Key Takeaways
| Factor | Consideration |
|---|---|
| Grout lines | Will telegraph through thin carpet—use dense underlay |
| Tile condition | Loose or cracked tiles must be repaired first |
| Height transition | Carpet adds 1–1.5 inches—requires transition strips at doorways |
| Adhesive | Use concrete adhesive for tack strips—tile is too hard to nail |
| Subfloor | Tile is a hard, stable surface—ideal for carpet |
| Reversibility | Easy to remove carpet without damaging tile |
Why Homeowners Install Carpet Over Tile
Tile is cold. Ottawa winters make tile floors unbearable without heated floors underneath. Carpet adds warmth without the cost of radiant heating installation.
Tile is hard. Families with young children or elderly members want a softer surface. Tile offers no give. Carpet cushions falls.
Tile is noisy. Footsteps echo. Dropped objects clatter. Carpet absorbs sound—critical in condos and townhomes where noise travels between units.
Some homeowners inherit tile they dislike. Removing tile is destructive. It damages the subfloor. It creates dust. It’s expensive. Carpet installation over tile is faster, cheaper, and reversible.
The tile stays intact under the carpet. When you’re ready, you pull up the carpet and you have tile again. No demolition required.
How Grout Lines Affect Carpet Appearance
Grout lines sit lower than the tile surface. Standard grout lines are 1/8 to 1/4 inch wide and 1/8 inch deep. Thin carpet and underlay will conform to the grout lines. You’ll see a grid pattern through the carpet.
Dense underlay minimizes this. Rubber underlay or high-density synthetic underlay bridges the grout lines. The carpet sits on top of the underlay without dipping into the grooves.
Thick, plush carpet hides grout lines better than low-pile carpet. Berber and commercial-grade carpets are thin. They show every imperfection in the subfloor. Saxony and frieze carpets are thicker and more forgiving.
If your tile has wide grout lines (1/4 inch or more), consider applying a skim coat of self-leveling compound over the tile before installing carpet. This fills the grout lines and creates a smooth surface. The compound costs $30–$50 per bag and covers 50 square feet at 1/8-inch thickness.
For most residential installs, grout line visibility is minor. Dense underlay and medium-pile carpet will conceal it.
Securing Tack Strips to Tile
Tile is ceramic or porcelain. It’s harder than wood. Nails don’t penetrate. You need adhesive or masonry screws.
Concrete adhesive—the type used for gluing tack strips to concrete slabs—works on tile. Clean the tile surface with alcohol or degreaser. Apply adhesive to the back of the tack strip. Press it down around the room perimeter. Let it cure for 24 hours before stretching the carpet.
The adhesive bond is strong. Removing the tack strips later may pull off chunks of tile glaze. Test a small area first if you’re concerned about damaging decorative tile.
Masonry screws are the alternative. Pre-drill holes in the tile with a carbide-tipped masonry bit. Insert plastic anchors. Screw the tack strips into the anchors. This method is more secure but takes longer. It also creates permanent holes in the tile.
For most installs, adhesive is sufficient. Use a high-strength construction adhesive rated for concrete and tile. Avoid silicone-based adhesives—they don’t hold tack strips under tension.
Choosing Underlay for Tile Floors
Tile is a hard, flat surface. Any underlay will work. The choice depends on how much cushioning you want and whether grout lines are visible.
Rubber underlay is dense. It bridges grout lines. It’s firm underfoot. It costs more. It lasts longer. It’s the best choice if grout line visibility is a concern.
Rebond foam underlay is softer and cheaper. It provides more cushioning. It’s the standard choice for residential carpet. On tile, it works well unless the grout lines are wide or the tile is uneven.
Synthetic underlay (polyurethane-based) offers a middle ground. It’s denser than foam, softer than rubber. It’s moisture-resistant, which matters if you’re carpeting a tile floor in a basement or bathroom.
Thickness depends on personal preference. 7/16-inch underlay is standard. 1/2-inch underlay is plush. Thicker underlay raises the carpet height, which affects transitions at doorways.
For tile in good condition with narrow grout lines, standard rebond foam underlay works fine. For tile with wide grout lines or uneven surfaces, upgrade to rubber or high-density synthetic.
Height Transitions at Doorways and Adjoining Rooms
Carpet and underlay add 1 to 1.5 inches to the floor height. If the adjoining room has tile at the original height, you’ll have a step up at the doorway.
Transition strips solve this. Metal or wood strips bridge the height difference and prevent the carpet edge from fraying. The strip sits in the doorway, screwed or glued to the subfloor.
Reducer strips taper from the higher carpet surface down to the lower tile surface. They create a gentle slope instead of a hard step. Use these for high-traffic doorways where tripping is a concern.
T-molding strips work when both sides are at the same height. If you’re carpeting multiple rooms over tile and the carpet height is consistent, T-molding creates a clean separation between rooms.
For doorways where the height difference is extreme (more than 1.5 inches), consider removing the tile in the doorway area and installing a flush transition. This requires cutting the tile, which is difficult without a tile saw.
