Visaka Logo Gray

The perfect Shelter

Fibre Cement Roof

Our Journey so far

Visaka - A name that is synonymous with quality and strength, prides itself on the excellence of its products, its superior technology and most of all its professional expertise. All this combines to confirm the undisputed fact that Visaka’s products are highly appreciated for their economy and durability. Visaka's high-tech Fibre Cement plant is a fully automated factory incorporating the latest and most sophisticated technology, resulting in consistency in physical properties and strength, which far exceeds the standards prescribed by I.S.I.

Year of Establishment Established in 1981, our 1st factory commenced production of cement sheets in 1985.
Site Location Patancheru, Telangana
Production Quantity (Annual) Initial Capacity (1985)- 36000 tons Current Capacity (2015)- 802000 tons
Factories 8 plants across India
Machinery Equipment Procured from renowned Engineering groups, our machinery and equipment is top-of-the-line, with periodical inspection and maintenance
Annual Turnover FY: 2015-16 About Rs 1000 crores


ISI Specification
ISI SPECIFICATION TECHNICAL DATA
Standard lengths in (Metres) 3.00, 2.75, 2.25, 2.00, 1.75, 1.50 Tolerance (in mm)
+5 -10 +Free -0.5 +6 -2 +3 -5 +10 -5 +10 -5
Maximum unsupported overhang 300 mm
Thickness 6 mm Maximum Purlin Spacing for roofing 1.4 M
Pitch 146 mm Maximum Rail spacing for Vertical cladding 1.7 M
Depth 48 mm Section modulus ZB:75 cm3 ZT:85 cm3
Overall Width 1050 mm Moment of Rupture 200 kg/cm2
Effective Width 1010 mm Running Metres per tonne 78 (approx)
Minimum End lap 150 mm (for slopes 180 and above) Colour Light Grey


Economical Sizing & Estimating For
Visaka Crrugated Sheets & Accessories
Sizing

a) For Roof 1) Let us assume the slope length is L metre. 2) To cover this length, minimum number of sheets required N Where N=L-0.200/2.8 (a whole number). 3) Maximum lap loss is M metre Where M= (N-1) x 0.200. 4) Maximum sheet length required is P Where P = L + M => L + (N-1) x 0.200 (rounded off to next digit divisible by 0.25). 5) Once P is obtained, sizing should be done keeping the number of sheets at N. 6) check if the slope can be covered by (P - 0.25). 7) Check that the number of purlins does not exceed - K Where k= L - ( a1 + a2) / 1.40 + 1 (a whole number) Where a1 = distance between the eaves purling and the eaves edge in - Metre. Where A2 = distance between the eaves purling and the eaves edge in - Metre. b) For Wall Cladding Most economical length is 1.75 M. which allows a Rail spacing of 1.6 M..


Estimating

For both Roof & Wall Cladding. Number of sheets in a particular row N = L - 0.04 / 1.01 (a whole number) Where L = Length of the shed in Metre.


Accessories
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Close fitting Adjustable Ridges AVS2
To close the roof at the ridge
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Apron piece AVS2
To cover the angle formed between sloping roof and vertical cladding or walling
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North light Ridges AVS5
To cover the ridge of north light of roof
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Barge Boards AVS6/6
To cover the verge of a roof or corners of cladding
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North light Curve AVS9
To cover the north light roof at ridge
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Serrated Adjustable Ridges AVS10
To close the roof at ridge
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Roof lights AVS
To allow light inside from the roof
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Ridge Finials AVS11
To close the ends of the ridge
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Ridge Finials AVS7
To close the end of the ridge line. Will go only with AVS2 ridges

Procedures
Estimating Roofing Accessories

The covering capacity of the following Roofing Accessories corresponds to the width of the sheets :

  • All Ridges (number in pairs)
  • North light curves (in numbers)
  • Apron pieces (in numbers)
  • Eaves Filler pieces (in numbers).

Fixing Procedure

fixing procedure should be followed as per is 3007/1964 : code of practice for laying of asbestos cement sheets - part 1, corrugated sheet:

  • Before laying of sheets check the purlin spacing and the length of the sheets to ensure that the arrangement of sheets will provide the required end lap (min. 150 mm as shown infig 5.) and the specified overhang at eaves (max. 300 mm and at the ridge (normally 75 mm).
  • The sheets to be laid with the smooth side facing the weather.
  • For left to right fixing, start at eaves with sheet 'a' - (fig. 1) to the purlin with downward corrugation on left and upward corrugation on right, so that the downward corrugation of the next sheet can site on it.
  • Next place the sheet 'b' which is mitred at the bottom right hand corner in the manner shown in fig 2.
  • All other sheets in this slope including ridge sheet 'c' should be fixed similarly.
  • Start the next tier with sheet 'd' which is mitred at the top left hand cornet. make sure that the side lap (1/2 corrugation min.) is correct. mitring is done as shown in fig. 3
  • Continue with sheet 'e' which is mitred at the top left hand corner and bottom right hand corner.
  • At ridge fix the sheet 'f' which is mitred at the bottom right hand corner.
  • Fix 'g' & 'h', which are mitred on the top left hand corner.
  • Fix 'i' without mitring. (whenever four sheets meet at a lap joint the intermediate two sheets are to be mitred).
  • The bolt should pass through the second and last corrugations, i.e. bolt distance between two successive sheets should be 279.4 mm (fig 4.)
  • For 8mm dia hook blots (conforming to is 730-1978) - 10 mm dia hole should be drilled (never punched), on the crown of the corrugation.
  • Bitumen washer, g. i. washer to be used while fixing the sheet with hook blots.
  • Hook bolts should not be tightened too tightly.
  • Sheets should be fixed with hook bolts at intermediate purlins also.
  • Mitring or cutting of sheets should be done with an ordinary carpenters saw only.
  • Always use a cat ladder during installation for safety and better results.

Fixing of Visaka As-10 Serrated Adjustable Ridges
  • Commence from right hand verge - lay a few inner rolls r1 : the rolls should sit flush with the whole sheets in a straight line (fig. 6).
  • Commence laying r2 (outer rolls) - on the opposite slope and in the same direction of r1, so that the small serrations rest with the side lap of the sheets, ensuring a snug sitting of r2 over the roofing sheets and also staggered jointing between r1 and r2.
  • The ridge is secured with the same bolt which is used on the roofing sheets at the right purlin.

Contact Us
CORPORATE OFFICE
"Visaka Towers", 1-8-303/69/3, S.P.Road, Sec-bad-003.
Tel: 091-040-27813833, 27813835
Fax: (091-040)-27813837
REGD.OFFICE & FACTORY : (A.C.DIVISION I)
Survey No. 315, Yelumala Village, R.C.Puram Mandal, Medak Dist-502 300(A.P)
FACTORY : (A.C.DIVISION II)
Behind SUPA Gas, Manikantam Village, Paramati - Velur Taluq, Namakkal Dist - 637 207. Tamil Nadu.
FACTORY : (A.C.DIVISION III)
Plot No. 11& 12, 18 to 21 & 30, Changsol Mouza, Banki Bundh, G.P. No: 4, Salboni, West Midnapur, West Bengal - 721 101 Tel : 03227- 285852 / 285851
FACTORY : (A.C.DIVISION IV)
No. 27/1, G. Nagenhalli Village, Kora Hubli, Dist & Taluk : Tumkur, Karnataka. Tel: 0816-3090393
FACTORY : (A.C.DIVISION V)
Village Kannawan, P.S. Bacharawan Tehsil : Maharaj Ganj, Raibareli Dist, U.P - 229 301
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