# PARAM VISIONS

All about civil construction knowledge- PARAM VISIONS

### Calculating the number of roofing sheets required for a shed. / Estimation & costing of a shed ( part 5 ).

Let us consider a shed of plinth size 8ft.× 10ft. as shown in the drawing.

Here, length of the shed L = 10ft., width W = 8 ft., height H1 = 9 ft., & H2 = 8ft.

Let us extend the roofing sheet length by 1ft. on the left & right sides of the shed, & by 1.75 ft. on the front & backside of the shed.

Now, we will calculate the area of the roof that should be covered by the roofing sheet.

Width side of the roofing sheet

Wr = [length of the shed+( roofing sheet extension × 2 sides)]

= [10 ft. + ( 1ft. × 2nos.)]

= 12 ft.

Length side of the roofing sheet

Lr = [sloping roof length of the shed + ( roofing sheet extension on back + front side)]

To calculate the sloping length of the shed, as shown above, we have to derive the hypotenuse of the triangle.

Sloping roof length

= √ ( 8ft × 8ft + 1ft. × 1ft.)

= √ 65 ft.

= 8.062 ft.

Roofing sheet length

Lr = 8.062 + (1.75ft. + 1.75ft.)

=  11.562 ft.

We will consider buying tata durashine roofing sheets for this shed.

The nearer standard length of the sheet for the calculated length (11.562) is 3660mm. or 12ft.

So we will go for 12 ft. length roofing sheets for this shed.

Now, the effective width of this sheet after overlapping is shown below.

Here, effective cover width We = 1015mm, total width Wt =  1072mm.

The number of roofing sheets required

= [width side of the roofing sheet for the shed ÷ effective width]

= [Wr ÷ We]

By converting the effective width unit into ft.

(1mm = 0.00328084ft.)

We = [1015mm × 0.00328084]

= 3.33 ft.

Number of roofing sheets

= [12ft ÷ 3.33 ft.]

= 3.6036 sheets

By rounding off the sheets, we will buy 4 numbers of 12 ft. length roofing sheets to cover this shed.

Now, what will be the maximum roofing width that you can cover using these 4 sheets at their given effective cover width?

i.e. [effective cover width  × 4 nos. of roofing sheet]

=   [1015 mm.× 4 nos.]

= 4060 mm.

= 13.3202 ft.

If you said yes, then you have done one of the 3 mistakes in roofing sheet calculations.