Plan transitions before installing carpet. Measure the height difference. Buy the appropriate transition strip type. Install the strip before stretching the carpet—the carpet edge tucks under the strip.
When Tile Condition Prevents Carpet Installation
Loose tiles move under foot traffic. Carpet on top won’t stabilize them. The movement will loosen the tack strips and cause the carpet to ripple.
Remove loose tiles. Apply new thinset mortar. Reset the tiles. Let the mortar cure for 24 hours. Then proceed with carpet installation.
Cracked tiles can puncture underlay or create uneven spots that show through the carpet. Remove and replace cracked tiles, or fill the cracks with tile epoxy if the tile is still structurally sound.
Uneven tile—where some tiles sit higher or lower than their neighbors—will create bumps in the carpet. Grind down high tiles with a tile grinder. Fill low spots with self-leveling compound.
Dirty or greasy tile won’t bond with adhesive. Clean the tile thoroughly before installing tack strips. Use a degreaser if the tile was in a kitchen or near a stove.
If the tile floor has widespread problems—many loose or cracked tiles, large height variations, or extensive damage—removing the tile may be easier than repairing it. Carpet installed over a damaged tile floor will look uneven and won’t last.
Moisture Considerations for Tile Floors
Tile itself is waterproof. The grout is not. Water can seep through grout lines and reach the subfloor beneath. If the subfloor is wood, it can rot. If the subfloor is concrete, it can release moisture vapor.
Before carpeting over tile in a basement, bathroom, or laundry room, check for moisture. Run a plastic sheet test. Tape a 2-by-2-foot plastic sheet to the tile. Wait 24 hours. If condensation forms, moisture is present.
Seal the grout lines before installing carpet if moisture is a concern. Use a grout sealer (available at any hardware store). Apply it with a small brush. Let it dry. This prevents water from seeping through the grout.
If the tile is in a basement and you’re concerned about moisture from the concrete slab beneath, install a vapor barrier over the tile before laying underlay. Use 6-mil polyethylene sheeting. Overlap seams and tape them.
For most above-grade tile floors, moisture is not an issue. Tile in bathrooms or basements requires extra caution. If the tile has been down for years without moisture problems, it’s probably safe to carpet over.
Reversibility: Removing Carpet from Tile Later
Carpet removal from tile is straightforward. Pull up the carpet and underlay. Remove the tack strips. Scrape off adhesive residue with a putty knife. Clean the tile with a degreaser.
If you used adhesive to secure the tack strips, expect some adhesive residue. Goo Gone or a citrus-based adhesive remover will dissolve most construction adhesives. Scrape gently to avoid scratching the tile glaze.
If you used masonry screws, you’ll have holes in the tile. Fill them with tile epoxy or grout. The holes will be visible but small.
The tile underneath will be clean and intact. No sanding or refinishing required. Grout may be discolored where the carpet was if the tile floor is old and the grout has aged unevenly. Re-grout if necessary.
For homeowners who want a temporary flooring change, carpet over tile is one of the least destructive options. The tile remains usable. Removal takes a few hours. No subfloor damage occurs.
FAQ
Can I install carpet over any type of tile? Yes—ceramic, porcelain, and natural stone tile all work. The tile must be firmly adhered to the subfloor. Loose or cracked tiles should be repaired first.
Will I see the grout lines through the carpet? Possibly, especially with thin carpet and underlay. Use dense underlay (rubber or high-density synthetic) and medium to thick pile carpet to minimize visibility.
How do I attach tack strips to tile without drilling? Use concrete adhesive. Clean the tile surface, apply adhesive to the tack strip, press it down, and let it cure for 24 hours. This works for most residential installs.
What happens if the tile is uneven? Uneven tile will create bumps in the carpet. Grind down high tiles or apply self-leveling compound over the entire floor to create a smooth surface before installing carpet.
Can I install carpet over bathroom tile? Yes, but bathrooms have high humidity. Use moisture-resistant underlay and ensure the grout is sealed. Carpet in bathrooms is uncommon due to moisture and hygiene concerns—consider whether a different flooring type is more appropriate.
Do I need a transition strip between carpet and tile? Yes. Carpet and underlay raise the floor height by 1–1.5 inches. A transition strip bridges the height difference and prevents the carpet edge from fraying.
Can I install stair carpet over tiled stairs? Yes. Use adhesive to secure tack strips to the tile. Tiled stairs are hard and cold—carpet adds safety and warmth. Ensure nosing transitions are secure.
Will removing carpet damage the tile? Adhesive residue may remain. It can be removed with adhesive remover. If you used masonry screws, you’ll have small holes in the tile that can be filled with grout or epoxy.
Can I install carpet over tile in a basement? Yes. Tile on a concrete slab can release moisture vapor. Test for moisture first. Use a vapor barrier over the tile if moisture is present. Basement carpet over tile is common in finished basements.
How much does it cost to install carpet over tile in Ottawa? Expect $4–$6 per square foot for carpet, underlay, and installation. Add $100–$200 for transition strips and adhesive. For a detailed quote, visit our contact page.