It can be understandable why a homeowner might want to install carpet over carpet. Your motivations may be:
- Saves on the cost of pulling up and disposing of the old carpet.
- Provides one extra layer of insulation for cold floors.
- Installing a pad is not necessary -- the existing carpet acts as padding.
- Existing carpet is glued down, not tacked -- so removal will be extra-expensive and time-consuming.
- Keeps carpet waste materials out of the landfill.
- Makes it easier to dispose of the old carpet. Rather than cutting into small pieces and including it with your household trash, the old carpet is effectively "disposed of" under your new carpet.
5 Reasons Not to Put Carpet on Carpet
Carpeting industry professionals tell us that putting carpet over carpet is inadvisable for many reasons.
- Tack Strips: By leaving a layer of carpet, you make it that much harder to nail down the tack strips (those long, wooden strips around the perimeter with upward-pointing spikes). Nails on tack strips run about 3/4" long -- far too short to penetrate carpet plus a pad (if the carpet has one) and into the sub-floor.
- Inadequate Base: Carpeting needs an adequate base for installation. Carpet installed with an improper base will wear out quickly. There are many aspects to this, but consider just this one: traffic patterns worn into the existing carpet will be transmitted to the new carpet.
- Harbors Dirt, Mold: Studies show that mold and mildew in carpeting are exacerbated by the presence of dirt. Dirt and moisture, with high temperatures added, equal mold and mildew. It is virtually impossible to clean an old carpet enough to remove all of the dirt. Yet if you go the route of professional carpet-cleaning, you're already spending money that could have been spent on removing the carpet in the first place.
- Additional Floor Layers: By adding an extra layer onto your flooring, effectively "lowering your ceiling." If this is a basement or any other height-challenged room, every inch counts. Don't forget that adding height to your carpet will mean that doors will scrape and trim will have to be repositioned.
- Sub-Floor Quality Check: Ripping up carpet lets you assess the status of your sub-floor. This will provide you with an opportunity for repairing damaged sub-floor. Keep in mind that if a previous owner has installed low-quality carpet, this may signal problems underneath--particularly problems that are difficult to deal with, such as rot or mold.
Carpet on Carpet (or Not) Tips
If you still feel after reviewing your options that installing carpet over existing carpet is the best route, here are some tips for that strategy:
- Go Low: Extremely low-pile carpet is the only kind that would work. The lower, the better.
- Keep It Temporary: At best, carpet-on-carpet is a short-term solution. So, if you are house-flipping or intending to stay in your home for a short while, this option may work.
- Using Failed Glue to Your Advantage: Have you even tried removing that glued-down carpet? Even though glue-down can be notoriously hard to remove, some old carpet adhesives have essentially failed over the years and broken up. Test a corner of the carpet and see how hard it is to pull up -- you might get lucky.
- Carpet Recycle Options: Concerned about dumping carpet in landfills? There is a non-profit consortium called Carpet America Recovery Effort that helps plug homeowners into companies that recycle carpeting.
- Better Scraping Electrically: When you do need to laboriously scrape up glued-down carpet, don't do this by hand; it's simply too difficult. Instead, recruit the services of an electric scraper, like the multi-tool found in the Ridgid 12v Lithium-Ion Drill/Jobmax Combo.
- Carpet + Wood + Carpet: Thin plywood underlayment atop low-pile carpet is better than just putting the new carpet straight on. The underlayment would provide more of a rigid base for the new carpet.