna glue and screw 1/2 Plywood on every Joist.....one of these days


----------



## Ehouse (Feb 13, 2013)

ironpony said:


> exactly, 1/2 plywood or OSB will add more rigidity then a sister joist,. there are so many variables this is hard to remedy without pictures and more info
> age of house would help greatly


 
Don't wish to argue with you gents, but a TJI with a mere 1/2" ply or OSB web will span considerably more than a 2x joist of the same depth, and be stiffer to boot.


----------



## chrisasst (Feb 13, 2013)

The house is a 1900 house.  When I moved in there was carpet in the upper room.  Which I ripped out. All that was/is under that is T&G boards.  All of them appear to be still attached to the joist.  

The first pic is when you walk into the room.
Second pic is the area ( middle) where it is bouncy
Third pic is showing they fastened the joist ( if you can see it)
Fourth pic is a corner / window I have no idea what to do with.

As you can see someone put up newer joists next to the old ones.


----------



## ironpony (Feb 13, 2013)

Ehouse said:


> Don't wish to argue with you gents, but a TJI with a mere 1/2" ply or OSB web will span considerably more than a 2x joist of the same depth, and be stiffer to boot.


 
please reread what I wrote, that is exactly what I said, plywood and OSB will add MORE rigidity than a sister joist


----------



## jharkin (Feb 13, 2013)

OK, yeah we can see its been sistered already, but no obvious big notches in the joists. So, Im guessing the problem is the joists are undersized for the span spacing or some supporting wall was removed. 

The one thing I can quite tell from that third image is how the joists are attached.  In balloon framing the studs run from the mudsill all the way to the top plate in the attic, and the second floor joists would be nailed to the sides of the studs, and should also be supported on a ledger band that is notched into the studs.  Platform framing is modern construction where the second floor joists sit on top of the plate for the first floor.

Either way I have  to punt at this point at being beyond my depth to advise on the best course of action.


----------



## ironpony (Feb 13, 2013)

jharkin said:


> OK, yeah we can see its been sistered already, but no obvious big notches in the joists. So, Im guessing the problem is the joists are undersized for the span spacing or some supporting wall was removed.
> 
> The one thing I can quite tell from that third image is how the joists are attached. In balloon framing the studs run from the mudsill all the way to the top plate in the attic, and the second floor joists would be nailed to the sides of the studs, and should also be supported on a ledger band that is notched into the studs. Platform framing is modern construction where the second floor joists sit on top of the plate for the first floor.
> 
> Either way I have to punt at this point at being beyond my depth to advise on the best course of action.


 

agree with above, there are many issues here that need to be looked at first hand, span, joist size, spacing, connection etc.


----------



## semipro (Feb 13, 2013)

It may have been covered already or you may have dismissed early on as an option;
adding a post with a beam perpendicular to the existing joists seems the simplest solution to me.  The post would need to be supported all the way to the basement floor somehow (not just to the first floor).


----------



## brian89gp (Feb 13, 2013)

2x8 joists with 24" spacing on what looks like a 12-14' span?  That would definately flex a bit.

Couple things I see:
1. Only partial height blocking, not that full height blocking helps all that much but partial height blocking doesn't really do anything at all.
2. Looks like someone used two new pieces of lumber to sister each joist as I see joints in the middle.  It should be one piece end to end otherwise it doesn't do much (or use a very liberal amount of glue and fasteners, probably cheaper to just buy a longer joist)

Either properly sister the joists, go one or two sizes up in the joists, or put a beam in.  FYI, a beam to hold a floor mid-span over a 12-14' unsupported length is pretty large.


----------



## Ehouse (Feb 13, 2013)

ironpony said:


> please reread what I wrote, that is exactly what I said, plywood and OSB will add MORE rigidity than a sister joist


 

Thanx for the heads up to reread your post, the first word of which was "exactly"  with a reference above to jharkin's which stated "Its the vertical face of the I beam that imparts stiffness up and down."

Please reread what I wrote;  I was not talking about sistering at that point.  At any rate , it's about a bouncy floor, and now that I've seen the pics., I think first responder lukem had it right.  Add joists to make 12" spacing


----------



## lukem (Feb 13, 2013)

At that span I'd add the joists to make it 12 OC.  Sistering won't help a ton as you seen because a lot of the bounce may be coming from the deflection of the subfloor...not the structure.  When understructured add wood where there isnt...not more where there is.  Might even consider going next size up on new joists and fur out the difference on existing.

Adding a beam would,as others have said, would increase point loads where the structure underneath may not be able to support it.  I don't think you want to go there.


----------



## chrisasst (Feb 13, 2013)

ok very novice here..... What do I fasten the joist to?  Do I have to add more wall studs some how?


----------



## lukem (Feb 13, 2013)

Need better pics of wall and how current joists are joined to answer that one.  Get that insulation out of the way so we can see exactly what is going on there.


----------



## seige101 (Feb 13, 2013)

What is holding up the floor joists in the areas colored in red?


