What is scratch and brown base coat stucco?
QUIKRETE® Scratch and Brown Base Coat Stucco (No. 1139) is a portland cement based stucco used for construction and repair of stucco walls. Complies with ASTM C 926 requirements for cement based plaster. Scratch and brown coat in a three coat stucco application
What is the difference between a scratch and a brown coat?
Characteristics: The brown coat surface is much smoother than the scratch coat and is gritty to the touch but flatter and looks more appealing than the scratch.
How long does it take for scratch and brown coat to cure?
Cure Time: The brown coat requires a lot more time to cure (28 days is recommended). You want the scratch and brown to be fully cured before applying the finish coat to minimize cracking and ensure the greatest possible strength.
What is scratch coat?
Definition of scratch coat : the first coat applied in plastering having lines scratched on its surface to improve the bond with the next coat. — called also first coat.
What is brown coating?
brown coat in American English noun. (formerly in fresco painting) a second coat of plaster, somewhat finer than the first coat, applied over the entire surface and on which the drawing for the fresco is done; arriccio.
How long do you wait between scratch coat and brown coat?
Cure Time: The scratch coat should be allowed to moist cure for a period of 3-5 days. This allows the cement to become hard enough to gain most of it's strength before the brown coat is applied. Cure Time: The brown coat requires a lot more time to cure (28 days is recommended).
What is scratch coat stucco?
Next comes the scratch coat, which is a base layer of field-mixed Portland cement, sand, lime, and water with a series of horizontal lines scratched into it. Then comes the brown coat. This layer is applied with a darby, or long trowel, to make sure the cement is applied evenly.
What is stucco scratch and brown coat?
QUIKRETE® Scratch and Brown Base Coat Stucco (No. 1139) is a portland cement based stucco used for construction and repair of stucco walls. Complies with ASTM C 926 requirements for cement based plaster.
What is a scratch coat for tile?
The scratch coat consists of a layer of plaster that is grooved while wet. Scoring, or scratching, is done with a notched trowel or other tool with a serrated blade. Each score provides an area for the next coat of plaster to adhere to and create a solid bond.
Is scratch coat necessary?
A scratch coat will be needed when metal lath is used. This step is not necessary when applying stone veneer to a cleaned concrete, masonry, or stucco surface.
Should I wet the scratch coat before applying brown coat?
It is also recommended to pre-wet the surface of the first or second coat before installing the brown or finish coat; this will improve bonding between the layers and improve the scratch coat's long-term strength gain.
How thick should scratch coat be?
The scratch coat should be 3/8" thick. Force it through the wire mesh so that it fills the ¼" gap between the mesh and wall completely. 3. Smooth the scratch coat with the trowel.
What are the three coats of stucco?
Basically the three coat system consists of paper and wire, a scratch coat, a brown coat and a finish, or “top” coat. This is why it is called a three coat system, lath, scratch and brown.
How thick is stucco scratch coat?
Traditional Hard Coat stucco is 7/8 inch thick Scratch coat 3/8 inch. Brown coat 3/8 inch. Finish coat 1/8 inch.
Do you wet scratch coat?
Moist Curing. This involves using a misting hose to add additional moisture to the scratch coat once it's been applied to the frame. This helps improve the strength of the scratch and also prevents other coats from sliding off during application.
What is SPEC mix stucco?
SPEC MIX Scratch and Brown Preblended Stucco is designed for use over galvanized, expanded metal lath or solid base surfaces such as masonry or precast concrete. The material can be hand applied or machine sprayed. Installation of stucco over these surfaces shall be in accordance with ASTM C 926, and all applicable building codes. Dampen all surfaces to receive stucco prior to application. An expansion joint should be installed at dissimilar materials. Stucco shall be used and placed in final position within one hour after initial mixing. Variation of water content and retempering will affect strength, consistency and uniformity. SPEC MIX products must be kept dry, covered and protected from weather and other damage.
How to make stucco with nitrile?
WEAR IMPERVIOUS GLOVES, such as nitrile.#N#1. Add approximately 1.2 to 1.5 gallons (4.5 to 5.7 liters) of clean water into the mixer for each 80 lb (36.2 kg) bag .#N#2. Slowly pour the contents of the bag (s) into the mixer.#N#3. Mix for 5 minutes until a firm, workable consistency is achieved. Avoid over mixing as this may affect the integrity of the finished product.#N#4. If more water is needed, add small amounts at a time and continue to mix until the desired consistency is achieved. Do not exceed a total volume of 1.75 gallons (6.6 liters) of water for each 80 lb (36.2 kg) bag.#N#5. Keep mixing times and procedures the same every batch. Over mixing may entrain air, which can adversely affect plastic and hardened stucco properties. Prepare only as much mix as can be applied in one hour.
What is SPEC MIX?
SPEC MIX® Scratch and Brown Preblended Stucco is a dry, preblended cement-based product designed to be used as the scratch and/or brown coat in a three-coat stucco application. This product also can be used as the first coat in a two-coat application for exterior stucco applications. The final wall system will produce a nonload-bearing, aesthetically pleasing exterior veneer or interior finish on concrete or masonry walls, stud walls or metal buildings.
How thick is a scratch coat?
It is applied using a hawk and trowel and scratcher, spread evenly to achieve a depth of 3/8 of an inch thick. After the cement is on the wall, the scratcher is used to create horizontal lines in the stucco. This helps the brown coat stick to it.
What is a three coat stucco?
The three coat system is the original stucco process , which consists of water and paper, a scratch coat, brown coat, and a top coat. In industry terms it is just latch, scratch, and brown. The top coat itself is not considered a step since it is required on every type of application used.
What is Stucco?
Stucco is a decorative coating used for walls, ceilings, and other surfaces to give it a particular finish and texture. It can be used both indoors and on the exterior of a building to provide an additional design element. However, the stucco that is used for exterior applications is not the same as the kind used for interiors. Stucco that is applied on the exterior of a home or building is designed to withstand the elements, including direct sunlight and inclement weather.
What is the difference between surface bonding cement and stucco?
Although surface bonding cement is comparable to stucco, the main difference is the glass fibers and special additives. Surface bonding cement features an acrylic fortifier and fiberglass that adds strength and flexibility to the application. Additionally, surface bonding cement comes in premixed bags that tend to be easier to work with, as the recipe is already calculated and all you have to do is add water! Find out if you can use joint compound on cement board.
Can you paint stucco?
Stucco, on the other hand, offers a very traditional, straightforward finish that is more decorative than using surface bonding cement. Not to mention, the material works exceptionally well for southwestern-style structures. Since stucco is made from a mixture of cement, silica, and lime, it comes with much of the same benefits as surface bonding cement, or concrete. Like concrete, you can paint stucco your preferred color.
