Grey Stains on Carpet Around Edges of Heat Vents

January 20th 2015
Grey Stains on Carpet Around Edges of Heat Vents



Stains around heat registers and outside walls as well as inside walls and staircases are caused from air infiltration and ex-filtration.


1.  Homes with forced air furnaces will have stains around the heat registers as well as outside walls.  Stains on the carpet on inside walls and stair cases are caused from positive air being pushed out under outside walls, and your carpet becomes a filter picking up all the impurities in the air as it passes under the wall (This shows up more on light coloured carpets).




2.  Some houses with forced air furnaces will have stains on carpet around heat register floor vents caused from air being pushed around the register when the register is closed (keep in mind, a register louver is for directing the airflow not to shut off or turn on).  Also stains found in areas of staircases or stair wells and inside walls, indicate cold return to the furnace is short cutting ways to get to the furnace blower, thus pulling air under the walls and around stair treads to cold air duct running under the floor joist in the basement.




3.  Electric, hot water, radiant or convection heated homes can have similar stains show up, but always on outside walls.  This is caused by air leakage from the home (windows & doors etc.).  Range hood fans, bathroom fans exhausting air out of the home and make up air or infiltration air coming in under the outside walls, thus staining light coloured flooring.



How To Repair:


Outside, Inside Walls and Staircases


Remove carpet from carpet strip, smooth strip and caulk with a draft stop caulking compound between the bottom plate of the wall and the sub-floor (Make sure the area is clean first).


Heat Register Vents


Using duct tape, apply over metal heat register boot, under and onto plywood or shiplap sub floor, terminating under carpet by 1 inch.  NOTE: This should be done on light coloured vinyl floors as well to stop from staining.  Duct tape should terminate on top of vinyl to project out beyond the register vent.



How To Clean:


The residue left behind from air infiltration and exfiltration can be cleaned with a product called Pink Solution.  Pink Solution is available at many retailers in Canada.


Apply Pink Solution directly onto stained area, until soaked.  Knead with your fingertips until black shows in the foam.  Apply again with Pink Solution mix and knead again.  Blot with white towel or absorbing cloth.  Repeat if necessary.  Dry with a hair dryer.  NOTE: Pink Solution can be used on many stains such as wine, asphalt, mold, candle wax, permanent marker, grease, oil, etc.


It’s just that easy!