7. ROOFING WORK
7.1 Scope of work
furnish all labour materials and equipment for the complete installation of roofing works with insulation as indicated on the do-awing and specified herein.
7.2.1 Asphalt felt
Asphalt felt shall be asphalt saturated felt conforming to the requirement either of
1313-1 D226, B,S 747 or Iraqi standard specifications-Felt shall be 3Pty Pelt consisting of bituminous substance reinforced with fiber glass and two layers of building papers with fine aggregate,,
7.2.2 Asphalt primer
Asphalt primer shall conform to the requirements of ASM D41 of local standards specifications using natural asphalt flux with pertroleum asphalt, andlet down with selected solvent, to produce maximum adhesion to prime suface and subsequently- applied coatings.
7.2.3. maMic waterproofing material
mastic water proofing materials shall be specific emulsion type mastic water proofing materials, such as flintkote or equivalent to be approved by the Engineer.
7.2.4 Birth filling
The materials used for roof earth fills should be free from lump, stones and of an approved quality. Pilling materials should be free from foreign natter, cuch q,s nymphs of insect, rubbish of any kind, gavel and soluble salts. Ekrth fills shall be compacted very well and shall be of 100mm average thickness to form the slopes to drain water.
7.2.5 Precast concrete tiles
000mm as aright angleshape, the vertical and horizontal joints for skirting shall be cleaned primed and filled with mastic as described above.
Styropor for insulation of the roof shall have a thickness of 40mm, with thermal conductivity at 90 F° as ( 0.2 BTu /FT-HR,F°)
7.3 Built _ up Bituminous roofing system.
7.3.1 Hoofing system shall consist of the following layers:
a. Asphalt primer ( not less then 0.3L/m )
b. Asphalt ( thickness must be not less than 12mm). c. Two layers 3Ply of asphalt felt.
d. Insulation ( styropor)of 40 mm thickness
e. Clean earth filling of 100mm avarge thickness
f. Precast concrete tiles of 300 x 800 x 40mm and 20.0.x150x80Qnra for skirting with mastic jointing.
7.3.2 All surface receiving built _ up bituminous roofing must be clean free from dirt, dustf oil grease, mortar spatter and other foreign matters and must be completely dried out before roofing is applied.
7.3.3 all sharp edge projecting from surface shall be chipped and ground smooth. All in - and - out corners and angles of deck and a butting walls or vertical surfaces shall be trowelled with cement mortar with radius of apjxreicJ 50mm.
7.3.4 fiver, asphalt primer apply auniform coating of not asphalt followed by layer of
3ply asphalt felt over entire roof and anther layer in opposite direction. Each asphalt felt shall be laid free from wirniles and buckles and lapped over proceeding layer with a minimum length of 150mm.
7.3.5 Pelt shall be applied to the vertical surface of parapet continuously from the horizontal surface if practical, or separate felt shall be applied over lapping a minimum of 2 200 mm with horizontal felt layers.