BUILDING TECHNOLOGY I

1.WATERPROOFING AND DAMPPROOFINGA mortar or concrete is considered impermeable when it does not permit passage or flow of water through its pores or voids.

The absorption of a mortar or concrete is the property of drawing in or engrossing water into its pores or voids by capillary action or otherwise.

If the pores or voids between particles are sufficiently large and connected from surface to surface of the wall, the concrete will be permeable to water.

If the pores or voids are very minute, but connect with one another, theoretically they may act as capillary tubes, but the capillary forces will tend to hold the water and prevent the passage of water. 1.01WATERPROOFING OF CONCRETE

Impermeability through a Dense Concrete Accurate grading and proportioning of the concrete materials in order to secure a concrete so dense as to be waterproof.

Waterproofing Coatings and Washes Applying waterproof coatings or washes to the concrete after it is on place.

Integral Waterproofing CompoundsMixing foreign substances with the concrete.

Membrane WaterproofingSurrounding the concrete with layers of waterproofing materials.1.01WATERPROOFING OF CONCRETEThe various methods of waterproofing concrete may be classified as follows :1.WATERPROOFING AND DAMPPROOFING

Impermeability through a Dense Concrete 1.01WATERPROOFING OF CONCRETE1.WATERPROOFING AND DAMPPROOFINGPortland cement mortar and concrete can be made practically waterproof or impermeable without the use of any integral waterproofing materials; but in order to obtain such impermeable concrete or mortar considerable care should be exercised in selecting good materials :Well-graded sands containing considerable graded fine material are preferable for making impermeable concrete, or fine material in the form of hydrated lime, finely ground clay, or an additional quantity of cement will be of value. The consistency of the concrete mixture should be wet enough so that it can be puddled, mixture should be well spaded against the forms to avoid the formation of pockets on the surface.Care should be taken not to over trowel which may cause erasing the coating will be effective.

Defective workmanship, resulting from improper proportioning, lack of thorough mixing, separation of the coarse aggregate from fine aggregate in transporting and placing the mixed concrete, lack of density through insufficient tamping or spading, improper bonding of work joints .

The use of imperfectly sized and graded aggregates.

The use of excessive water, causing shrinkage cracks and formation of laitance-seams .

The lack of proper provision to take care of expansion and contraction, causing subsequent cracking .1.01WATERPROOFING OF CONCRETE1.WATERPROOFING AND DAMPPROOFINGPermeable concrete results from :

Alum and soap mixtures applied in alternate mixtures (known as the Sylvester process), which penetrates the pores of the concrete forming insoluble compounds due to chemical action between the alum and soap solutions, and these compounds prevents percolation. - use in proportions of gal. of soap to 1 gal. of water, and 2oz. of alum to 1 gal. of water, both substances to be perfectly dissolved in water before using.

- should be applied with a soft, flat brush (one for each solution), the soap boiling hot and the alum solution at 60 to 70F. 1.01WATERPROOFING OF CONCRETE1.WATERPROOFING AND DAMPPROOFINGWaterproofing Coatings and Washes

The materials employed as surface coatings may be classified as follows :

Alum, lye and cement washes .

Cement grout, with or without the addition of water-repellants.

1.01WATERPROOFING OF CONCRETE1.WATERPROOFING AND DAMPPROOFINGWaterproofing Coatings and Washes

Paraffin and other mineral bases, applied cold in solution or prepared in melted.

Miscellaneous materials of unknown composition sold under various trade names.

Specially prepared bituminous products, e.g., FLINT-KOTE, JOHN-MANSVILLE, etc 1.01WATERPROOFING OF CONCRETE1.WATERPROOFING AND DAMPPROOFINGWaterproofing Coatings and Washes

Asphalt emulsions - Generally called Asphalt Base Clay Emulsions, minute asphalt particles dispersed in water and maintained in suspension (until applied) by a mineral colloid emulsifying agent. When the water vehicle evaporates, resilient reinforced weatherproof film remains which resist the passage of free water but allows movement of water vapor through the film and are classed as breathing films.Cutback Asphalts - composed of a variety of products from thin liquids to heavy paste, often one or more asphalts dissolved in solvent are filled with minerals and fibers to meet requirements of different coating uses and provide tough, durable films resistant to the passage of water vapor.

