N
The Daily Horizon

Can you put two gaskets together?

Author

Isabella Harris

Updated on January 13, 2026

A gasket is there to provide a seal between two surfaces. Using two gaskets creates another two surfaces that have to seal, and equally could fail.

Is it OK to double gasket?

We do not recommend stacking numerous gaskets in the same flange. In-house tests have shown that a better way to fill a 1/2" gap, for example, is to install a 1/16" gasket on each side of a 3/8" thick incompressible spacer ring.

Can I put 2 head gaskets together?

it is better to use one. two won't harm anything but sometimes having two will cause one gasket to squeeze outward and create a leak. also, two will raise the head slightly causing slight compression drop.

Does it matter which way a gasket goes?

Some gaskets are asymmetric, and the correct orientation can be visually distinguished. However, others can be installed with either side facing up and the gasket will seal either way. Sometimes gaskets for the same engine might appear very similar, but will not function properly if installed in the wrong direction.

How many exhaust gaskets do I need?

In many car engine system's, only a single exhaust manifold gasket is needed. However, some engines, like a V6 or V8 will require two. The materials used for other gaskets within the car's engine system, such as flange gaskets and ring gaskets, are usually matched to the exhaust manifold gasket too.

Ask Paul: Doubling Header Gaskets

Can you use 2 exhaust gaskets?

A gasket is there to provide a seal between two surfaces. Using two gaskets creates another two surfaces that have to seal, and equally could fail.

Does a muffler need a gasket?

Yes you should put in new gaskets for your exhaust system. If you do not replace the gaskets there is the potential that the old gasket will leak and cause exhaust noise. When replacing anything that has a gasket it is always good practice to the replace the gaskets.

Do rubber gaskets need sealant?

Most rubber gaskets are used to seal a piece of machinery or aid in the sealing process. While most gaskets don't require gasket sealant, it is still a common tool used to allow for a better placement when fitting onto the application.

Are head gaskets the same on both sides?

Some gaskets are nearly identical on both sides, but often there is a slight alignment issue either for the bolt holes or ports. Be sure to have the proper side so it assembles properly.

Can I use RTV instead of a gasket?

Due to their shape and design, some molded rubber gaskets necessitate the use of RTV as a supplemental sealer. Please note that RTV is not to be used on the entire gasket; the gasket should be installed clean and dry. RTV should only be used on the corners of the gasket and/or stepped casting areas that have a gap.

Do paper gaskets need sealant?

Gasket applications, such as when dealing with oils or differential covers, will require a sealant for added protection. This enhances the sealing ability and ensures no leaks are present.

Why are gaskets needed?

A gasket stores energy, like a spring, and seals two mating surfaces that fail to perfectly meet. Wikipedia: “Fills the space between two objects, generally to prevent leakage between the two objects while under compression.

Do rubber valve cover gaskets need sealant?

Although valve cover gaskets don't necessarily need sealers or cements, it's a common practice to glue the gasket to the valve cover. There are a number of sealant choices, too. For this application, Permatex No. 1, RTVs or Permatex High Tack gasket sealant work well.

Do you put silicone on both sides of a gasket?

NEVER use silicone on both sides of the gasket, the gasket will slip and slide all over the place instead of staying put and clamping down. Another substitute for the high tack is Copper Coat (in the copper spray can). This works really well for head gaskets since it's a light film.

Can you use gasket sealer instead of a gasket?

While today's gasket makers and flange sealants can replace most conventional, formed, or multi-material gaskets, they should never be used to replace a head gasket.

Can a car run without an exhaust?

It's not safe to drive without an exhaust pipe. Instead of harmful engine gasses being released behind your car, they'll be exiting at the bottom of your vehicle. This can cause dangerous amounts of carbon monoxide to leak into your cabin.

Are exhaust gaskets important?

Without the gasket, the exhaust system functions more like a leaf-blower, blasting at a general area and hoping most of the clutter will blow away. If you do not have an efficient exhaust system from your engine, your engine power and performance will be affected negatively.

Do you put grease on gaskets?

I use grease. Makes them slightly 'softer' to bed down and easier to dis-assemble years later. It also keeps them in place while fitting the mating piece. This is the correct and time honoured way to assemble with paper gaskets and head gaskets.

Where do you put gasket sealer?

Unless a primer is required, you should apply the sealant to the prepared surface. Apply an even coat to all sides of the gasket. Where there are broad surfaces, apply in a thin ribbon of 6mm or less in diameter around the surface edges. Allow the sealant to air-dry until it becomes tacky when touched.