![]() ![]() Monitor through several weeks of rainfall to be safe.Ī water-resistive vapor barrier should be applied both inside and outside, and if you have space, insulate the exterior before the final finishes are applied.ĭrywall isn’t a cure for poor framing or joist imperfections. Wait for rain to make sure water isn’t entering through any exterior walls. If the mortar is too hard it will crack when the masonry shifts, so ensure the mortar is appropriate for the masonry. Prior to sheetrock installation, check the wall for dampness and have the contractor hose it down with water from above or outside to test whether there are gaps. There should be no open seams on exterior masonry or in transitional areas such as where the wall meets the roof.Ĭoncrete is porous and should be treated with a water repellent on the outside and a vapor barrier on both sides.įoundations should be waterproofed (and insulated in cold climates), as otherwise the water can both enter or go up the wall through capillary action. I read an article recently in the C onstruction SpecifierĮxamples of water infiltration from the site Construction Specifier It’s also not as uncommon as one might expect. In retrospect, filling masonry seams and waterproofing may seem like common sense and obvious…but it is shocking how often these practices are not followed. Luckily, we discovered the issues before the tile and finishes were installed, otherwise the tile would have fallen off which would have been expensive and dangerous. The bathroom must have had moisture issues prior to the the board installation, but the contractor either did not notice or care. Water plus drywall is a mushy disaster waiting to happen. Water can also dislodge the tape used to cover drywall seams or soften the panels at the screws. Paper facings and additives also react to water and can get moldy. Gypsum turns into a paste when it gets wet, and drywall will crumple. The materials used to make drywall, such as gypsum, paper, and organic additives and binders, all react with water in such a way that their chemical composition is altered. If it is exposed for a longer period of time, it will need to be replaced. If drywall is exposed to water for a short period of time (usually less than 48 hours), it may be possible to dry it out. Drywall installation is straightforward, but as usual, my project went sideways.Ĭoncrete blocks being filled. A 1/2" sheet of drywall can weigh almost 60 pounds but the newer lightweight drywall is about 20 pounds lighter. Plywood weighs roughly 2 pounds per square foot, while drywall weighs 2.75 pounds per square foot. The plaster core in the drywall is what makes it heavy. ![]() The assembled unit is then heated to temperatures up to 500 degrees Fahrenheit, which dries the material out and prepares it for cutting. The paste is spread onto paper, and then another sheet of paper is laid on top. The core of drywall is composed of ground gypsum crystal (calcium sulfate dihydrate), fiber, a foaming agent, additives (like starch, paper pulp, etc.), and an emulsifier or thickener, which are all blended with water to form a thick paste. When gypsum is crushed and heated to remove 75% of its water content, it is known as Plaster of Paris or calcined gypsum. Gypsum is a naturally occurring sulfite mineral found in gray, white, or pink sedimentary rock. ![]() Drywall consists of a core of wet gypsum plaster pressed between two thick sheets of paper or fiberglass mats. ![]()
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