essay 2-3 pages Cost & Estimating
Ssult89
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CSMT 441
Waterproofing
Lecture 13
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Water protection
• Damp-proofing and Water-proofing
• Shingles and Roof Tiles
• Roofing and Siding panels
• Membrane Roofing
• Flashing and Sheet Metal
• Roof Specialties and Accessories
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Damp-proofing and Water-proofing
• Damp-proofing resists dampness, but is not
designed to resist water pressure (painting the wall
with bituminous materials)
• Waterproofing resists the passage of water and the
hydrostatic pressure to which a wall or floor might
be subjected to (membrane waterproofing)
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Membrane Water-proofing
• It consists of a buildup of tar and membranes (plies) into a strong impermeable blanket.
• Plies (woven glass fabric, saturated cotton fiber, and tarred felts) provide strength and flexibility to the membrane.
• Unit: square (100 sf) – Check the Specs. for
• number of plies (2 to 5)
• the kind and weight of ply
• type of coating (tar or asphalt)
• the pounds of coating material
• the lap required over each strip of reinforcement
• and the type and thickness of protection coating
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Materials required for one square (100 sf) of
membrane waterproofing
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Roofing
• Roofing includes roof covering, insulation,
and roofing accessories (e.g., flashing)
• Pitched roofs are sloped to drain water to
the perimeter of the building
• Flat roofs are sloped to interior drains (1/8"
to 1/4" per foot)
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Roofing
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Roofing
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Roofing
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Shingle Roofing
• It is used in sloped roof (a slope of 3" or more per foot)
• Available in asphalt, wood, fiberglass, slate, aluminum, and steel
• Asphalt shingles (AS) are 12 and 15" wide, and 36" long. The exposure generally is 4, 4.5, or 5".
• AS are specified by the weight per square, fire rating, and resistance to wind
• Unit: Square (100 sf)
BCN 5618 12
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Shingle Roofing – Cont.
• Allow one extra course of shingles at the eaves (the first course must be doubled).
• Hips and ridges are taken off by LF and considered 1' wide.
• Waste ranges between 5 to 8%.
• 1.5 to 3 pounds of galvanized large-headed nails, 7/8" to 1 3/4" long are used per square.
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Underlayment
• Underlayment of building paper or roofing
felt is generally used
– unit: SF
– no. of layer and weight should be specified
– 5 to 8% waste.
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Tile Roofing
• Used on sloped roofs
• Made of clay or concrete
• Durable, attractive, but expensive
• is heavy and needs stronger supporting
system.
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Metal Roofing
• Preformed
– used on pitched roofs
– made of aluminum or steel (galvanized, painted, or coated with asphalt)
– fastened with self-tapping screws and neoprene washers to purlins.
• Formed
– used in sloped roofs with plywood and concrete base
– made from copper, tin, and lead
– flat sheet metals are joined by tool formed batten-seams.
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Flashing
• Flashing is used to keep water from getting under the roof covering and from entering the building wherever the roof surface meets a vertical wall
• It is needed in the perimeter of the roof and around penetrations through the roof.
• It is made of aluminum, copper, stainless steel, rubber, or plastic
– unit: no of pieces, LF with the width and thickness noted
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Manufactured Roof Specialties
• Gravel Stop- serves as termination of gravel at the edge of roof, as counter flashing, and as decorative strip
– unit: no of pieces, LF with the width, thickness, and material noted.
• Gutter and Downspouts (LF, material, size, thickness)
• Expansion Joints (LF, material, thickness, width)
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