Sweetwood 11.1 Theater destroy and rebuild - Page 4

As long as the rigid metal components are shielded by decoupled mass of ceiling, you won't need to. The actual supply and return for the theater would be flex, etc following best practices of soffit construction.

The soffit acting as a muffler.

Short story. Pressure valve burst on the hot water heater. Stupid Whirlpool and Lowes. Well I guess my plan for a tankless water heater just stepped up a notch. Company said it may be around $2700
adammb is offline Reply With Quote

Just because the T&P valve blew off does not mean you need a new water heater {however if it is 5 years old or older it is not a bad idea} The pressure valve is designed to release water if pressure or temperature gets too high. First check incoming water pressure anything over 80PSI incoming is too high and should be remedied with a pressure reducer. Secondly If the thermostats stuck, temperature overheats and the pressure relief will blow. Thirdly thermal expansion could be the culprit, in which case an expansion tank should be installed.

Now with all that said Tankless water heaters are wonderful, at least the gas ones. Rinnai makes the best IMNHAAO (in my not humble at all opinion), you can go to their website at
www.foreverhotwater.com
Don't let them sell you one that draws its combustion air from inside the house.. $2700 installed for a Rinnai R75 or R94 is not a bad price at all.
Big investment ask questions and do not get pressured into anything.

You mean the back area with the rack? Not completely following. Sorry.

I don't have experience with this, but it sounds like it would be worth the money to hire a structural engineer if you are seeing movement in your joists. Just my two cents...

One way to strengthen the joists is to laminate them to another joist. Basically you are doubling up the existing joist. Be aware though that if you have any sagging a nice new straight beam may not line up so well with the old one.

That being said, if you are building new walls and using new ceiling joists attached to the top of the new walls you shouldn't need clips. Instead build the walls shorter than the existing joists. That should give you the space you need to stay away from the existing floor joists.

adamm, you have a very nice room, try and post pics of the progress of your sound proof project, it will greatly help others in the community as well. My room is very similar to yours, especially the entry using the double (or french doors, whatever they're called). Unless sound isolation to adjacent rooms are not important to you, I'd say that you'd have to change the entry way to a different solution as well. I've thought about changing my doors to a sliding door that will give a better seal when closed. Seems like you're more concerned with the sound escaping to the rooms above.

Adam.. throw some additional photos up of the floor system when you get the drywall removed..

Based on limited info so far.. your room is 23 ft long.. and the information I can gather from the picture above is that they ran the joists parallel to the length...(although it does look like they sistered the joists)

Its hard to believe that they would have built it this way because this exceeds the defelction limits for nearly all dimensional lumber by more than just a small margin. (using machine graded 2x12 on 12" centers could have gotton "Close" to the 360 deflection limits)

Did they head off the joists (shown in the picture above) at a beam in the ceiling somewhere, Then change the direction of the floor system to run perpendicular to the room length? The soffit down the left side in the picture below suggests the joists are headed off at the right side of the fireplace otherwise the mechanicals would likely have been in the joist cavity....


Bridging can help.. you can also be selective on sistering additional supports without needing to get 20' lumber in your basement. (particullarly in areas where they cut to run mechanicals)

Throw up some additional pictures of your exposed floor system, its hard to "guess" whats going on up there..and difficult to help with suggestions...

Brad

Hard to believe it would have passed with the 23ft span.. and no other beams front to back.
Does it appear that a previous owner might have take out a support beam, or bearing wall, somewhere in the room length when the basement was finished? Possibly turning 2 smaller rooms into a larger room?

Brad

I'm no engineer, but I'd say either go with full 2x12's, attaching them with deck screws, then two lag bolts every 5ft or so depending on the length of boards you can get into the room, then attach the ends to the outer wall for more support. OR put a beam in the middle of the room going across the joists, with support polls at each end. I would think the latter is closer to code, but it might screw up projector placement.

I caught an episode of Holmes on Homes tonight. They had a similar problem to yours with regards to the floor. Mike added 3/4" plywood to each side of the joist and glued and screwed them together, overlapping seams on opposite sides. He said that this made the joists approximately 5 times stronger.

Now in your case you already have the joists laminated so I think I might try the bridge method as well.

When you say the joists "move", are they moving on the horizontal axis(side-to-side) or the vertical axis(up & down)?
If they're moving in the horizontal, you need to put bracing between them.
The most solid would be dimensional lumber, not cross bracing.
Make sure they do not contact the subfloor above as this could induce new squeaks.
Make them flush with the bottom of the joist and as an extra aid, put Liquid Nails on the ends that get nailed\\screwed.
If your getting flex in the vertical axis, do as someone mentioned above, glue and screw\
ail plywood to one side of the joists to stiffen them up.
Use screws or nails long enough to go through all of the lumber.
Personally, I would also replace the metal ducts with well insulated, good quality flex ducting.
Those metal ducts pick up vibration and act as a conduit for sound.

Adam.. Looks like you have plenty of room to work, the lack of mechanicals will make any modifications far eaiser. I'll echo some of the suggestions already made for improving the performance of your floor system, and throw in a couple of other options... Just depends on what lengths you want to go to..

Many of the same principals for soundproofing also apply to improvements in your floor and the "Bounce" you feel.. like mass, dampening and stiffness.

