Tired of how the carpet in your car looks? Maybe it’s time to change it out. Stains and spills are unsightly, and will also start to smell if not cleaned on time. But this is just the touching surface of things. More serious are rust pockets in the carpet that are starting to form clumps, and torn or frayed carpeting with mats on top slipping. Ultimately, you’ll also want to check the condition of the underlay, as this is where a lot of problems begin.
Why a Good Carpet is More Than Just Good Looks?
Having luxurious and plush carpeting enhances the feel of any car interior. You’ll want fabrics soft to the touch and in colours that go well with the rest of the vehicle. Keeping up appearances is important, but there’s more substance to the carpet and underlay than what’s evident at first sight.
First, carpeting serves as an insulator. It keeps the cabin cool in summer and warm in winter. The combination of carpet and underlay serves to reduce heat from the engine and transmission parts and keeps road, tyre and engine noise to a minimum. Variants with UV resistance (and this is most carpets) also won’t fade in the piercing Aussie sun. Carmakers pour a lot of work into slashing noise, vibration and harshness (NVH) levels by using the best carpeting products. The aim is to get the cabin as cool and quiet as possible so drivers and passengers can enjoy a comfy ride. Thicker combos of multiple layers of underlay and moulded carpet produce the best results.
Then there’s waterproofing. This works in both directions and is handled with specially-formulated waterproof car carpet underlay to contain any liquids. The material doesn’t soak up water or spills like traditional cotton shoddy, and is a great replacement for stock carpet underlay that came with your vehicle. You’ll avoid the risk of rust eating into the car floor, or water and humidity playing havoc with wiring and electrical connections. Being rot-free, the underlay will also retain form throughout the lifetime of the vehicle and better conform to the carpet that’s laid on top.
Replacing an Old Carpet and Carpet Underlay
You might be tempted to replace only the carpet and keep the old underlay, but cost-cutting here isn’t effective. Older cars and those that most of us like to rebuild have cotton shoddy or jute between the floor and carpet, and this is prone to rotting and clumping. In addition, it soaks up liquids. For convertibles, roadsters, 4WDs and work vehicles where road spray, water and spills are a daily occurrence, you’ll want something more durable and reliable.
To get the best sound deadening, thermal insulation and waterproofing, carpet underlay is done in two stages. The first is achieved with a thinner layer of butyl rubber with an aluminium top layer. This is what prevents heat, vibrations, and liquids from spreading through the car floor and into the cabin. It is easily cut, shaped and sticks to the car floor and adheres to the surfaces with no issues with uneven contours. On top of this is the second piece of underlay and here there are several options.
Mass Vinyl is what’s used in newer performance and luxury cars to drone out engine, exhaust and transmission sounds, as well as the high temperatures they generate. This requires glue and joiner tape when being put in. Another option is what is known as an acoustic liner –a multi-layered carpet underlay, with an open and closed-cell foam structure, and a peel and stick adhesive for easy installation. Both are used where there’s more space, with thicknesses ranging between 12-14mm.
If space is an issue, then go for waterproof car carpet underlay. This has all the benefits of both mass vinyl and acoustic liners, and adds a few more. It rounds out as a thinner option, at 10mm (so can take carpet in different thicknesses and designs), is self-adhesive and easier and quicker to install and has high-temperature resistance, making it flame retardant in the event of a fire. It will also reduce radiant heat from hot engine parts (especially around the firewall) and this can prove the difference between a pleasurable or uncomfortable ride.
The selling point though is that it best handles liquids. Consisting of a single-layer closed-cell foam, waterproof underlay won’t stay damp, doesn’t rot over time, or attract mould. And it won’t exacerbate the nasty smells that you get with traditional cotton liners. Besides the flooring, it can also be used in firewalls, roof skins, inside cavities, round the doors and wheel arches.
Installation is simple. The foam is lightweight and easy to handle, the protective packaging easily peeled off and the underlay sticks and holds to any surface. Cut the underlay to fit the shape of the floor, with incisions for the gear stick, handbrake and other inclusions. Next is your choice of carpet. For all areas not directly under foot, go with stretch carpet, preferably in a plusher, cut pile design with a smooth texture and in a suitable colour. To get the best of your installed underlay, choose a pre-cut moulded carpet for your make and model. This too is a cut-pile design (or loop-pile when rebuilding classics), can be had in different colours and colour combos, and with everything sized and shaped for your vehicle will need almost no time to get right. Once you’ve completed replacing old and worn carpet and underlay, get a set of inexpensive car mats to round out the picture.