Integral Waterproofing CompoundsThese are manufactured and sold under various trade names, and are available in powder or liquid form, e.g.:1.01WATERPROOFING OF CONCRETE1.WATERPROOFING AND DAMPPROOFINGSAHARAPOZOLITHAQUELLATruscon ZILICONANTI-HYDROThe addition of the integral waterproofing compounds will not, however, compensate for lean mixtures, nor for poor materials, nor for poor workmanship in the fabrication of concrete

Membrane WaterproofingLayers of waterproofing materials used in this method range from ordinary tar paper laid with coal-tar pitch to asbestos or asphalted felt laid in asphalt. 1.01WATERPROOFING OF CONCRETE1.WATERPROOFING AND DAMPPROOFING

Sheet Metal Roofing2.01TYPES OF ROOFING2.PREFORMED ROOFINGGalvanized Iron Roofing various corrugations and rib sections.Aluminum Roofing various corrugation and rib sectionsPlastic RoofingPlastic various corrugation and rib sectionsPolycarbonate corrugated and flat sheetsTile RoofingClayConcreteShinglesWoodTar

Sheet Metal Roofing2.01TYPES OF ROOFING2.PREFORMED ROOFINGGalvanized Iron RoofingCorrugated galvanized iron sheets are manufactured in lengths of 5 to 12 ft. in 1 ft. increments, the 8 ft length being the most commonly used.Width of sheets is 32. Each sheet has 10 corrugations with a pitch of 3. For roofing, Ga. 26 is generally specified, Ga. 24 is preferred.Galvanized iron sheets are also sometimes used as siding for industrial buildings. When used as siding, courses shall be lapped at least 6.

Sheet Metal Roofing2.01TYPES OF ROOFING2.PREFORMED ROOFINGAluminum RoofingCorrugated aluminum is rigidized sheet fabricated of special aluminum alloys specifically developed for this purpose. Has a high insulating value and is about one-sixth lighter than similar materials. Is silvery in color, strong and does not stain adjoining materials. It reacts, however, with dissimilar materials, lead-base paints green or damp wood, certain wood preservatives, lime mortar, concrete, and other masonry materials and must be insulated from contact with these materials .Width of sheets are 32-5/8, 32, 31-1/2, 31-1/8, and 30-5/8; lengths are from 6 to 12 ft. in 1 ft. increments. Number of corrugations for 32 sheets and wider is 12; sheets of narrower width have 10 corrugations.

Plastic Roofing2.01TYPES OF ROOFING2.PREFORMED ROOFINGCorrugated or Ribbed RoofingCorrugated sheets are manufactured in in same widths and lengths as Metal Sheet Roofing.Metal reinforced plastic roofing is available.Ideally used in sites of high salinity levels.Sheet RoofingPolycarbonate Sheets.Ideally used in greenhouses, patios, outdoor sheds, and skylights.

Tile Roofing2.01TYPES OF ROOFING2.PREFORMED ROOFINGClay TilesConcrete Tiles

Shingles2.01TYPES OF ROOFING2.PREFORMED ROOFINGWood ShinglesTar/Asphalt Shingles

is a black substance available in solid, semi-solid, or liquid states at normal temperatures.

composed of mixed indeterminate hydrocarbons, appreciably soluble only in carbon disulfide or other volatile liquid hydrocarbon.

used for sealing built-up roofing, and joints and cracks of concrete pavements. Bituminuous Cement3.01TYPES OF JOINT SEALANTS3.JOINT SEALANTS

Silicone Sealant3.01TYPES OF JOINT SEALANTS3.JOINT SEALANTS

End of Div 07 THERMAL AND MOISTURE PROTECTION