What is electrical concealed wiring? This is a type of electrical wiring, that ensures that all the materials used are hidden.
When I say that all the materials are hidden, I refer to conduits, metal boxes loop inboxes and cables. This is regardless of where the materials are concealed. When doing concealed wiring, you conceal the conduit pipes and cables in walls, ceiling and the concrete slab and deck.
How to do concealed wiring.
Before you start to do concealed wiring works, it is important to know what will be installed in each room of the house or the building. In organised scenarios, this is taken care of by the electrical schematic drawing for the building. An electrical drawing is going to show you what should be installed in each room of the house building.
In instances where there is no electrical schematic drawing, you should work closely with either the electrician or technician that is doing the works.
As a Technician on the ground, you should ask the owner of the house or building what he wants to install in each room. For this process to be effective, you should do this exercise on site.
Concealed wiring in walls
Here I am going to guide you on how to do concealed wiring in walls. The first step is to mark the positions where you will pass the conduit pipes. You don’t mark the positions of conduit pipes only.you mark the positions for switch boxes, sockets outlets and distribution boards also.
After marking the positions where conduit pipes and switched boxes will be, you proceed to chisel the walls. You use an angle grinder to cut the walls. A hammer and chisel are needed to remove the cut debris from the wall.
The walls are cut what follows? You start to mount the conduit pipes and various boxes. You install conduit pipes by putting them in the cut walls, then you cover or Barry the conduit pipes using mortar made with sand and cement.
To prevent cracks from developing in the cut walls, you can either use mesh wire or quarry dust to bury the conduit pipes.
When you are installing switch boxes, and distribution boxes, You should leave a 2cm allowance protruding for the plaster works. This practice ensures that your boxes are flush with the walls after plaster works are done. If you ignore this, you may find that your boxes are deep inside the walls. This makes it difficult for you to install your switches and sockets outlets.
You can ask why is it difficult to install the switches and socket outlets? The answer is simple standard screws that come with switches and sockets they are not very long. In this case, you have to purchase extension screws to mount the socket outlets whose mounting boxes are deep in the walls.
Concealed wiring in the ceiling.
Well concealed wiring in the ceiling is quite simple in that you don’t have to chisel the walls. Mostly the ceiling is open.
Now in the ceiling, there are three situations that you can encounter when doing concealed wiring. These situations are
- Open ceiling.
- Ceiling with concrete wall
- Celing with concrete wall but you have to pass your conduits in the slab electrical decking.
An open ceiling is one that is not under a concrete roof. when you are doing concealed wiring on an open ceiling, the materials that you use will depend on the type of traces that are used.
Mostly it is the lighting circuits that take major works in the ceiling. Here the first thing to consider is the number of lighting points that you are going to have in each room.
After knowing the number of lights in each room, you can proceed to construct your conduit pipes. In lighting circuits, you use loop inboxes and junction boxes. I must mention that you place a looping box at every point where you will install a light fitting.
When wood or plunk traces is used, you fasten your conduit pipes using saddles and ceiling nails. If you are using 20mm conduit pipes, you use 20mm saddles to fasten the conduit pipes. In short, you use saddles that are compatible with the size of conduit pipes that you are using.
When ripped channels or metal traces, is used, you fix the conduit pipes with cable ties.
Celing with concrete walls.
In this situation, you will use everything that you use when to fasten conduit pipes to wooden traces except that you are not going to use ceiling nails. You use a drilling matching to drill through the concrete wall.
Then you put fisher plugs in the drilled holes. The fisher plugs come with a screw that you use to fix the conduit pipes to concrete walls of the ceiling. Don’t forget saddles are used as well.
Celing with concrete but you have to put conduits in the slab.
Lay conduit pipes in the slab are one way of doing concealed wiring. In order for this method to be effective, you should be able to read electrical schematic drawings or you have a basic understanding of electrical and electronics circuit symbols.
You start by marking all the lighting points on the deck. After that you start putting the looping boxes in all the marked points, Then you start interconnecting all the boxes and looping boxes to make a complete circuit.
I must mention that in-slab electrical decking is a must to make ring circuits both for the electrical tubing and electrical wiring. This ensures that should anyway be blocked when pouring concrete on the deck, you will have another way through which you can route your cables.
PVC pipes for concealed wiring.
PVC conduit pipes play a very big role in concealed wiring.When you want to use PVC conduit pipes,you must ensure that you use high quality pipes especially when you are doing slab electrical decking.
What are the qualities that you should look for in high quality conduit pipes?
- The PVC pipe,should no easily break when under pressure or when stepped on.
- .You should bend the pipe with a pipe spring bender.
- It must be made in a standard size like 20mm , 25mm and 32mm.Depending n the task that you want to perform.
- You should be able to make bends and offsets without any difficulties.
Advantages and disadvantages of concealed wiring.
In every thing that a man does,no matter how good that thing is it will have some short coming.Therefore I am going to highlight both the advantages and disadvantages associated with Electrical concealed wiring.
Advantages of concealed wiring.
- concealed wiring has a long life span.
- This is the safest wiring system.
- No risk of electrical shock.
- waterproof wiring system
- durable and very popular system.
- It is not easily affected by corrosion
- The conductor are protected from moisture.
- This wiring system is neat makes the walls to be clear,it leave room for decorations.
- It is attractive and appealing.
- Conduits provides protection against mechanical damage and electric shock.
- It is a reliable and popular wiring system.
- Renovation works can easily be performed .When you want to remove damaged cables, You can easily pull them out.
- Do not hamper interior layout as conduits are concealed in the wall.
- It can be used in humid areas, areas where chemicals are manufactured and smokey area.
- It is a long-lasting wiring system.
Disadvantages of concealed wiring .
- This is in an expensive system compared to other systems.
- The extra earthing conductor is required when PVC conduit is used.
- It is difficulty to find faults in the wiring.
- It needs additional conduit pipes when you want to make extensions or alterations to the building.
- Alterations are difficult to make.
- Concealed Wiring installation is difficult compared to other methods.
- Changing the location of appliances or switches is difficult.
- The fault-finding process is difficult.
- Requires proper planing when you want to do additional connections in future.
What is the conclusion of the matter?
I think that electrical concealed wiring is the best way to wire a building ,for a permanent structure.Many are the times when you need to do temporal works .You can use surface wiring and other methods of wiring.
If you want to wire a house for the long term,engage a qualified electrician to help you.That is if you are not in the electrical field.
For experienced Technicians and Electricians,what is your experience in doing electrical concealed wiring?How do you do it?Share with me in the comments section below.