building construction Paper 3 WASSCE (PC 2ND), 2018

Question 1

 


SPECIFICATIONS


FOUNDATION:  675 x 225 concrete strip foundation laid to a depth of 900 below the ground level.

 

FLOOR: GROUND FLOOR


Earth filling.
Hardcore 300.
Concrete slab 150.
Cement sand screed 25.
FIRST FLOOR
Concrete slab 150;
Cement-sand screed 25.

 

WALLS:  STRUCTURAL WALLS


450x225x225 sandcrete hollow blocks with12 motar rendering on both sides.
SCREEN WALLS
100x150x100 perforated blocks.

 

BEAMS/LINTELS
AND COLUMNS:  225 x 225 reinforced concrete.

 

ARCHES:  All arches are semi-circular reinforced concrete type.
Arch 1:  Height – 2400.


Span – 1888.


Arch 2:  Height – 2400.


Span –   1850.


Arch 2:  Height – 2400.


Span –   3000.

 

DOORS:  D1 – 1200 x 2100 glazed metal door.            
        D2 – 900 x 2100 panelled wooden door with 100 x 75 hardwood timber frame.


D3 – 750 x 2100 panelled wooden door with 100 x 75 hardwood timber frame.

 

WINDOWS:  All windows are glazed aluminium sliding type.


W1 – 1200 x 1200  (2-bays).
W2 –  900 x 600 (2-bays).
W3 – 600 x 600  (2-bays).

 

PORCH/BALCONY: Metal balustrade 900 high measured from floor level.

           
THRESHOLD STEPS: FRONT


Rise – 150
Tread  – 300
Width – 4000.

RIGHT SIDE
Rise  – 150
Tread – 300
Width – 1200.

ROOF: Double pitched timber roof with long span aluminium roofing sheets

.
Eaves projection – 600
Pitch  - 20º
Rise - 2000.
Height from ground floor to ceiling – 3000.
Height from first floor to ceiling- 2800.

 

 

To a scale of 1:50,  draw the detailed section X – X of the building from the foundation to roof.


Observation

 

 

A good number of candidates did well by:

- showing the substructural elements ( i.e earth filling, hardcore filling, concrete floor slab and mortar screed finish ) with conventional symbols corectly;


-identifying  in details, the timber roof  members and labelling the key parts.
- indicating the finished ground level.

 

However, many of them failed to:


- show the correct door type, (that is some showed flush door type instead of panelled door specified
- construct geometrically, the semi-circular arch;
-hatch the walls in section.

The expected response to  question 1 is as given below: