I'm here again to present to you my ideas on how to design and construct an economical and aesthetically pleasing roof in Nigeria.
for this topic, i will be using one of Harney projects ( podosci and abdulwastecx) ongoing project as a case study.
this thread will try to shed lights and educate prospective home owner on how to choose floor plan design that will be pleasing in the eye, economical and will be durable over a long period of time.

case study one: construction of timber roof truss for a confidential nairalander
contractor : harney projects
Duration of roof work : nine days (including two Sundays)
Location : confidential

Locked and loaded.

I like how you guys do your thing by interjecting new ideas into your work.

Here is the house before we start renovation

here is what we are looking to achieve

Before we could start the roof work, due to the complex nature of the roof, we have to do a simple roof design sketch showing all the "roof tie beams .

here is the roof tie beam sketch

here some general information and properties of hip roof ( German roof).
1.All the ridges and valleys (gutter) should be at 45 degree to the edge of the building
2.All the ridges and valleys (gutter) should be parallel to one another.
3. A reasonable spacing of 1.2m (4ft) should be adopted.

bill of quantities for the roof truss work
2"(50mm) x 4" (100mm) hard timber for rafter, brace, king post and tie beam about 800nr
2" (50mm) x 3" (75mm) hard wood for purlin of about 1200nr
2"(50mm) x 2" (50mm) for noggin

General roof properties:
1. number of inter corners (gutter, valley) =7nr
2. number of external corners ( ridges ) = 11nr
3. the longest dimension across a potential king post = 16.54m

step; Determination of roof height = highest king post
the highest king post is determine using simple ''hypotenuse theorem"
assume height =h
length of the longest side = L

solution, the opposite = h, adjacent = L/2
I wanted to use a vertical slope of 35degree ( because i wanted a simple and medium high roof)
h = L/2 x tan 35 = 19ft ( note , L/2 = 27'2'')

here are the tie beams

Due to the complexity of the roof, the height of building vary from the widest side to the narrowest side. Here are of the examples of such differences in height

After all the king post have been placed and brazed through the help of builders plumb, the rafter are then nailed.
It is important to always start the hanging of rafters from either the ridge or valley.
this ridge/valley is then braced both laterally and vertically through the use of line.
A line is then connected between two ridge or between ridge and gable to serve as a level line used to control all other rafters in between

the next step is the brazing of the rafter. The rafter braze is spaced at 5ft center to center.

Next: nailing of purlin. The purline spacing is a function of the type of roofing sheet used.
For stone coated roofing sheet = spacing of 14 1/4'' or 14''
for aluminum long span step = 450mm
for long span plain roofing sheet = 900mm

Finally, the roof connector is attached to the roof truss through the tie beam

Here is the finished roof truss

Here is the front view of the roof

EgunMogaji:
Locked and loaded.

I like how you guys do your thing by interjecting new ideas into your work.

moi aussi.

EgunMogaji:
Locked and loaded.

I like how you guys do your thing by interjecting new ideas into your work.

Thanks sir..

Good job

Very detailed, I like this roof. Good work.

Nothing to say.
Weldone Prof.

spyder880:
Very detailed, I like this roof. Good work.

Thanks sir.... From the veteran itself

smiley001:
Nothing to say.

Weldone Prof.

Thanks sir.... I'm a learner oooo

Installation of roofing sheet.
Roofing sheet type :stone coated tiles

abdulwastecx:
Before we could start the roof work, due to the complex nature of the roof, we have to do a simple roof design sketch showing all the "roof tie beams .

here is the roof tie beam sketch

hey man. thanks for the sketch. But how do u determine the shape of the roof from a house plan? I was making a house plan in autocad & I wanted to overlay the roof plan but I was stuck cos I don't know how to deterimine the ridges & other components of the roof… In your sketch, how did you come about such design of the roof even?

abdulwastecx:
here is what we are looking to achieve

These drawings what were they done with? Autocad?

cant wait to join you on this project.. thanks for your recommendation

Miscellaneous:

These drawings what were they done with? Autocad?

With Autocad I

Miscellaneous:


hey man. thanks for the sketch. But how do u determine the shape of the roof from a house plan? I was making a house plan in autocad & I wanted to overlay the roof plan but I was stuck cos I don't know how to deterimine the ridges & other components of the roof… In your sketch, how did you come about such design of the roof even?

Here are some tips for hip roof.
Shape of the roof is govern by shape of the floor plan, size of the plan etc.
Rule 1. Your ridges/gutter(valley) must all be parallel and must be at angle 45 degree to the building corners

abdulwastecx:


Here are some tips for hip roof.
Shape of the roof is govern by shape of the floor plan, size of the plan etc.
Rule 1. Your ridges/gutter(valley) must all be parallel and must be at angle 45 degree to the building corners

Thanks very much. This statement really helped me think: "Shape of the roof is govern by shape of the floor plan, size of the plan"