Home › Sullivan's Island
Mold Testing on Sullivan's Island, SC
The front beach on Sullivan's Island has been building seaward for decades. The vegetation followed it out. Maritime forest and shrub thicket grew in over that new ground, so houses placed to catch full sun and a sea breeze now stand in shade for much of the day.
That changes the moisture problem completely. Nothing floods. Nothing dramatic happens at all. Roofs, north walls and porch skirting simply never dry all the way between rains. A surface that stays slightly damp week after week grows something slowly.
The housing spans the whole range. Old beach cottages near the Station numbers off Middle Street sit on brick piers with deep porches, close to Fort Moultrie and the mouth of Charleston harbor. Newer construction stands elevated to current flood requirements. Both types end up with the same shaded, salt-damp exterior once the thicket is up around them.
Where we come in: we are not the people with the pump and the cassette. We introduce owners here to independent samplers. What they find belongs to you, the lab report included, whether or not you ever hire anybody to act on it.
Why do the shaded walls behind the thicket never dry out?
Sun and moving air are what dry a wall. The maritime forest that grew in on the accreted land takes both away. A north elevation under live oak and wax myrtle can stay damp from one rain to the next through a whole season. Salt on the siding makes that worse by pulling moisture out of the air long after the rain stopped. What grows there is usually surface growth on paint, trim and porch lattice rather than anything structural, at least at first.
Inside, the same shaded walls run cooler than the rest of the house, so closets and corners on the north side collect condensation in summer. Owners near Middle Street tend to notice a smell in a linen closet or stiffness in clothes hung on an outside wall long before they see a mark anywhere.
The back of the island behaves differently from the front. Facing the waterway and the marsh toward Mount Pleasant, those elevations get less sun and more still air than the ocean side, where wind off the beach at least moves things along. Between Fort Moultrie and Breach Inlet the shade is uneven street by street, which is why one house has a green north wall and its neighbor does not.
Does growth on the siding say anything about the air indoors?
Not by itself. Growth on a shaded island wall is telling you about the outside of that wall and the shade over it, nothing more. Plenty of houses along the Station numbers carry a green cast on the north siding with perfectly ordinary indoor air. The connection becomes real only where the wet siding meets a place water can get in: an old porch roof junction, a window sill on a pier cottage, a spot where skirting holds moisture against framing.
Sampling sorts that out cheaply. A trap in the room you are worried about and a trap outside, run the same afternoon, tell you whether the indoor spore load looks like the island air or like something living behind the plaster. Houses this close to the harbor mouth give a heavy outdoor catch in summer, which is exactly why a single indoor number gets read wrong by almost everybody.
Under an older pier cottage the check is quick and worth doing first. Skirting and lattice that stay wet keep the air under the floor still. The sills sitting on those piers are the oldest wood in the building. If a sampler finds them dry, the shaded siding outside is a maintenance job rather than a warning.
Paired Air Sampling in Charleston