----------



## chrisasst (Feb 13, 2013)

seige101 said:


> What is holding up the floor joists in the areas colored in red?


 
the 2 on the left, there is nothing.  The studs or whatever was there were all rotted. The one on the right is nailed into the stud...


----------



## seige101 (Feb 13, 2013)

That would definitely contribute to a bouncy floor! Nothing to hold the joist in place! Looks like the need for a proper header over that window also.


----------



## chrisasst (Feb 13, 2013)

seige101 said:


> That would definitely contribute to a bouncy floor! Nothing to hold the joist in place! Looks like the need for a proper header over that window also.


 
Funny thing is, it is not bouncy in that corner.  Only in the middle.  
Yeah that whole corner / window needs to be replaced.  I just have to figure out how to put a studs there because the floor in that corner is also gone due to it rotted.  That whole corner is more of a night mare than the bounce is, but...


----------



## Bret Chase (Feb 13, 2013)

To the OP... you've got a "Balloon framed" house...  the span looks to be about 18'?  the only way you're going to take the bounce out is to put in a mid span beam... and actually frame under the unsupported beams.


----------



## Ehouse (Feb 13, 2013)

I own a house built in 1817 and one built in 1890+-.  Both were built with neither balloon or platform frame, but with what I'll call a hybrid post and beam where the top plate (rim joist) on a given wall is a 6"x 10" or such.  This eliminated the need for collar ties or strong joist tie ins because the top plate acted as a beam both vertically and horizontally.  The floor joists are more like small beams on wide centers (2' or more) and are notched into the rim joist beam on top (top chord bearing) and perhaps toe nailed into its face with no ledger.  From your pics. it looks to me like that's what you have, so you can use joist hangers face nailed (use hanger nails, which are thicker) with new joists of the same depth ( 2' centers are not good for ceiling sheet rock).  Also, inspect the ends of the joists where they join the rim beam, they will often be split lengthwise.  if so, jack up each joist in the center and the split should close up. you can then snug it up with a hanger or plumber's strap.  Adding a 6" lag about 4" back from the join will help.


----------



## Ehouse (Feb 13, 2013)

Bret Chase said:


> To the OP... you've got a "Balloon framed" house... the span looks to be about 18'? the only way you're going to take the bounce out is to put in a mid span beam... and actually frame under the unsupported beams.


 

Could be balloon frame, pic. #3 shows studs under both joist and sister so hard to tell.


----------



## chrisasst (Feb 13, 2013)

Bret Chase said:


> To the OP... you've got a "Balloon framed" house... the span looks to be about 18'? the only way you're going to take the bounce out is to put in a mid span beam... and actually frame under the unsupported beams.


 



So something like this.. I could put a leg in the middle.  Not Ideal but....
Also I think that window on the right is dead center of the room.,


----------



## Bret Chase (Feb 13, 2013)

Ehouse said:


> I own a house built in 1817 and one built in 1890+-. Both were built with neither balloon or platform frame, but with what I'll call a hybrid post and beam where the top plate (rim joist) on a given wall is a 6"x 10" or such. This eliminated the need for collar ties or strong joist tie ins because the top plate acted as a beam both vertically and horizontally. The floor joists are more like small beams on wide centers (2' or more) and are notched into the rim joist beam on top (top chord bearing) and perhaps toe nailed into its face with no ledger. From your pics. it looks to me like that's what you have, so you can use joist hangers face nailed (use hanger nails, which are thicker) with new joists of the same depth ( 2' centers are not good for ceiling sheet rock). Also, inspect the ends of the joists where they join the rim beam, they will often be split lengthwise. if so, jack up each joist in the center and the split should close up. you can then snug it up with a hanger or plumber's strap. Adding a 6" lag about 4" back from the join will help.


 
It sounds like your houses are what we call "3/4 framed" in my area... basically post & beam in the walls with a conventional roof.... it's also how my house is framed... there are exactly 12 posts that hold up my entire roof... the studs are mortised into both header and sill... with no nails.

2' centers is fine for 5/8 sheetrock... but you *really* should strap the ceiling out if you're going to sheetrock it..


----------



## Bret Chase (Feb 13, 2013)

Ehouse said:


> Could be balloon frame, pic. #3 shows studs under both joist and sister so hard to tell.


 
perhaps you could call it.. "ballon framed, improved"?  I have learned over my career... when you start gutting old houses... you NEVER know what you're going to find...


----------



## Bret Chase (Feb 13, 2013)

chrisasst said:


> View attachment 93642
> 
> 
> So something like this.. I could put a leg in the middle. Not Ideal but....
> Also I think that window on the right is dead center of the room.,


 
if you used a relatively small LVL or PSL engineered beam... my gut says a 5x7.. it would massively improve the upper floor... and depending on if 1/360 deflection is important... you most likely won't need the center post.


----------



## Ehouse (Feb 14, 2013)

I think it's either beam or extra joists.  If its balloon frame, beam would be easier, but you'll need a header over the window, strapping or other modification for the ceiling, and live with the visual reality of a single beam in the middle of the room.  If there's a substantial rim joist/beam at the joist ends, hanging new joists will address all of the above concerns.  Check the ends of the existing joists for splits which could be causing the bounce.  The ceiling was built to hold up lath and plaster, so something has deteriorated structurally.   You could do the beam in either case.


