Should my stage and riser go on Dricore?

I think the general consensus is the stage should go on the dricore. I did delta FL on my floor and installed the stage on the subfloor. Getting the sand filled stage off the concrete was one of the big things that made me decide to do a subfloor. I figured having something like the dricore to prevent all that sand from getting wet in the event of a small leak would be worth it.

Having the stage on the concrete in the event of a BIG leak is worth it. If you EVER have to remove the dricore, good luck getting it out from under the stage. And I'm speaking from experience.

If you line the inside of the stage with plastic, your sand shouldn't be getting wet unless the flood is over the top of the stage.

You have to cut them anyway. Just start from inside the perimeter of the stud wall instead of the perimeter of the foundation wall. It will probably work out to the same number of tiles. You'll just be cutting a little more or a little less off the end ones. Unless your room was a perfect multiple of the tiles + 1/2" from the recommended spacing form the walls. The tiles are not EXACTLY 2 feet across. They're a little less.

That, or use pressure treated for the bottom plate. There are rolls of pink plastic-looking stuff that's 3 1/2" or 4" wide designed to go under 2x4s.

Also, do yourself a fave and use double bottom and top plates if you are going to use double drywall. Remember, a 2x4 is really 1.5 X 3.5. The dricore is 7/8s inch. That doesn't leave much of a nailing surface at the bottom the wall. And if you are doubling the ceiling with 5/8, it doesn't leave much of a nailing surface at the top, either.

If you have a leak that is enough to get the dricore wet aren't you going to have to remove the stage and sand anyway?

Has there been any consideration of the effects of either approach on sound isolation? I can't imagine there have been any lab tests but maybe some educated opinions on this?

I did not. I lined the stage cavities with plastic before filling with sand. The weight of the sand created a seal against the concrete (why do you think they use sand bags during a flood?). I used 2X8 for the frame, even the curved front. I got the water out within and hour, so it was damp, but not soaked. Everything dried out fine.

Build the stage so that it is not touching any of the walls. That decouples from the walls. About 2.5 tons of sand adds, well, TONS of mass. Concrete is extremely stiff and therefore conductive, but your subs have to move 2.5 tons of sand first. And the sand has room in between all of the little grains to vibrate and absorb energy.

I would reckon you would get a certain amount of decoupling from the concrete by building on the dricore, but I would suspect that you would feel in the floor.

THIS!!!!!!

I had to cut and install small blocks between the wall studs to having something to screw the walls onto due to the ceiling being so much lower with DD, clips, and hat channel. Was a pain. Using two boards instead of one for the header would have made my life simpler.

There is no need to screw along the top and bottom edges between studs when hanging Rock on a studded wall. Just hit the studs close to the top and bottom.

You guys are just creating extra work for yourselves.

However, I would think that for attaching baseboards and/or crown moulding, you would still want the nailing surface.

But that DOES explain why I PAID to have my drywall hung.

One way to minimize cuts on the dricore that will go against the stage is to build the stage in sections.

Often the stage in is built sections anyhow. So build 2 big sections for the width of the room that goes directly on the concrete of whatever depth you require for standing speakers, subwoofer etc. something like [_____||_____] Then do the dricore up to that front edge. Then on top of the dricore do the rest of the stage, steps, curves, etc.

I approached it this way and with about 4 inches of water at one point I was glad I did. Saved money on the dricore in that section before and after. As Tom said, properly lined with plastic will keep the sand dry unless it flows over your stage height all together. At that point the sand is the least of your worries.

BTW I also did the same thing for the riser, but it is one section the width of the room. The steps are then added on top of the dricore.

Crown is usually attached well below a double top plate in DDW construction, Nailing the baseboard to just the studs works.

There are other reasons to use a double top plate, attaching drywall and crown isn't among them.

So what are the other reasons?

If the top plate spans a long distance under ductwork and is only secured on the ends, using a double plate will stiffen the wall.

From another thread I would have used a double on the right side in this picture.



If you are going to need to big notches in the top plate for a low hanging pipe it might make sense to use a double so that the lower one is intact.

Just trying to think outside the box here, but if you're really concerned about your basement flooding, couldn't you pour a small "footing" or pad on top of your slab that's the same height as your Dricore (or whatever height you want I suppose), and the same outside dimensions as your stage or riser, that's wide enough for a 2x to rest on. Something like a 4" wide pad that runs just inside your walls and straight across the front. It would need to be wide enough to put an anchor in without cracking. Then your safe to set your perimeter framing on the "footing" knowing it will be high enough to prevent the stage from getting wet. As mentioned before, you line the cavity with plastic before filling with sand to keep any moisture permeating the concrete from saturating your sand.

It would be a cold joint, so if you ever decided to take it out, it should break off pretty easily leaving your original concrete floor behind.

Ok, feel free to shoot holes in this idea