recommendation for turntable vibration damping

D_v:
I purchased a finite elemente Pagode Signature wall shelf. They are pricey (not as pricey as the next higher model in the line-up), but it was so worth it.

To your point, any wall-mounted shelf will provide a solid connection with the wall...but what if the wall vibrates? Well, this seies of shelves take measures to reduce the vibration transmitted to the shelf from the wall. Further, there is really a shelf that sits atop the "frame" (which then connects to the wall. The shelf is further isolated from the frame.

The next level up takes this even further. It's double the cost and I'm sure it's better...but the "Signature" model is pretty stellar.

Just something worth investing. Also, finite elemente include a mortar kit to shore up mounts into brick and concrete walls. Wow.

Thanks again, all, for your replies.

Even though the TT is now on the wall, I realized that I should still support the floor from underneath.

I like the automotive scissor jack route, atop a concrete block (and potentially below a 2'x2" or 4'x4").

The area I'm trying to support is 13'W x 10'D, with joists running from front to back and spaced 16" apart.

I'm thinking that instead of just supporting the equipment/rack and area under the 2 speakers, maybe I should just brace the whole floor.

Any thoughts on how many jacks I should use in that space?

How much is enough to barely get by (I'm guessing area under the rack + 2 speakers)? How much is enough to "do it right"?

Also, if I go the 2'x2" (or 4'x4") route, would you recommend 2 (or 4) jacks supporting each board?

Thanks so much for your thoughts.

I told ya!

..wall mounted shelves are the way to go. I'm so glad you are reaping your just rewards. ;)

about the floor-

Block it first!! Whatever you choose to do for a pier, put a healthy amount of cross-blocking in between the joists first (say...every 2-3'. staggered) and I bet that makes a huge difference all by itself. Be sure to use the same dimensional lumber your joists are and be sure the wood is pressure treated.

I would do this: In an area where you have pre-selected to brace with a pier- drop a plumb line down into the soil and excavate a hole with a foxhole shovel that is below the frost line (whatever it is in your area) by at least a few inches and approx 2' by 2' square. Drop a large 18" by 18" patio stone of compressed concrete in the bottom of the hole and level it. Cut a piece of 6X6 PT lumber post that is exactly as long as the top of the stone to the top of your joist and then cut a notch in the post to accomodate your joist. Carefully tap the post in place and drill a 3/8" hole horizintally through the post and joist join and install a galvanized cairrage nut/bolt with fender washers. Double check for plumb and then tighten the nut. Back fill the hole and tamp it hard. 1 of these piers in the right location (after you have installed plenty of blocking) will make your floor rock solid. You can always add as many as you like- but 1 good one should be PLENTY for a room your size.

Thanks, Valve & Vinyl.

Dumb question: Does "blocking" refer to connecting joists with shorter pieces of wood (16" apart around here)?

The blocking could be hard to accomplish given that I just installed insulation between all joists.

I also may have screwed up because I didn't see your post before hitting the hardware store today.

I purchased a 4"x4"x8' and 2 adjustable floor joist jacks (the local hardware store only had 2) such that they are near the minimum of their range. I positioned the 4x4 so that it was perpendicular to the joists (it's supporting 6 joists). I used the jacks under the 4x4. I figured I would see how well it worked and then add more if necessary (I would need possibly 2 4x4x4' & 1 more 4x4x8' to cover it, given the pipe situation).

Does the method you suggested (hole + patio stone + pier) replace what I did above? It sounds like it does...and it sounds like a more elegant solution.

Should I not add the 2-3 additional 4x4's w/ jacks? The jacks (36") are like $30 a pop.

Thank you!!!

Hi,

Lumber isn't cheap either. I just put in a new deck 12' X 12' and even though that's pretty small- it set me back nearly $2K. Ouch.

Yep- blockling is putting in a piece between the joists (or studs).

The only problem I see with your joist jack method is that you are at the mercy of nature, in that you will probably need to re-adjust it often because of heave and expansion/contraction. A jack like that indoors remains fairly stable; When it's exposed to temperature outdoors....

When a builder puts in a bathtub, stairwell, or anything else that requires either a cut-out in the joists and/or extra bracing, the common method is to add blocking. It may not seem like it would add a significant measure of support but it certainly does. When the joists are allowed to flex independently of each other- they do. When held to the rigidity of its neighbors (other joists)- they don't. Pretty simple.

Use whatever type of column you wish, but I would still block the joists to the hilt. If you recently added insulation, you could just make a header or horizontal beam to distribute the load of your column of choice. This could serve to replace the blocking (sorta). Make sure you toenail the beam in an X wherever it meets a joist though. I'd double up (sister) a 2X6 (at least) for your header/beam. 2X8 would be better. I'd put two columns (per beam) if doing this method.