Local Conditions
What Montgomery Air Does to a Rug’s Foundation
Damp is a shoulder-season problem in Montgomery rather than a summer one. 142 days a year sit at or above 75% relative humidity and 93 of those reach 80%, but they are bunched into spring and fall, with 67 days over ninety degrees in between and 15 freezing nights at the far end. Rugs here are damaged by the transitions more than by either extreme.
142
Days a year at or above 75% relative humidity
20
Longest unbroken damp run, in days
15
Nights a year at or below freezing
48.9
Inches of rain a year
Heat is doing most of the work
67 days a year over ninety degrees is at the top of this network, and heat is not a neutral factor for a rug: everything biological in a damp foundation moves faster warm than cool.
Set that against 142 damp days a year and 48.9 inches of rain, and the warm months are the part of the calendar that does the damage.
Clothes moths also complete more generations in a warm house than in a cold one, which is why moth grazing found here tends to be further along than the same infestation found further north — the larvae work the underside first, so the pile looks intact while the knots behind it are going.
Where the house puts the rug
In Hampstead, Halcyon and Arrowhead the rugs are mostly on slab, which behaves nothing like a joisted floor.
A slab is in direct contact with ground moisture and, in older construction, often has no vapor barrier under it; a rug laid straight onto one is being wetted from below continuously rather than seasonally, and the cotton foundation is the part in contact with it.
Old Cloverdale, Arrowhead and Pike Road keep a lot of original wood floors, and an original board floor is a moisture path rather than a barrier.
Old boards shrink, gap and let air through from whatever is below them, so the rug over the top is in exchange with the underfloor space. That is fine for 223 days a year and not fine for the other 142.
The oldest housing on the collection route goes back to the 1810s, and construction of that age was not built to keep ground moisture out of the rooms above it — which is worth remembering before blaming a rug's condition on the rug.
What that actually sends in for repair
Foundation loss, not surface wear
Cellulose held damp loses strength, and 20 unbroken days above 75% is long enough for it to matter.
A foundation going that way gives no cosmetic warning, so the test is mechanical: fold a corner and see whether it flexes or crackles, and pull gently on a fringe tassel to see whether it is still anchored in anything.
Backings and sizing letting go
Hand-tufted rugs are held together by adhesive and a cloth backing rather than by knots, and 67 days a year over ninety degrees combined with 142 damp days is hard on that construction.
It fails as a fine grit that comes out of the back, a backing that lifts away from the body of the rug, and a smell that returns after cleaning because the source is the adhesive layer rather than the pile.
Dyes that moved before we saw the rug
93 days a year reach 80% relative humidity, where a wet rug stays wet, and an unstable dye that is kept wet and warm will travel.
Most of what looks like a stain on an old rug is dye that migrated during an earlier soaking, and it is corrected by hand where the fiber is still sound rather than by washing harder.
Figures above are from the ERA5 reanalysis record for the five years from 2021 through 2025,
taken at the center of the the River Region service area. If what you are seeing on your rug
matches any of this, send photographs and we will tell you which of these it is.