Should You Put A Rug Over A Floor Register? (Yes…. And No?)

Floor registers have one job – to allow ample circulation of cold and hot air throughout your space.

If you live in an older home, you are probably being serviced with a gravity-based heating system, which takes advantage of your home’s centralized furnace.

The heat should slowly move through your home uninterrupted and rise through the vents installed on the floor.

Covering the grates and registers on your floor can be both hazardous and harmless depending on the thickness and material of construction of your carpet.

A thick rug would block the registers and prevent the cold or hot air from reaching your space. This can negatively affect the way your heating and cooling systems serve your home.

Likewise, installing an average or thin breathable rug on the registers may still have an impact on how the cooling and heating systems serve your home but not as adversely as their thick counterparts do.

ONE Benefit of Blocked Registers

It actually can be beneficial to cover floor registers with a carpet.

If you have small children or pets in your household, for example, it only makes sense to cover the registers to prevent accidents.

Crawling children as well as those learning to walk may attempt to remove the floor registers and even try to reach their hands inside.

This can depend on the size – registers in the standard range of 2-1/4″ X 10″ and 8″ X 14″ (4″ X 10″, 4″ X 12″, 6″ X 10″, and 6″ X 12″ in medium-size rooms such as dining rooms and bedrooms) are small enough to trap the arm of a child.

Such areas as the hallways, bathrooms, and laundry areas require even smaller registers which can trap the legs of a small dog.

Older grates tend to be larger and worse off.

Households with such curious folks, therefore, should have rugs installed over registers in a way that permits flawless circulation of air without posing hazards.

Why to Never Place A Rug Over Floor Vents – 5 Potential risks

1. High energy bills

If your home is cooled or heated by a heating/cooling system, covering your registers would be potentially dangerous.

As the system attempts to push the cold/hot air through the registers, the blocked vents offer resistance to this flow because of the overlying carpet.

At some point, the system will need to push the air harder against the blockage. The result is normally bloated energy bills.

And, what is the point in leaving your cooling or heating system running with blocked registers?

It could simply mean you are pumping out hot/cold air that you don’t utilize, thus a bloated energy bill for services you didn’t even use.

2. Asbestos contamination

The risk can be higher if your walls contain some asbestos insulation. In the long run, the blocked air may start to loosen parts of the insulation in the floor and walls.

The longer the register stays blocked, the more the asbestos fibers accumulate under it.

When you lift the rug next time and remove the register, the particles will be released in the air and render your home unlivable.

Because modern construction standards don’t permit the use of asbestos, you are more likely to find asbestos insulation in older homes than modern ones.

3. Destruction Of the Rig

The fabrics used to make rugs are vulnerable to damp and musty conditions, especially when exposed for long periods.

The air emanating from the vents is supposed to cool your home, therefore, it is cold enough to form a moist layer under the carpet.

If it ends up with the formation of mildew or mold, some ugly marks and discolorations may be left underneath, meaning you don’t stand a chance of ever reselling it.

If this goes on unchecked, some parts of your rug may beyond damaged repair. You may never be able to use it again or resale.

4. Fire And Freeze Hazard

The effects of blocked vents may spread to another device you probably didn’t think about – the furnace.

Your furnace is equipped with a heat exchanger – a metal coil that receives the air, heats it, and passes it to the rest of the system to be streamed into the room – that must be fed with air by the systems’ blowers.

Blocked vents would mean less air is reaching the heat exchanger. In extreme situations, the heat exchanger may overheat, expand, and crack.

The end product is usually a chilly home, a fire hazard, bloated energy bills, and a very unhappy homeowner.

5. Risk of mold growth

The rug will trap the cold and humid air emanating from the registers under it.

When the stagnant moist air meets cotton, linen, or some synthetic and natural fibers, a musty environment is created underneath.

Mildew and mold thrive well in such an environment.

You may never realize until it’s too late because all the growth takes place under your rug away from your sight.

And because floor rugs are sometimes hygroscopic (they are prone to soaking up moisture very much like a sponge), they will be slowly lowered to landfill status in the long run.

Typical Sizes Of Floor Area Rugs

Floor registers are strategically installed close to the edge of the floor and walls.

Unless it is very necessary, installing registers close to the center of the floor borders to malpractice of the contractor’s side.

Yet their size and how they are installed relative to other flooring infrastructure may affect how other things in your household works.

The typical size of an average area rug found in most homes in America is 5″ X 8,” 6″ X 9,” and 7″ X 10.” Large rooms would require rugs as large as 8″ X 10,” 10″ X 12,” 10″ X 14,” or 12″ X 15.” 

Note that these are seldom wall to wall measurements – in most cases, some space would be left between the edges of the rug and the junction of the floor and the wall.

It is this space that holds most of the floor registers.

However, because of the individual tastes and the fact that sizes of the floor can vary a bit, the rug may end up extending to the end of the floor, covering the critical cooling/heating registers.


Covering the floor registers with a rug can be advantageous and disadvantageous at the same time.

If you have small pets or small children, it would be a good idea to cover the registers to prevent them from getting trapped in the space.

However, the drawbacks far outweigh the benefits.

For instance, covering the registers causes your heating and cooling systems to work harder against the blockage to keep your room ventilated – this can take a toll on your energy consumption.

The fact that the registers are blocked alone means you are not receiving the service they are intended for, which means you are wasting your energy.

If the home heating system is designed to work in tandem with your blocked registers, it may experience overheating because of the failure of the outlet registers to dissipate a load of hot air into the environment.

If it doesn’t result in accidents it may mean you are conducting costly repair and maintenance work more frequently. You can cut parts of your rug off to accommodate the vents when necessary.