My Home Was Remediated For Mold, How Do I Rebuild It To Avoid Further Mold Sensitization?
If you have been in the cleaning and restoration business for a substantial length of time you have had customers who have not only been traumatized by their loss but also sensitized by one or more contaminants in the building they occupy. It has happened with office workers after a fire, store employees after duct cleaning with chemicals, children in school following carpet cleaning utilizing standard detergents, and multitudes of residents after fungal contamination has impacted their homes or apartments. Although these cases seem odd, they happen with enough frequency for restoration and cleaning contractors to realize that they are all not psychosomatic in nature.
Occupant sensitization is now recognized as a significant problem by both government agencies and the private sector. A few months ago an architectural firm in New York released a study that concluded with a list of 374 known asthmagens, identified by government agencies, third-party regulatory agencies, and academic sources. The report used the term “asthmagen” instead of “allergen” to emphasize a growing recognition that even contaminants that do not typically evoke an allergic response can be an asthma trigger. In essence, scientists and doctors now realize that sensitization can occur in situations where it was never anticipated in the past. While these particulars about allergens, asthmagens, and sensitization may seem inconsequential, they actually have a direct bearing on cleaning and restoration contractors. There is an evolving trend for restoration professionals to be responsible not only for removing contamination, but also for conducting complete structure cleaning, and even completing the repair/rebuild to minimize future problems.
Over the years, the team at Wonder Makers Environmental has dealt with every one of the specific examples listed at the beginning of this article. Through an extensive process of research, coupled with a good dose of trial and error, we have learned about numerous products and processes that can help in the rebuilding of remediated structures. Therefore, the following recommendations are offered to restoration contractors, builders, and occupants trying to build a safe haven for sensitized individuals. Please note that Wonder Makers has no financial ties to any of the products or processes listed and that there may be other alternatives. Nor are we licensed builders or contractors, so it should be verified that all suggestions meet local building codes. Finally, we would like to hear about any additional techniques that have been successful so that the whole industry can continue to move forward in this critical area.
Suggested Construction Techniques for Building/Restoration for Sensitized Individuals
Foundations
- Slab on grade instead of basement, especially in water-prone areas
- Grade subsoil and landscaping away from house
- 2’ to 4’ buffer zone with rock or stone rather than grass or plants around the structure
- French drain around perimeter of the footings to channel subterranean water away from the basement/slab
- Pea stone or other rock on top of the compacted soil under the cement slab
- Plastic vapor barrier under the cement slab, which is tied to the vapor barriers on the walls
Framing
- Metal framing rather than wood
- Plywood rather than OSB or particleboard for floors, roof deck, and sheathing
- If wood framing is used check lumber for mold and clean/treat prior to installation
- As an alternative to treating individual pieces of the lumber and sheathing, apply an antimicrobial protective coating to the entire structure after it is framed and roofed, but prior to installation of any finish materials
- Consider plywood with a factory-adhered foil radiant barrier for roof deck and sub-floors over a basement or crawl space
- Utilize 45-pound roofing felt or specialty underlayment below shingles
- Install asphalt saturated kraft building paper (ASK) as a vapor barrier on the exterior sheathing rather than house wrap
Attic
- Adequate soffit vents
- Gable vent fan with controls that have both hygrometer and temperature control setting
HVAC components
- Galvanized metal ductwork, seams sealed with aluminized tape, ASTM rated exterior insulation on all supply and return ductwork
- No flexduct
- Pleated supply filter with MERV 13 rating
- Antimicrobial drain pan, coating, venture tape ASTM rated
- Bath exhaust fans on timer delay and tied into the light switch
- PVC pipe rather than flexduct for dryer exhaust
- Fresh air vent of PVC piping to high-efficiency furnace/dryer
Interior walls
- Plaster, if possible, or mold-resistant gypsum board (fiberglass on the back side rather than paper)
- No greenboard in water-prone areas, utilize cement board up to 4’ in all bathrooms kitchens, and mudrooms, as well as all walls and ceilings for shower/tub surrounds
- No MDF particleboard used for walls or cabinets
Cabinets and cupboards
- No particleboard, all plywood construction (APC)
- ¼” bumpers on base to allow drying in the event of leak; gap covered with base trim
Flooring
- Hard flooring with accent area rugs rather than wall-to-wall carpeting
- Maximum size of 6’x8’ for rugs so that they can be rolled up and washed in commercial washing machine
Plumbing
- All flexible connections to sinks, toilets, dishwasher, and clothes washer of braided steel
- Floor drain in laundry room and mechanical room where the water heater is located
- Water heater mounted in secondary collection pan with a connection to floor drain or to out-of-doors
Garage
- Slope concrete from rear of structure to the door
- If a trough is installed in the concrete to catch the bottom of the garage door as a weather seal, ensure that there is a slight slope to the trough so that water has an exit channel out of the garage
Re-Building a Refuge for #Sensitized Individuals @moldsensitized http://t.co/rf3QavVkGe #mold PLS RT
— Mold Sensitized (@moldsensitized) March 30, 2015