Location of electrical appliances in residential building

Electrical appliances are those small home appliances which are used to get controlled output from electricity supply. Such as electrical switches, electrical power points, lights etc.
level of electrical appliance
Electrical Fixture
 We maintain a standard level/height for electrical appliances in residential building for user convenient. This level may vary in different countries. Here in Bangladesh, we follow the followings- 

Standard level for various electrical appliances:


Tube light: Let's start with light. Bottom of tube light holder in rooms, we keep at 7'-6" from finished floor level and it is 6'-6" in bath/toilet. If there is a mirror in bath/toilet then it will be on top of mirror.

Switch board: Bottom level of switch board is at 4'-6" from finished floor level.


Switch: Combined switch Bottom level of window AC is 5'-0" from finished floor.
Switch of split AC is kept at Switch Board level or at skirting level which is suitable.
Geyser switch will be at Switch Board level.


Power point: power points are often called socket. We use two types of sockets in residential building – 2-pin socket and 3 pin socket. Which socket is used for what - you know it yourself.
We normally put 2-pin socket at switch board. We also put a 2-pin socket at skirting level (1' from finished floor) for television power supply.
We maintain different level for different purpose for 3-pin socket. For general purpose, we put 3-pin socket at 1' level, for kitchen hood at 6' from finished floor level and for micro oven at 1' from kitchen work-top.


Calling bell: We put Calling bell at 7'-6" height from finished floor level.


Exhaust fan: We install Exhaust fan under false slab in toilet. Since we maintain 7'-0" height for false slab bottom so we can say exhaust fan top-level in toilet/bath will be at 7'-0" from finished floor level.
We don't make false slab in kitchen so the bottom level of exhaust fan will be at 7'-6" from finished floor.


Window AC: Bottom level of window AC is 5'-0" from finished floor if no beam interrupts. If beam interrupts that will be at beam bottom level.


Split AC: Indoor unit bottom level of split AC is 7'-9" from finished floor.


Wall bracket: Bottom of wall bracket, we keep at 7'-6" height from finished floor level.


SDB (sub distribution board) box: We keep top of SDB box at 7'-0" height from finished floor.


Intercom: We maintain 4'-6" level from finished floor for intercom set. That means it's at switch board level.


Others: We also maintain some other standards for electrical appliances. Such as; Distant between TV power point & Internet power point is 6".
Horizontal Distant between Dish Antenna line & TV power point
is 6".
Horizontal Distant between internet line & internet power point is 6" etc.


This standard level isn't unchangeable. It can be changed as per owner or client's requirement.

I know you are thinking that this blog is for civil engineers. Then why this electrical post is here! As a professional civil engineer, we often need to work on finishing project and to know this standard level is essential for finishing residential projects properly.



Architectural drawing sheet titles in building construction

Construction
A sample floor plan (Photo credit: Wikipedia)
In last post we discussed about "Types of drawing used in building construction". Each drawing type has many other drawing sheet of different names. Now we are going to discuss about drawing sheets under architectural drawing type.

The common architectural drawing sheets are:

  • Content sheet
  • Location map
  • Setting layout
  • Column layout
  • Floor Plan
  • Elevation
  • Section
  • Beam and Slab layout
  • False Slab plan
  • Door-Window schedule
  • Door-Window details
  • Part section and elevation
Content sheet: As we know content sheet is a summary sheet contains every sheet name and their page number. The page number of architectural drawing sheets generally marked as A1, A2, A3.... like this.

Location map: Location map contains the project location related to surrounding well-known place including location of roads.

Setting layout: This sheet shows the actual build up area of building related to plot area.

Column layout: Column layout shows the column position in building related to grid line.

Floor plan: This drawing shows location of bedrooms, bathrooms and kitchen etc. on floor. Normally one sheet of floor plan contains one floor plan and different sheet is used for showing different floor plan of building. Floor plan sheet also shows door-window placement of a floor.

Elevation: Elevation is the outside view of building. Each sheet of elevation contains one side elevation of a building.

Section: Section is a view of imaginary cut line through building. It shows construction details along cut line. Normally section is made both way of a building.

Beam and slab layout: This drawing sheet shows the beam location on slab, slab outline and related measurements.

False slab plan: It shows the false slab location inside building. It also shows the size and placement of cat door.

Door-window schedule: This drawing shows the measurement of doors and windows as chart.

Door-Window details: It contains elevation, section and description of doors and windows. It Also describes the materials to be used in door and window.

