|
|
||
|
|
|
||
|
stucco
Hard Stucco Facts to further demand plastering for your next project. Traditional Hard Stucco cement plaster (stucco) is a time-tested exterior finish. It consists of Portland cement-based materials and sand, mixed with water to form a workable plaster. Portland cement, the same material that is the basis for the hardened properties of concrete used to build super-highways, bridges, and skyscrapers provides strength, durability, and toughness in Portland cement plaster. California local contractors face weather differences from Florida to Minnesota, traditional stucco is a proven system that works in all climates demand plastering.Portland cement plaster is applied either by hand or machine to exterior and interior wall surfaces in two or three coats. It may be applied directly to a solid base such as masonry or concrete walls, or it can be applied to a metal lath attached to frame construction, solid masonry, or concrete construction. Applied directly to concrete masonry, Portland cement plaster provides a tough 1/2-inch thick facing that is integrally bonded with the masonry substrate. When applied to metal lath, three coats of plaster form a 7/8-inch total thickness. A vapor-permeable, water-resistant building paper separates the plaster and lath from water sensitive sheathing or framing. Portland cement plaster has high impact resistance, sheds water, but breaths, allowing water vapor to escape. It’s a proven system that works in all climates.Traditional Stucco Is strong beautiful traditional Portland cement stucco provides a tough exterior that resists attack from woodpeckers to weed whackers. That inherent toughness is beautifully complemented by the variety of colors and textures available. Appearance is an important consideration in selecting a wall cladding. You can select a color and texture consistent with the message and image you wish to convey.Traditional stucco provides a strong, beautiful, low maintenance finish.Color is determined by selecting cement and aggregate color, and quite often modified by adding mineral oxide pigments to the plaster mix. In many areas, factory-prepared finish-coat products are available. Pre-pigmented packaged cements also can be used to achieve the desired stucco color or pre-weighed mineral oxide pigments can be added to the finish coat stucco during mixing.Texture is achieved by selecting aggregate size, controlling finish mix consistency, and using special treatment techniques during and after application of the finish coat plaster. Texture gives substance and character to the plaster surface. It can be used to provide highlights, depth, continuity, segmentation, and even achieve the look of a completely different construction material such as wood timbers, brick, or stone masonry construction. To confirm the suitability of a desired color and texture, be sure to ask your plasterer to provide a sample panel for evaluation prior to starting work. Portland cement plaster has a well documented history of proven performance in extreme climates from the desert southwest of Arizona, to the severe winters of Minnesota, to the hot-humid Florida summers. It performs in all climates. That durability is complemented by its versatility. Portland cement plaster provides an ideal finish or cladding for any building construction system including concrete, concrete masonry, brick masonry, wood frame, or steel frame. Portland cement stucco can be applied to any flat or curved surface either inside or outside. Don't Mistake Traditional Stucco For "EIFS" Portland cement plaster (sometimes called traditional stucco) should not be confused with the exterior insulation and finish systems (EIFS) or synthetic stucco systems that have become popular but more recently have been the subject of controversy as a result of performance problems, including water leakage and low impact resistance. Synthetic stucco consists of a polymer based laminate that is wet-applied, usually in two coats, to rigid insulation board that is fastened to the wall with adhesive, mechanical fasteners, or both. Polymer based (PB) systems, sometimes known as thin coat, soft coat, or flexible finishes, are the most common. The base coat for PB systems is usually only 1/16 in. thick and finish coat thickness is typically no thicker than the maximum sand particle size in the finish coat. While the PB skin repels water very effectively, problems arise when moisture gets behind the synthetic stucco and is trapped inside the wall. Trapped moisture eventually rots insulation, sheathing, and wood framing. It also corrodes metal framing and metal attachments. There have been fewer problems with EIFS used over solid bases such as concrete or masonry because these substrates are very stable and are not subject to rot or corrosion. Polymer modified mineral based (PM) exterior insulation and finish systems are sometimes known as thick coat, hard coat, or rigid finishes. The mineral base is Portland cement, while the polymer is usually an acrylic. PM systems have greater impact resistance than the PB systems, but are typically less than 1/3 the thickness of traditional three-coat stucco, demand plastering with stucco pros Traditional Stucco is Ideal For Concrete Wall Systems The durability and versatility of traditional Portland cement stucco provide a great finish for other concrete building systems including concrete panels, insulating concrete forms (ICFs), and autoclaves aerated concrete. Depending on the condition of the concrete surface, Portland cement plaster may be directly bonded to the concrete or applied to metal lath attached to the wall. When directly bonded to the concrete a dash bond coat or surface applied bonding
agent is typically needed to enhance the bond between the plaster and the concrete. When concrete surfaces are extremely smooth
or contaminated with excessive form oil metal lath is used as a plaster base. Metal lath can be mechanically attached to concrete,
ICF, or to autoclaves aerated concrete walls to provide a base for durable, traditional three-coat Portland cement plaster
exterior.Concrete masonry provides an excellent base for direct application of Portland cement plaster in 2 or 3 coats, consisting
of base coat(s) and a finish coat. The use of open-textured concrete masonry units promotes mechanical keying between the
plaster and base masonry wall. Because plaster and concrete masonry undergo similar volume changes, they are inherently compatible.Traditional
Stucco Works great fro Demand plastering. Portland cement plaster has been used over frame construction in the United States
since before the turn of the century, long enough to develop proven procedures for installation. When Portland cement plaster
is selected as the exterior surface for frame construction, metal lath is attached to framing members. Vapor permeable, water-resistant
paper is applied over sheathing before attachment of the lath. The paper protects the sheathing and interior of the wall demand
plastering from outside moisture intrusion without trapping moisture vapor in the wall. Furring dimples in self-furring lath,
furring nails, or other furring attachments hold the lath about 1/4 inch away from the sheathing, frame, or solid base wall.
This permits the Portland cement to penetrate lath openings and surround the metal strands, embedding them. As the scratch
coat plaster hardens, the lath and plaster become rigidly interlocked with the lath, essentially performing as reinforcement.
Encasement of the metal also protects the metal lath against corrosion.Lath may be expanded-metal lath, woven-wire lath, or
welded-wire lath. A variety of accessories are also available for use in different plaster installations. Movement joint accessories
isolate plaster panels from building movement and accommodate thermal- and moisture-induced volume changes in the finished
plaster. Flashing redirects moisture to building exteriors. Foundation weep screeds serve as a plaster stop and directs moisture
to wall exterior. The availability of different types of metal lath and accessories increases the versatility of Portland
cement plaster and contributes to its serviceability in many applications.
Demand Plastering
DP
|
|
||
|
|
||
|
|