Additional underlayment?

[mpoland33]

HEllo! We are all set to install Pergo Outlast plus linton oak color. Anyway, it comes with underlayment alreaady. As a hope for some additional sound proofing, CAN I install an additional underlayment directly on top of the level plywood? Everything I read said it is not "required" but I havent seen whether you are allowed.

THanks!

 

[mpoland33]

Oh I got an additional question. It was recommended I use Pergo Floormate as an additional underlayment....has anyone used that? The question I would have is 1. do you think yes or no? 2. would this take place of a wood underlayment? Currently on top of the plywood they appear to have an underlayment wood, luralie or something like that. I'm hoping its in good shape and re-usable but ready to remove it if I have to.

 

[highup]

I'm not familiar with the pergo Outlast product, but I know some products such as cortex can be purchased with or without an attached underlayment. The underlayment is not a cushion. It's for sound deadening and so the product doesn't clatter against the floor that you're putting it on. It has nothing to do with making the floor softer.
If this flooring has an attached underlayment or cushion, then I would definitely say to not add more. These type of floorings have interlocking joints that mesh together. Adding more cushion makes the joints flex. Flexing of these joints cause the joints to weaken and sometimes to the point of making the individual rows of material detach or move back and forth. Most all manufacturers have a technical line to ask for assistance. I would definitely call pergo ask for their tech line and tell them your exact product number and ask them for advice.

 

[highup]

Let me add something additional after rereading your questions. Don't be confused by underlayment. Plywood underlayment and the underlayment for pergo Outlast or any type of floor like that are not related in any way shape or form.
Underlayment for click type vinyl flooring is to make the product sound nice when you walk on it. It dampens the sound of hard sould shoes and the transmission of sound as you walk on the floor.
Plywood underlayment is designed to separate the subfloor joints from the floor covering.
If you have a 3/4 in sub floor in a new home and add one quarter inch thick plywood underlayment on top of that, you will stagger the seams in the underlayment plywood so that the upper layer seams are not directly over the sub floor seams. This keeps movement of the subfloor seams from telegraphing onto the finished product which is often a vinyl floorstaggering the joints between the subfloor and the underlayment make the floor stronger and makes the seams of the underlayment less able to shift or move.
The type of underlayment that is on or recommended for Pergo Outlast, or any other click lock type of flooring is only for the suppression of sound as it's being walked on.

 

[mpoland33]

Ok thanks. I will definitely call them. Currently, I believe (and will confirm this weekend when I tear out the carpet in the first room) that they have Luan down underneath the carpet. I'm hoping since the floor is only 13 years old, that this is still in good shape and is re-usable. Because of my squeaking issues, I had someone recommend putting another 3/8 sheet of sanded plywood down as hoping to quiet the squeaks in addition to adding screws, etc. But the underlayment I'm talking about is just the one that Pergo makes. The outlast comes with the backing already and this type of underlayment is the only one Pergo will allow to put under and keep the warranty. The main reason for the underlayment is a bit of a sound barrier for underneath (my next project is finishing the basement and I want to do all I can to minimize noise underneath) and for minimizing sound walking on it as far as hollowness or something like that.

 

[highup]

If the floor has squeaks you should be able to get rid of that without adding additional underlayment. The squeaks are coming from the fasteners and if they weren't nailed in well or the floor joists shrunk and loosened the fastener it would take a very tiny amount of movement to make a squeak. You need to find out where the floor joists are and drive in a couple of screws. Sometimes it helps to have a second person to sort of bounce up and down on the area where this week is while you have your ears down by the floor. You can often pinpoint very close to the squeak location. The squeak is usually on a joist. If it is, you'll need to add a screw that goes into the joist to pull the underlayment tight.
It gets confusing sometimes with these floors using the term underlayment.
The subfloor such as OSB or plywood is put on top of floor joists. If there's a second layer on top of this one let's say because you need to install vinyl flooring. The second layer is called underlayment. The cushion or padding is sometimes referred to as underlayment also.
If the pergo Outlast comes with its own padding or underlayment, then I doubt that pergo would allow you to put in an additional layer of that type of underlayment.
So basically if there are no major issues with the Luan plywood underlayment, if that's what you have, then I don't think it would help any to add another layer of plywood. It's just adding a lot of extra expense as plywood isn't cheap. You really just need to find the source of the squeaks.
But again talk to the pergo technical people and ask them questions about the underlayment.

 

[Csason]

Lately manufacturers have been squawking about laying plastic between clic floors and concrete since they want to blame problems on moisture. Problem is you put too much crap under the material and the joints have too much non support under them and come apart . Use a professional. Save money