Part section and elevation: If any part of a building needs more detailing then those are shown in these sheets.

Sometimes architectural drawing also contains the drawings sheet of boundary wall. But most often it's supplied as separate drawing. Grill, railing etc. drawing sheet can also be included with architectural drawing. But it is better to provide it as separate sheet.

Types of drawing used in building construction

Different drawing is prepared for different purpose. Such as working drawing is prepared for construction project, drawing for approval is prepared for submitting to government agencies to approve and approved drawing is finally supplied to construction site.
Here we are discussing on construction drawings. It's also called working drawing. After review, justification and modification in various stages the drawing is approved for construction. Construction drawing should have detail measurement and clear section of every part of building. For this purpose different types of drawing used in building construction.

types of construction drawing 

Below are the common types of drawing used in building construction -

  • Architectural drawing
  • Structural drawing
  • Plumbing & sanitary drawing
  • Electrical drawing
  • Finishing drawing etc.
Architectural drawing: This type of drawing gives a complete view of building. It describes the location of a building and where to place every parts of building etc. It holds many other drawing sheets of different names. Such as plan, elevation, section etc.

Structural drawing: Its name describes about it. It explains everything about structure such as strength of different part of structure, structural material, placement, grade and size of reinforcement etc. It also contains many other different named drawing sheets inside it.

Plumbing and sanitary drawing: This type of drawings show the location of sanitary and water supply piping and fixture and how to connect every fixture etc.

Electrical drawing: This kind of drawings describe the location and details of electrical wiring, fixtures and sub-station etc. It also shows the electrical load calculation.

Finishing drawing: It includes all drawing about finishes and out looking of building such as tiles, marble granite etc. Sometimes this type of drawing included with architectural drawing.

As far as I know there are no fixed rules about how the drawings are categorized in construction. Yet the drawings are categorized for work convenience.


Did you find any other type of drawing in building construction? Please share your experience.

Checklist of Slab form work

No matter which type of shutter material you use for making concrete form work, the main purpose of concrete form work is same that is temporary support cast in situ concrete including all live load. So the purpose of checking form work is that the form is capable enough to carry the load till concrete gets desired strength. Another purpose of concrete form is to give hardened concrete a shape without loosing its quality.
Although purposes of concrete form work is constant yet form work checklist is different for different shuttering materials used in concrete form.
Here I'm sharing a checklist for a particular concrete form which we made in previous post "How to make slab form work using only steel shutter material".
Concrete form work checklist

Checklist of concrete form work for slab-

  • Check the centre-to-centre distance of props below 3 feet.
  • Check Steel props are properly tightened.
  • Check props are truly vertical.
  • Check scaffolding spacing is not more than 4 feet.
  • Small runner spacing is not more than 1 feet.
  • Check two inches over lapping is provided between plain sheet joint.
  • Check sheet joint are placed directly over small runner.
  • Check foam is used in every shutter joint to prevent water leakage. 
  • Check every plain sheet joint is made leakage proof by masking tape. 
  • Check Inside of form properly cleaned. 
  • Check oil is applied to form. 
  • Check no excess oil is available inside form. 
  • Check the slab level in all direction. 
  • Check horizontal bracing is used around periphery. 
  • Check no plain sheet slipped into beam. 
  • Check beams are straight and placed in position as per drawing. 
  • Check nut-bolt/shutter clip is fixed or tightened in every shutter hole. 
  • At last check the form work dimension as per architectural drawing.
Dear reader I made this list from my practical experience. I welcome you to share your experience.

How to make formwork for slab using only steel shutter material

Slab formwork with steel shuttering
Slab Form work

"Professionally built form work is must for producing quality concrete."

Many different methods are used to make form work for slab. It depends upon type of shutter material used for making concrete form. Such as you can use only "wood and bamboo" or only "steel shutter material" or combination of wood and steel shutter material for making concrete form work for slab. So, the making method of concrete form will differ for different shutter material. Here I am sharing a technique for making concrete form work using only “steel shutter material".

Form work for slab starts after finishing column casting. Column casting is done up to beam bottom level. However, everything is ok, required shuttering material is arranged and workers are ready. Now start making form work for slab.

Step by step procedure of making form work for slab using only steel shutter materials:

Step 1: First Take the desired slab level and mark it on column reinforcement. Practically level is taken before column casting. So start with that.
   
step 2: Fix the beam bottom between columns. Weld the beam bottom with column reinforcement. Give support to beam bottom with steel props. Spacing of props should not exceed 2.5 feet depending on beam span. Weld props with beam bottom to keep the props in place.
   
