[gitarretyp]

I'm currently renting a house with rather springy suspended wood floors. I have my speakers and subwoofer on isolation platforms, but i'm not terribly happy with the setup. I want to add some support to the floor under my equipment and wanted to use Lally columns, but no one in Austin i've spoken with has even heard of them much less sells them. Are there any solutions better than simply hammering a 2x4 between the floor joists and the ground? Please keep in mind i'm renting, so no major structural changes .

[mjosef]

Home Depot carries a 3" metal lally column for about 15$, at least they do in the NY stores...but should be available at any serious building supply hardware store.

[Levi]

Would the metal lally column work on NYC apartment with wood subfloor?  Hmmm...

[andyr]

I'm currently renting a house with rather springy suspended wood floors. I have my speakers and subwoofer on isolation platforms, but i'm not terribly happy with the setup. I want to add some support to the floor under my equipment and wanted to use Lally columns, but no one in Austin i've spoken with has even heard of them much less sells them. Are there any solutions better than simply hammering a 2x4 between the floor joists and the ground? Please keep in mind i'm renting, so no major structural changes .

Being an Aussie, I've absolutely no f'ing idea what a "Lally column" is but I presume you have underfloor access?  I appreciate that as it's a rental place, you don't want to spend up big ... but hammering a 2x4 between floor joists and ground is not going to be very satisfactory (as I suggest the ground will just compact).

So why don'tcha dig a hole underneath the floor joist where you want to support it - or more than one hole if there is more than one vital joist or the joist needs more than one support.  Take the hole(s) down as deep as you can ... and fill it/them with concrete.

Then lay bricks in a square "pier" format on the concrete.  Before you lay the final course, hire a couple of jacks so you can lift the joist(s) slightly to get the bricks in ... so when you slack off the jacks (after the mortar is dry), the joist(s) settle(s) on the pier(s).  And don't forget, if Austin, Tx, is a termite-prone area, to put a cap between the top of the brick pier(s) and the joist(s).

Voila!  A firmly supported joist!   

Regards,

Andy

[JLM]

If the walls are sturdy you could bracket off of them with wall brackets used for countertops to support the equipment.

If that doesn't seem renter friendly enough, try hanging the equipment from the ceiling (if it's an attic and so wouldn't have neighbors footfalls to consider).


For your speakers and sub, the Aussie is right    If you go down under the support will need some sort of foundation lest it will settle and be of no value.  Concrete floor slab would be great, a couple pieces of treated lumber 2 x 12 x say 18 inches long nailed together would probably be enough if the soil is dry.  If the soil is suspectable to moisture I'd buy a bag of ready-mix concrete, lay it down where you want, cut the side pointing up, add water, and "set" a 2 x 12 x 12 inch long piece of treated lumber into the top of it.  Before doing the treated lumber/concrete be sure to remove anything with organic looking material (like potting soil) that can decay.  Then attach the lally column.  All this could be removed when the lease is up.

Andyr, a lally column is a 4 inch diameter pipe with a 3 inch diameter pipe inside.  They have holes drilled so you can slide them in and out to adjust for length and then bolt through.  They also have a large threaded rod at the top for fine adjustments.  And they come with pre-drilled top and bottom plates for nailing.  We use them to support floor girders in residental construction.

Wooden floors are notorius for resonanting, especially under crawl spaces.

[andyr]

Andyr, a lally column is a 4 inch diameter pipe with a 3 inch diameter pipe inside.  They have holes drilled so you can slide them in and out to adjust for length and then bolt through.  They also have a large threaded rod at the top for fine adjustments.  And they come with pre-drilled top and bottom plates for nailing.  We use them to support floor girders in residental construction.

Thanks for the explanation,JLM.

Regards,

Andy

[Levi]

Thanks JLM for the explanation.

[Charles Calkins]

What a coincidence!!
 I was at my digital guru's new house yesterday to pick up my CD player that he just finished upgrading. His audio studio is above a detached garage. Very nice room and excellent sounding audio gear. The floor in the room is also springy. Rather than go through a lot of expensive remodeling to get the spring out of the floor he went to Home Depot and bought brick paving stones to support his audio gear. The paving stones under his speakers are about 16"W X30"L X1.5"H. The others are smaller and are used to support smaller audio gear. Hey!! Works for him and it's an easy and cheap way out.


                                            Cheers
                                            Charlie

[DeadFish]

Man, you can tell its winter.  Folks are fixing stuff up inside! 

My ol' house is 100 plus years.  Living room is just short of a trampoline and I've played with it for years for less bounce to the ounce, but not done all that well with the old joists sometimes being split.
 
For examples:  I had my gear across one outside wall (above the brick foundation) but still couldn't play vinyl without going nuts anytime anyone moved in the room.   Put a 4x4 across the bottom of the joists with 2-3 steel support columns under it (with concrete floor there), but it was not all 'that' for fixing it.  I put 1-2 2x6 on every floor joist, completely across, nailed every 12 inches.  It was some better, but still, no joy. 
The ONLY way I got the turnatble stable was directly in corner of the room, where there were supports under both walls.  I considred a wall mounted stand, but didn't want to mess up my plaster or face another failure after I had spent the money for corner-shelf.
Eventually, I moved it to a system in newer part of the house.
I live with the spring that is left, tired of it rubbing my nose in what I couldn't fix.  It works good enough for cd and squeezebox listening.
I also considred 'loading' the floor with a buttload of weight so it would have a downward sway that merely walking across the floor wouldn't budge.  Again, easier to move...

Hopefully, the method Charlie described will do you for less-than 'turntable bounce'.

Good luck!  Let us know if you have divined a more successful method!!

Regards,
DeadFish

[Charles Calkins]

DeadFish:

 My guru has a turntable mounted on a stand and the stand sits on top of a brick paver.


                             Cheers
                                Charlie

[DeadFish]

DeadFish:

 My guru has a turntable mounted on a stand and the stand sits on top of a brick paver.


                             Cheers
                                Charlie

Yah, I tried that too, Charlie, with all my gear on the stand and the legs filled with 2 bags of lead shot. 
Maybe I was just tracking too light, or the floor joists were made out of 'jumping juniper'! 

I've been a headstrong 'bastid' in my day, and at the time it was tough to just give up. 
Then again, I can look at it that it propelled me to develop my attic room for listening, where it gave me more room and an ultimately better listening experience.  I even built stairs up there just to get the big-ass speakers up there!  Wouldn't have done it otherwise.

Rather than beat my face pulpy with problems anymore, I've taken more of the attitude of "If Life gives you lemons, buy some tequila!!"
 

Best Regards,
DeadFish

[Charles Calkins]

Tequila???? Did somebody say Tequila???

[EProvenzano]

I've added bridging blocks to good effect.  These help the joists act in unison giving the floor added rigidity.  It's not as effective as adding a tele-post but it's cheap and easy.

Bridging def:
Small pieces of wood or metal strapping placed in an X-pattern between the floor joists at midspan, adding strength, and preventing the joists from twisting and squeaking.

[mjosef]

FWIW, if the whole floor span is bouncy, X-bracing will not help much, the floor joists were probably not sized correctly for the span, you will need to shorten the span with columns and wood blocks. Figure a column every 5 feet or so. A perpendicular cross-joist supported by the columns.