laminate before drywall?

Is this a bad idea? Im using sound clips and hat channel and was thinking that increased isolation would be achievable if the edge of the drywall (the neoprene pads actually) sat on top of the laminate. Perhaps a tighter seal as well. This may be a dumb question. My concern is the planks bowing up at the edges from the weight of the drywall. I also realize the risk of damaging the floor during drywall phase. Did I just talk myself out of it? thx

dubwise wrote:

Is this a bad idea? Im using sound clips and hat channel and was thinking that increased isolation would be achievable if the edge of the drywall (the neoprene pads actually) sat on top of the laminate. Perhaps a tighter seal as well. This may be a dumb question. My concern is the planks bowing up at the edges from the weight of the drywall. I also realize the risk of damaging the floor during drywall phase. Did I just talk myself out of it?

I'll try to talk you out of it - but not for either of those reasons. The idea behind an assembly of this type is that the drywall is decoupled from the surface of the structural frame. In order for this to work properly (to achieve the maximum isolation levels offered by the product) it is very important that the drywall surface floats - you do not want it tight to anything - not to the ceiling - not to the walls where they meet at the corners with other walls - and not at the floor. You want to install everything so it is able to move freely - and interlock the corners so that you create a path the sound would have to follow (in the corners) with backer rod and caulks to create the seal. At the floor you should hold it up about 3/8", and install backer rod and caulk. The laminate floor also needs the chance to move - and should be installed about 1/2" away from the walls all around - caulking that seam is not really required if the walls are properly sealed. The baseboard finishes will cover the exposed joint between the wall/floor. Rod

Thanks, Rod. That all makes perfect sense to me except for one statement I'm a little unclear on......

At the floor you should hold it up about 3/8", and install backer rod and caulk.

Are you saying that I should not rest the drywall on neoprene pads at all, rather suspend it completely off the surface of the floor by 3/8" and fill in with backer road and caulk? I always figured that the floor needed to support the drywall when using clips and channel. Is that not the case? Thanks for the great info.

dubwise wrote:

Thanks, Rod. That all makes perfect sense to me except for one statement I'm a little unclear on......

At the floor you should hold it up about 3/8", and install backer rod and caulk.

Are you saying that I should not rest the drywall on neoprene pads at all, rather suspend it completely off the surface of the floor by 3/8" and fill in with backer road and caulk? I always figured that the floor needed to support the drywall when using clips and channel. Is that not the case?

That is not the case......

So then as I understand it I am doing the following around the entire perimeter of the room where the drywall meets the floor. 1. shim the drywall at 3/8" 2. fasten the sheet(s) to the channel 3. remove the shims and fill the space with backer rod and caulk Is this the correct order of operation?

"3. remove the shims and fill the space with backer rod and caulk" Maybe...but it might do better to install the backer rod as much as possible, then remove the shims, then fill the void left by the shims to minimize the potential for any bridging of the sheetrock to the slab via gravity.

Yeah that's a good point. Ill definitely do that. Is it crucial to use backer at the vertical joints as well? Thank you. All this has been really helpful.

dubwise wrote:

Yeah that's a good point. Ill definitely do that. Is it crucial to use backer at the vertical joints as well? Thank you. All this has been really helpful.

If the clips and track are properly installed you could never get 3/8" of sag - in fact with 2 layers of 5/8" drywall you could not get that with RC-1 properly installed. I would not worry in the least about removing the shims prior to installing the backer rod. And if the systems were not installed properly - if a wall panel was going to settle to the floor, it would have enough mass to simply crush the backer rod tight to the floor anyway - the system in that case would be worthless - the least of anyone's worries would be backer rod and caulk. It is crucial to use backer rod and caulk at all corners - so wall to ceiling - wall to wall Rod

Wrong word I used, bridging. I was thinking, having never experienced this before, that there will be some amount of sag once the load was transferred to the rc and that there would be some bit of a downward move. For that reason only, rather than have to push the backer rod in with a 5-n-1 tool or what have you, it would be easier to slide it into place before any compression was involved. So, sorry about that :)

Great thread! When reading I was wondering about finish work/trim work along baseboards once drywall, backer rod and caulking is completed. I was assuming the addition of some wood trim to cover caulked/backer gap where floor and walls meet would be of negligitable impact. Any special tips for this kind of finish work or is just standard finish nails/adhesive fine?

Johnny Corvette wrote:

Great thread! When reading I was wondering about finish work/trim work along baseboards once drywall, backer rod and caulking is completed. I was assuming the addition of some wood trim to cover caulked/backer gap where floor and walls meet would be of negligitable impact. Any special tips for this kind of finish work or is just standard finish nails/adhesive fine?

With a wood floor generally the baseboard is installed - and then a shoe molding - in the case of a wall system that is mean to float freely the best method would be to attach the base to the wall (however you wish)- holding it up slightly (1/4 to 3/8") above the finished floor and then fasten the shoe molding directly into the flooring itself. With a concrete slab I would just glue the base to the wall to allow for any slight bit of settlement that might take place (this would be movement over time of the framing itself - the drywall is very stable). Rod

Ended up using 3/8 shims and removing them before adding 1/2" backer rod under the first layer. As of now the backer is just snug enough to stay in place. Layer 2 will have green glue. Im thinking any sagging would happen then.