----------



## TresK3 (Feb 14, 2013)

I'm concerned about your comment that the floor in that corner is rotted.  Do you mean the subfloor (or whatever is over the floor joists), or are the joists and other structural members bad, too?  If so, you may want to address this first, before you start building/reinforcing on top of that area. 

Beyond that, I'm liking the idea of extra joists in-between the existing ones; maybe even go up a couple inches in size.  Make sure everything is well supported on the ends.  Also, if you add a plywood floor on top of the T&G that's up there already, and really screw it down into the joists AND between the joists (into the T&G), that will help to tie everything together.


----------



## backpack09 (Feb 14, 2013)

It sure looks like your flooring is not touching your original joists in a lot of places.  

Blocking between joists, installing 2x8s to sister over gaps in new joists, add 2 rows of 3" long screws every 10-12 inches to connect the existing joists together, and install an additional 3/4-1" subfloor with the weak axis perpendicular to the joists is what I would do.  Beams are ugly.


----------



## semipro (Feb 14, 2013)

OP, I guess another thing to consider:
adding or sistering to joists, adding subfloor, installing a beam without a central post, all are options that will add additional loads to what may be already overstressed or inadequate wall and foundation structures.


----------



## chrisasst (Feb 14, 2013)

TresK3 said:


> I'm concerned about your comment that the floor in that corner is rotted. Do you mean the subfloor (or whatever is over the floor joists), or are the joists and other structural members bad, too? If so, you may want to address this first, before you start building/reinforcing on top of that area.
> 
> Beyond that, I'm liking the idea of extra joists in-between the existing ones; maybe even go up a couple inches in size. Make sure everything is well supported on the ends. Also, if you add a plywood floor on top of the T&G that's up there already, and really screw it down into the joists AND between the joists (into the T&G), that will help to tie everything together.


 
Well the tree trucks that the floor is on ( or whatever they are) look ok. Also in that corner and that side of the wall, underneath those is the stone foundation that some of it sits on. I will try and get a picture next time I can in the day.  So if I can figure out how to put wall studs there in that corner, rough a new window out,  I think it will be ok there.

This room is just a mess.


----------



## Eatonpcat (Feb 15, 2013)

Good Luck, I would listen to Iron Pony...His advice is always good when it comes to structure!


----------



## jharkin (Feb 15, 2013)

To the OP-
It sounds like you have extensive structural issues to address, especially in that exterior wall. A book I highly recommend is Renovating Old Houses by George Nash. It documents a lot of structural techniques that might apply. Caveat in this situation if it were me I would take the book just as a starting point to get ideas and probably want to bring in a pro.



Some more about framing methods. This is what a true balloon frame looks like for anyone interested:







First known balloon frame building was around  edit 1832 1840ish. Before that everything is post and beam, though there are lots of variations in how post and beam is done. Some had no studs at all and plastered the sheathing directly, others had studs at odd intervals to support the interior wall finish. And then there are variations like plank framing that had had continuous 1-2" vertical boards mortised into the sills and plates (eliminating the bracing). Plank houses are especially tough to update as the plaster is typically applied right to the inside of the planks leaving no cavities to run wires or insulate.

After the civil war balloon framing started to spread, first popular out west, but it didn't reach New England until the late 1800s You can find post and beam houses in NE up to the 1860s and later, and even after that they would build a hybrid called a "New England braced frame" , that was a balloon frame with post and beam type Corner posts added and some knee bracing. After 1900 I think its mostly pure balloon framing and then platform framing sometime before WW2.

Ehouse, of course am no expert, but your 1817 house sounds like standard post and beam construction (both my mud sills and top plates are 6x7 beams) and the 1890 house is probably the New England hybrid frame type I described above.

Anyone who has real interest in this stuff, there is a great book called A Building History of Norther New England that shows the evolution and has drawings of each type. Its a great resource written by the first curator of the Strawberry Banke Museum..


----------



## jharkin (Feb 15, 2013)

Ehouse, does this look familiar to your 1890 house?


----------



## Ehouse (Feb 15, 2013)

You're probably right on the older one, post and beam with stud infill. Late 1890's house a little different in having the full size beam for the very top plate but otherwise, that's pretty close. A surprising feature to me of both houses is the lack of collar ties, king post, queen post or ridge beam, with fairly slim rafters from plate to peak and notched together. With rough sawn skip sheathing, I wonder how they've withstood shear forces for all these years. If the carriage barn is any indication, the house is probably framed mostly with Chestnut and Yellow Birch (bark still on).

Many of the older Victorian style homes in this area are apparently kit houses from Sears and Roebuck right down to the interior trim mouldings. I wonder what framing they used?


----------



## G-rott (Feb 25, 2013)

Engineered lumber is great for beams if you have the head room, two beams at 1/3 span would allow a shallower beam and possibly easier framing. If headroom is a factor you could cut you beam by supporting both sides and cutting out space for the new beam and hangers.

Don't rule out steel if headroom is a major factor.


----------

