Mold removal in Brenham, Texas

Brenham sits about forty minutes south-east of College Station, in Washington County. The town has a well-preserved historic centre, a great deal of nineteenth and early twentieth century housing, and a surrounding countryside of rolling pasture and small acreages.

The work here is different in kind, not just in location.

Working on genuinely old houses

A house from the 1890s or 1910s is not a modern house with more character. The assemblies are different and so are the failure modes.

Lime plaster on wood lath. Where the original plaster survives, it is worth understanding before it gets demolished. Plaster is far more moisture-tolerant than gypsum board and can often be dried and kept where drywall would be removed. It also cannot be replaced like for like by most contractors, so removing it is a permanent decision made in an afternoon.

No cavity, or an uninsulated one. Many of these walls were built with no insulation at all. Adding it later without a vapour strategy — blown into a wall that was designed to dry in both directions — is a common cause of the growth we are called to.

Shiplap and board sheathing rather than plywood or OSB. It behaves better when wet and it dries more readily, provided air can reach it.

Pier and beam throughout. Crawl spaces under old houses in this area are frequently low, uneven and unlined. See crawl space mold removal.

Layers of later work. Sixty years of additions, closed-in porches, and re-roofing. Water frequently gets in at the junction between old and new construction, where two different assemblies meet and nobody detailed the transition.

The rule we apply on historic property

Remove less, dry more, and take longer.

Modern remediation practice leans toward removing porous material because it is fast and cheap to replace. On a house where the material is irreplaceable, that calculation changes. Plaster, old-growth heart pine flooring, original millwork and shiplap are all worth the extra days of controlled drying rather than the extra hour of demolition.

That requires patience and it requires monitoring, which is why we take moisture readings on old houses more often and over more days than on a modern one.

Terrain and water

Washington County is rolling rather than flat, and that shapes where water goes.

Houses cut into a slope have soil against a wall on the uphill side, and that is where we find rising damp and growth at the base of the wall. Where a later addition sits below the level of the original house, it collects whatever the slope delivers.

Downspouts discharging at the foundation on the uphill side are the most common single fault, and extending them is the cheapest correction available.

Heavy rain here also runs fast off pasture and pavement, so property at the bottom of a slope or near a drainage line takes sheet flow rather than a slow rise. See storm and flood cleanup.

Country property

A lot of what we do in Washington County is outside town: small acreages, weekend places, barns converted to living space, and older farmhouses.

Wells and septic. Almost universal outside the city. Septic failures after a wet season produce the same Category 3 cleanup as a municipal backup, and the drain field is usually the limiting factor. See sewage cleanup.

Intermittent occupancy. Weekend and seasonal properties that sit closed with the air conditioning off. In this climate that grows mold on furniture, in closets and on exterior walls with no leak involved at all. Leaving the system running at a modest setting, or fitting a humidistat-controlled dehumidifier, prevents essentially all of it.

Metal buildings and converted structures. Uninsulated metal roofs condense heavily on humid mornings, and the drip lands on whatever is below. Where a barn or workshop has been converted without addressing that, the growth is on the underside of the roof and on stored contents.

Antique shops, bed and breakfasts, and commercial fabric

Brenham's historic downtown carries a particular kind of commercial risk. Retail in nineteenth century masonry buildings, guest accommodation in converted houses, and businesses whose stock is itself vulnerable to humidity.

Two things recur. Masonry walls with no cavity conduct moisture from the exterior straight through to interior finishes, and where a later stud wall and drywall was built against that masonry with no gap, the back of the drywall is permanently damp. Growth there is invisible until the wall is opened.

And flat or low-slope roofs on commercial buildings pond after heavy rain, particularly where a parapet drain is blocked with debris. The interior evidence appears across a wide area of ceiling rather than at one point, which makes the entry hard to locate from below.

For businesses, the scheduling matters as much as the work — see commercial mold remediation. For guest accommodation, an unexplained musty smell in one room is worth investigating early, because it reaches reviews faster than it reaches a maintenance list.

Selling an older property

Historic houses attract buyers who inspect thoroughly, and Texas requires sellers to disclose known mold damage.

A documented remediation with a clearance report and, where the work was licensed, the Texas Certificate of Mold Damage Remediation, is far better in that negotiation than an undocumented cleanup. On a property where the appeal is the original fabric, evidence that the fabric was preserved rather than ripped out matters too.

See mold inspection for pre-sale assessment.