Can You Patch the Sidewall of a Tire?

Your tires might not be the most complex part of your vehicle, but they’re arguably among the most indispensable. Keeping your tires in good condition is integral to both safety and performance, so when they suffer damage, it’s important to take care of it immediately. You’re likely familiar with patching tires, but are there limits to this practice? For instance, can you patch the sidewall of a tire?

Where the Rubber Meets the Road

Tires have more going on than meets the eye. Over the years, tire technology has evolved to make them stronger, longer-lasting and safer in various driving conditions. There are many parts of a tire, but the two main external parts are the tread and the sidewall.

The tread is what contacts the road. It’s very thick, it wears down over time, and it’s the part you pay special attention to when you’re watching out for alignment issues. It is meant to wear down, but evenly.

The sidewall is thinner because it is not designed to contact the road and wear down. It protects the inner plies of the tire, which are structural, and it flexes as the tire rotates and bears the weight of the vehicle.

Patching Your Tires

Many people keep tire plug kits in their vehicles for emergency roadside repairs, but patches are a little more in-depth. In order to properly install a patch, the tire must be safely removed from the vehicle and the rim. The hole or tear area must be cleaned up and covered with vulcanized cement so that the patch can be installed from the inside and sealed before the tire is reinstalled on the vehicle.

The patch adheres to the tire’s material around the damage, and the added pressure of inflation actually works to press the patch outward further plugging the hole. If done correctly, this creates a seal that can last the rest of the tire’s life. Patches are viable for repairing small holes or tears, generally, those that are 1/4 inch or less.

Fixing Damage in the Sidewall

If you have a leak, hole or tear in your sidewall as opposed to your tread, you should not repair it with a patch. The thinness of the sidewall gives little material for a patch to adhere to, and the damage to the sidewall leaves the tire structurally compromised. As mentioned before, the sidewall tends to flex, putting extra stress on the repair and increasing the likelihood of patch failure, which is more likely to occur at higher speeds and pressures.

Patching the sidewall is simply not a good idea, as a leak or blowout while the vehicle is underway could result in loss of control with catastrophic consequences. So if you end up with a damaged tread, you can plug and patch away, but if the damage is to your sidewall, you’re going to have to replace the tire, which usually means replacing the fronts or rears in pairs.

So can you patch the sidewall of a tire? The answer is a solid no. Luckily, sidewall damage is far less common than damage to the tread, and you can minimize it by paying attention to road conditions, not overloading your vehicle, staying away from the curb when you’re parallel parking, and keeping your tires properly inflated, rotated and maintained.

Check out all the tires, wheels and accessories available on NAPA Online, or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on patching tires, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photos courtesy of Blair Lampe.