Ill throw this out quick before talking about your joists, just for something to keep in mind for the future..If you ever decide to change the flooring above this room, and you can stand and additional 3/4 inch, I would throw down an additional layer of T&G perpendicular to the original decking with a layer of GG in between.. this will help tremendously in further reducing "Bounce" and any impact noises in or sound out of the theater.

Although deflection and bounce are 2 different things, stiffness of the members impact both. So the goal is to increase the stiffness and deflection is a means of measuring this.. If I was looking at this, I would check to see the amount of deflection the joists have settled into under the current static load.. Eaisly done by pulling a string along the bottom side of the joists and measuring the deflection or "Sag" at midspan. the minimum IRC codes for living areas is L/360 and this would allow ~ .75 max, but in the real world this could still be a very bouncy floor and meet all codes. So assume we want a stiffer floor and go with an L/480 for deflection. This means we would want to keep the the "sag at midspan" under .5375 or basically a 1/2".

If the measurements were more than this 1/2" (particullarly on the spans down the middle of the room). Then I would seriously consider Supporting or "Jacking" up the joists close to midspan before doing any retrofitting..
Im not advocating a permanant post and beam(although a definate fix to the bounce issue) becasue I understand you are already concerned with height, but this is temporary while you make the improvements to your floor.

Note: depending on the amount of deflection your seeing and how much the joists have taken a "Set" this may need to be done over a period of time.. ie jack them a little at a time and let them set, then jack a little more.. let them set.. etc.. etc.. how much you move them at a time and how long they set will again be a function of how severe they are sagging now.. you'll need to make that call as you go.. you can continue to use the string along the bottom cord to see when your where you want to be. (I would reevaluate this if i had a tile floor above)

Now assuming we removed most or all of any sag that is present.. the first thing i see is (or dont see) in your pictures is that when they put the double joists in they didnt nail them in any manner that would be considered "Sistering" by normal standards.. this is typically done by nailing either 2 or 3 rows of 12-16D nails on 6-8" centers (typically 3 rows for 2x10 or wider) for the length of the joist. Even 2 rows on 12" centers would be an improvement .. If this is already done, and I just dont see them in the photos then disregard.

this lack of fastners probably contributes a signifigant amount to the squeaking you hear as the joists flex and move against each other..
(Ideally you would have also put construction adhesive between the joists)

As long as I was going through and adding the nail pattern to the joists, I would rip down some 3/4" Plywood just shy of the current joist depth and glue and nail it to the sides of the joist as IN2 mentioned. The minimal cost of the ply makes this an attractive retrofit.. you dont need to do this the full lenght of the joist but I would consider the middle 12ft as a min.. (alternating a 4' and 8' pc) you also dont need to do every joist, but the more the merrier.. every thing you do will add mass help stiffen your floor and reduce bounce.

Next I would use solid block Bridging at a minimun of the 1/3 span points, I would cut these from 2x10's with the goal of getting them to fit as tightly as possible within reason Try to avoid lumber with much moisture because you dont want shrinkage later to cause squeaks, it will be harder to nail but keeping the blocking in a straight line is better than staggering them, you can use construction adhesive as Milt said to help keep future squeaks to a min. This will help stiffen by transfering some of the loads to neighboring joists.

Another technique to stiffen the floor is to use metal strapping on the joists.
if you do this you want to do it before the blocking/bridging and while your floor is supported with the temporary jacks.. I looked today but couldnt find a picture of what I'm describing.. Using strapping like the simpson strong tie CS18 or CS20 you basically start the strap on an "Upper" end of the joist.. this strap then wraps down around the joist crossing the bottom at mid span and back up to the Upper opposite side of the joist at the other end.. critical factors when applying the strapping would be the size/type of fastners and making sure to keep the strapping tight aganist the joist as you go. What this does is help transfer some of the tension loading from the bottom and middle to the top and ends of the joists..

Sorry about the ramble ... you have alot of options to choose from.. some or many may consider it over kill, but probably what I would do hope this helps.

Brad

in the spaces with the ducts, just fit what you can above and below even if its just a 2x4

Sure it will help.. but Its hard for anyone to tell if the bridging alone will solve the issue.. how bad is the "Bounce" does it rattle things on the tables when you walk by or vibrate pictures on the wall? If it has bothered you in the past, now is the time to fix it before you put up your new ceiling. Maybe somone will chime in on an eaiser option.

Well....if you could get a structural engineer to come over and peek at it I bet the visit fee would be worth the advice. It ends speculation, provides a direct correction path, and most importantly you gain peace of mind for you and your entire family (including the wife ), not to mention any future owners of the property.

bridging helps a lot!

by locking the joists together you allow both joists to pick up the dynamic load of walking. Instead of bearing down on one joist at a time it is transfered to all connected joists. if you bridge the entire floor, all (even if just a small amt) of the load is spread accross all connected joists.

sister some 3/4" ply to one side and bridge with solid members every 4'.

to avoid the squeek on the floor caused by bridging add a bead of subfloor glue to the top of each bridge before hammering it home.

for the area's where you have duct work, you could bridge using engineered wooden i-beams with holes cut in the centere (allowed as per manufacturer).

also, a double drywall ceiling helps as well, as this further connects them all together. My living room floors were pretty bouncy until we finished the basement. we only did a single layer of Drywall on the basement ceiling but the bounce is just about all gone now.

good luck.