Grout Sealers

Sealing grouts will make grout joints easier to clean and more resistant to water penetration and staining. When water penetrates grout joints, it makes them susceptible to mold and bacterial growth. Even grouts containing mil — dewcides can eventually become moldy. Be­sides sealing grouts in wet areas, the key to mold-free grout is maintenance. Bathrooms should be kept dry by using exhaust fans, and grout joints should be cleaned regularly We do not recommend the commercially avail­able grouts enhanced with additives. We have found the following sealing methods to be generally well-tolerated by chemically sensi­tive individuals:

• AFM Safecoat Grout Sealer: A clear, moisture-resistant sealer for porous tile grout to help prevent staining

• AFM Safecoat Safe Seal: An odorless, zero-VOC, water-based, low-gloss sealer for highly porous surfaces, it can be di­luted in a 50:50 ratio with water and then mixed into the dry grout to form an inte­gral grout sealer

Stone

While stone is generally a healthful and beau­tiful choice for flooring and decorative ac­cents, it raises the same concerns about proper installation as ceramic tile does. The specifica­tions we have outlined for ceramic tile also ap­ply to stone.

We have tested several stone products for radiation and radon content and found a range of readings from very low to high levels. Al­though uranium content in construction ma­terials is not usually considered to be a serious concern, Johns experience, as shared in Case Study 9.2, leads us to conclude that stone can contribute significantly to ambient radon lev­els in a home. We recommend that stone, es­pecially granite, be screened for radon prior to installation, even though the Granite Institute has issued a scientific report concluding that granite countertops do not emit radioactivity into the home. Tests are easily performed as described in Division 13.

Stone Installation

Refer to our discussion of the thickset method in the section on tile installation above and to the section on stone countertops in Divi­sion 6.

Sealers for Stone

Tire following finishes are free of petroleum — based solvents and can be used for most stone flooring, shelving, and countertops:

• AFM Safecoat MexeSeal: A durable sealer providing water and oil repellency, applied over AFM Safecoat Paver Seal.003, an un­dersealer for porous materials

• Lithofin: Stone sealers

• Livos Meldos Hard Oil and Livos Bilo Floor Wax: A penetrating oil sealer and a clear, mar-resistant finish wax respec­tively; can be odorous when first applied and should be carefully tested prior to use by a chemically sensitive individual

• Naturel Cleaner and Sealer: Water — soluble flakes that clean, protect, and fin­ish stone surfaces

Flooring

Flooring Installation Over Concrete

Flooring materials such as wood, carpeting, and resilient flooring are often laid over a con­crete slab. If the concrete slab has a high mois­ture content resulting from inadequate cur­ing time or from a high water table, then the perfect conditions exist for mold growth: an environment that is dark, moist, still, and nu­tritious. Flooring manufacturers publish rec­ommended maximum vapor-emissions levels for installations of their products over con­crete slab. When these levels are exceeded, the warranty is void. Unfortunately, slabs are rarely measured for vapor emissions.

Where finished flooring, especially wood flooring, is laid over concrete slab with radi­ant heat tubing in it, we have encountered an additional problem. A slab that appears to be fully cured will have unacceptably high vapor emissions when the heat is first turned on. Often the heat is turned on only after floor fin­ishes have been applied and the construction is completed.

We consider these to be important quality control issues and suggest the following speci­fications: [16] [17]

CASE STUDY 9.2

Updated: 19 ноября, 2015 — 6:16 пп