Can new carpet go over old pad?

Why the question comes up at all

The cushion is the one part of a carpet job nobody has looked at since the day it went in. Peel a corner back in a closet and it generally appears whole, dry and more or less clean, and keeping it looks like the sensible move. The carpet is the part that wore out. The pad, apparently, did not. That reading is understandable and it is almost always wrong, for reasons that have nothing to do with selling cushion. What genuinely moves a carpet quote is set out on carpet cost factors.

What the cushion does mechanically while the carpet is down is a separate question with a page of its own, and this one does not repeat it. This page is about the specific idea of keeping the one already there.

It has already taken the shape of the last carpet

Cushion takes a compression set. Wherever people walked it is now permanently thinner than it is under the sofa that has not moved in a decade, and the difference is not subtle once you are looking for it. Roll new carpet over that and you have laid a flat thing across a floor that is no longer flat. The old lanes start reading through as shading and as slightly lower ground. The last carpet's traffic pattern outlives the last carpet.

The other half of it is resilience. A cushion that has stopped springing back has stopped doing the job it was there for, which is taking the impact of a footstep before it reaches the carpet's backing. The new carpet then absorbs loads it was never meant to take on its own, and backing is what gives out when that happens.

And it holds everything that went into it

Whatever soaked through the old carpet is in the cushion: spills, pet accidents, years of fine dust no vacuum ever reached, and on a lower level whatever a damp season put there. Fitting new carpet over that is putting a new lid on the same jar. It is also the most common explanation for a household that installs new carpet and still smells the old problem, which then gets blamed on the new material. A genuine new carpet smell is a different thing and it fades. What is in the old cushion does not, and if animals are part of the picture, the pet carpet page is worth reading first.

Most of it does not survive being uncovered

This is the part that settles the argument in practice rather than in principle. Cushion is stapled or glued down in strips, and years of pressure bond it to the carpet backing sitting on top of it. When the old carpet comes up, a good deal of the pad comes with it in pieces, leaving torn edges and its own staples behind. The clean, intact, reusable pad rarely survives contact with the removal.

What the floor looks like once it is all off

Taking up an old carpet is the only time anybody sees the subfloor, and it is worth using. Old staples have to come out or they telegraph through the new carpet. The tack strip around the perimeter gets checked and often replaced, because pins rust, bend, and were set at a gauge suited to the carpet that just left. Squeaks can be found and fastened while the deck is open. Stains from old accidents show where they actually travelled. Soft spots and moisture get discovered at this point rather than a year later.

Taking out the old carpet, the cushion, the staples and the tack strip is real work that happens before anything new goes down. What is included on a given job gets settled at the free in-home measure, along with seam placement and what needs clearing out of the room beforehand. The order the rest of it runs in is on our installation process page. Call 636-332-0654 and ask.

The narrow case where the question is fair

If the cushion genuinely is recent, is the specification the new carpet calls for, is dry, still springs back when pressed, and comes through the removal intact, an installer can look at it and say so. That is a judgment made in the room with a corner pulled back. It is not one anybody can make down the phone or from a web page, and it is not the usual outcome. The cushion a carpet wants under it is set by the manufacturer of that carpet rather than by whoever is fitting it, which our carpet page covers. And if you are still working out whether the carpet needs replacing at all, start with the signs a carpet is finished.