Step 3: Now fix the inner part of beam side with beam bottom by shutter clip or nut-bolt. Make sure foam is provided into shutter joint to make the formwork leakage proof.
   
Step 4: Put scaffolding on base plate. Spacing of scaffolding should be maximum 4 feet. Fix cross-bar with scaffolding to keep it in place.
   
Step 5: Use joint pin to put one scaffolding above another.
   
Step 6: Put U-head on the top of each scaffolding.
   
Step 7: Now start laying 4"x4" MS hollow box on U-head. Spacing of runner should not be more than 4 feet center-to-center. At this stage level the hollow boxes by adjusting U-head in accordance with marked slab level.
    
Step 8: After all big runner are leveled then start laying small runner (1.5” x 1.5” ms hollow box) perpendicularly on big runner. The center-to-center distance of small runner should not exceed 1 feet.
   
Step 9: Check the slab level all around again with water level.
   
Step 10: Now start laying plain sheet on top. Lapping between plain sheets should be minimum 2 inches. Keep in mind that If you place plain sheet parallel with small runner then keep every sheet joints directly on small runner.
   
Step 11: Now make the sheet joint water proof with masking tape.
   
Step 12: Apply oil to all shutter faces which will contact with concrete to avoid sticking concrete with form. You can use any shutter oil for this purpose. But I found 1:10 Mobil-diesel mix is better.

In this article I used only steel Shuttering material for making this slab form. It requires more skilled worker. Later I will write the procedure of making slab form using combination of wooden and steel shutter materials. So subscribe to RSS feed to get update.


Did I miss anything? Please let me know through comment.

List of steel shutter materials commonly used in building construction

Steel shutter is widely used concrete form work material because of its convenient to fix, remove and many time re-usability and also for its excellent concrete finishing virtue. Concrete form is made by combining different individual shutter materials. Such as wood, steel, fiber and plastic etc.

Below is a list of commonly used steel shutter materials-

  • Column/beam side
  • Beam bottom
  • Steel Props
  • Scaffolding
  • Cross bar
  • Base plate
  • U-head
  • Joint pin
  • Turn bolt
  • Runner
  • Shutter grill
  • Steel Beam
  • Nut-Bolt
  • Shutter clip
  • Plain sheet

A short description of each material is given below:

Beam/Column side: This is the part of main form work of beam or column. It is made by combining 16-18 SWG sheet, MS flat bar and MS angle frame with necessary holes for fixing nut-bold/shutter clip in required shape.
Steel column side for form work



Beam bottom: The procedure of making beam bottom is same as beam side.
Steel Props: it is vertical supporting tool used under beam. It also can be used as column strut.
Scaffolding: Scaffolding is the vertical supporting tool of slab form work. The height and width of it can vary as required. Commonly used sizes are 4'-0" x 4'-0" and 4'-0" x 5'-8".
Cross bar: cross bar is used to support scaffolding horizontally. The size of cross bar depend on the size of scaffolding.
Base plate: Base plate is used to support scaffolding by providing firm platform. It
is the most bottom part of slab supporting.

U-head: This is also a vertical supporting tool used above scaffolding to support runner.
Joint pin: Joint pin is used to joint scaffolding one above another to get the desired slab height.
Turn bolt: Turn bolt is used to pull up concrete form work.
Runner: Runner is a horizontal supporting tool. Normally different sizes of mild steel hollow box used as runner. Commonly used sizes are 4" x 4", 4" x 3", 3" x 3" and 1.5" x 1.5".
Shutter grill: Shutter grill is used below plain sheet. It is made by welding MS flat bar. Common size of shutter grill 2.5 x 2.5 feet.
Gril for slab form work
Shutter grill

Steel Beam: Temporary horizontal supporting tool used under shutter grill.
Shutter clip: shutter clip is used to fix two beam/column side.
Plain sheet: this is also horizontal supporting tool used above runner or shutter grill
for making slab form work. 16/18 SWG MS plain sheet is used for this purpose. Common size of plain sheet is 3’ x 6’ and 4’ x 8’.

Keep in mind that, there are various type and shape of same material available in the market. Here I am showing only common type steel shutter material available in construction industry. In my next post I'll share "how to make slab form work using steel shutter material" from this list. So please subscribe “RSS feed” to get update.

Which type of shutter material do you use. Please share your idea.

 

Copyright @ 2016 A Civil Engineer .