Guide · For the trade
Felt rug pad for hardwood floors: thickness, density and what to specify
A felt rug pad is the pad to specify under an area rug on hardwood: 1/4 inch felt with a natural rubber face for rugs that can move, 3/8 to 1/2 inch 100 percent felt for large rugs anchored by furniture, at a density of 32 to 40 oz per square yard, cut 1 inch inside the rug's edge on every side. Natural rubber and needle-punched felt do not react with polyurethane or oil floor finishes; the PVC and plasticized pads that discolor hardwood are the ones to keep out of the spec.
This guide is for the designer or the junior writing the pad line on a rug order for a hardwood, engineered, LVP or tile floor. It covers what the thicknesses and densities on a pad spec sheet mean, felt versus rubber versus felt-and-rubber, what is safe on a finished floor, sizing and placement for the installer, and the questions clients ask.
What a felt rug pad is, and what the numbers mean
Rug pad felt is a needle-punched mat of recycled synthetic fiber, sometimes with wool, compressed to a stated thickness and density. Thickness is the cushion; density is the support and the number that matters, because a thick, light pad collapses under a sofa leg and a dense thin one does not. The trade pads run 20 oz per square yard at the light end to 40 oz and more at the dense end. A 100 percent felt pad has no grip of its own; a felt and rubber rug pad bonds a thin natural rubber layer to one face so the pad holds the floor while the felt holds the rug. The rubber side goes down. The rug pad thickness guide covers the thickness question across all pad types, and the carpet pad types guide covers pad under wall-to-wall, which is a different product.
Felt, rubber or felt and rubber: which under which rug
| Pad | Thickness | Density | Grip | Specify it under |
|---|---|---|---|---|
| Felt and natural rubber | 1/4 in (also 3/8 in) | 32 to 40 oz per sq yd felt layer | Yes, rubber side down | Most rugs on hardwood: hand-knotted, hand-tufted, hand-loomed, bound broadloom, 5x8 to 10x14 |
| 100 percent felt | 3/8 to 1/2 in | 32 to 40 oz per sq yd | None | Large rugs held in place by furniture, 9x12 and up; rugs the client wants plush underfoot |
| Thin natural rubber | 1/16 to 1/8 in | Solid or waffle rubber | Yes, both faces | Flatweaves, kilims, dhurries and runners in doorways where a thicker pad would trip or stop a door |
| Felt and rubber, 1/8 in | 1/8 in | Dense | Yes | Braided and reversible rugs, low-clearance doors, stair runners over wood (with a dense 1/4 in alternative) |
The decision is grip first, then cushion. If anything about the rug or the room can make it move (a flatweave, a runner, a rug in a path, a rug with only a coffee table on it), the pad needs rubber. If the rug is a 9x12 under a full seating group, 100 percent felt at 3/8 or 1/2 inch gives a softer walk and the furniture does the holding. The rug slipping guide covers the cases where the rug still moves.
What is safe on a hardwood, engineered or LVP floor
Natural rubber and felt do not stain or soften a polyurethane, oil, wax or UV-cured finish. The pads that cause claims are the open-mesh PVC and plasticized rubber pads sold by the roll: the plasticizer migrates into the finish and leaves a yellow or tacky ghost in the rug's footprint. Avoid any pad described as PVC or whose rubber feels oily. Felt and natural rubber are fine on LVP, laminate and tile as well; on a radiant-heat floor keep the pad at 1/4 inch or thinner so it does not insulate the slab, and see the carpet over radiant heat guide. On a freshly finished hardwood floor, wait the finisher's cure time (usually 7 to 30 days depending on the finish) before any rug and pad go down.
Sizing the pad: 1 inch inside the edge
The pad is cut 1 inch inside the rug's edge on every side, so the pad is 2 inches shorter and 2 inches narrower than the rug: a 9x12 rug takes a 8 ft 10 in by 11 ft 10 in pad. The rug's edge then tapers to the floor instead of sitting on a shelf. For a thin flatweave the pad is cut 1/2 inch inside. Add the pad to the rug order and we size it to the rug; for a custom or bound rug the pad is cut to the same template. An 8x10 felt rug pad under an 8x10 rug is wrong by exactly 2 inches and is the usual reason an edge curls.
What to tell the installer
- Pad type, thickness and density as written on the order, and the rubber side down.
- Pad cut 1 inch inside the rug edge all round, trimmed on site if the rug's finished size differs from the drawing.
- No tape on the floor. A felt-and-rubber pad holds without it; if the rug still moves, the fix is more rubber, not adhesive on a finish.
- Check door swing. Rug plus pad over 3/4 inch at a door means the door is undercut or the pad at that edge drops to 1/8 inch rubber.
Thickness by rug construction
Under a hand-knotted, hand-tufted or high-pile wool rug, 1/4 inch felt and rubber. Under a bound broadloom rug, 1/4 inch felt and rubber in a path and 3/8 inch 100 percent felt under a seating group. Under a flatweave, 1/8 inch rubber. Under a sisal, jute or abaca rug, which slides, felt and rubber at 1/4 inch, never plain felt. Under a rug on top of carpet, a different pad, covered in the rug on carpet guide.
Questions designers ask
Is felt a good rug pad?
Yes, and it is the standard under rugs on hardwood. Dense needle-punched felt at 32 to 40 oz per square yard protects the floor, quiets the room and extends the life of a hand-made rug by taking the grinding of the knots against the floor. On its own it has no grip, so it is for rugs held by furniture; with a rubber face it is for everything else.
Which is better for a rug pad, rubber or felt?
They do different jobs. Rubber grips; felt cushions and supports. For most rugs on hardwood the answer is both in one pad, felt and natural rubber at 1/4 inch. Choose plain rubber only under thin flatweaves in doorways, and plain felt only under a large rug the furniture already holds.
What is the best pad to put under a rug on hardwood floors?
A 1/4 inch felt and natural rubber pad, cut 1 inch inside the rug's edge, rubber side down. It is safe on polyurethane and oil finishes, holds the rug, and supports a hand-knotted, hand-tufted or bound rug without the edge curling. Move up to 3/8 or 1/2 inch 100 percent felt under a large rug the client wants plush.
Which side of a felt rug pad goes against the floor?
The rubber side, on a felt and rubber pad; the rubber holds the floor and the felt holds the rug. A 100 percent felt pad has no face and goes either way. If the installer puts the felt down on a felt and rubber pad, the pad grips the rug and slides on the floor, which is the opposite of the point.
Browse: rug pad thickness guide · rug slipping guide · rug on carpet guide · hand-knotted rugs · custom rugs