Air Duct Mold Removal in La Mesa, CA

Air duct mold removal in La Mesa

La Mesa sits on a plateau, but the marine layer still reaches it. Mornings run damp. Attics run hot by afternoon. That swing is the whole problem. Bare galvanized supply trunks in prewar and 1950s-60s houses sweat when humid air meets cooled metal. Dust settles on the damp surface. Mold grows on the dust, not on the steel.

So the first task is finding the water. Usual suspects: a torn flex inner liner with wet fiberglass behind it, or a rusted drain pan under the coil. A crawlspace return in a raised-foundation home can draw musty soil air too. Salt corrosion works on pans closer to the coast. Fix the moisture source or the growth returns within a season.

Not every black mark is mold. Gray streaking around register boots is usually filter bypass. Postwar ranches here often have one undersized return, so loaded dust goes around the filter and prints on the ceiling. A lab sample settles the question. Guessing wastes everyone's time.

Porous material does not get cleaned. Shedding fiberglass duct liner and colonized flex come out and get replaced. Fogging biocide over a dust layer is cosmetic. It changes the color and leaves the food behind. How much replacement a system needs drives the job more than the number of registers does.