3 Tips for rewiring an older home

Are you looking at purchasing and renovating older home?

Here are a few thing to consider:

Heritage homes have a lot of character and strong bones, but the wiring methods in the early 1900’s were a lot different than they are today.

From the early 1900’s -1940’s Open wiring or Knob & Tube wiring method was used. This wiring method consisted of single hot & neutral conductors protected by a rubberized cloth fabric running individually through the walls and ceilings. Connections were made at any point along the length of the wire with connections buried behind the lath and plaster.

The major issues with this method is there is no access to the buried connections and there is no ground wire and typically was installed without metal electrical boxes.

In the 1930’s NMD Non-metallic sheathed cable was developed. This cable consisted of a hot and neutral wire in the same cable, protected with a similar rubberized cloth fabric as the knob & tube.

This cable slightly more modernized eliminated a few of the safety concerns, still there is no grounding conductor.

After 1965 the modern form of NMD was introduced. Now the cable consisted of a hot a neutral and a bare grounding conductor. The sheath of the cable now consists of a strong vinyl coating.

Between 1965 & 1974 both copper and aluminum NMD cables were used in residential installations.

Regardless of the wiring methods or cables use the power requirements in home have increased drastically. Not to mention the ever evolving Canadian Electrical Code.

In most cases a complete rewire is necessary, for insurance and safety. While this is a labour intensive task, it’s not impossible and could be worth the cost and effort. Especially if it is the home of your dreams. CodeRad Electrical in Calgary shares some tips for rewiring an older house:

1. First determine the demand load.

Service and panel size. One thing to consider before starting a renovation is to determine whether your current electrical panel and service will be able to handle the load.

Panel size you can typically do a quick visual check to see if there is any unused slots in the electrical panel. However it is best to consult an certified electrician, as some panel manufactures do not make Arc Fault Breakers which are now required for most circuits with a receptacle. The age of the panel is another area to consider typically circuit breakers life span is 30-40 years.

Service sizing is determined by square footage and size of larger electrical loads. If you do your homework on you appliances and have spec sheets ready for you electrician they a can do a quick calculation to determine the required capacity of your service.

*Note most insurance company’s now require a minimum 100Amp electrical service before they will insure.

Learn how to determine electrical circuit load capacity.

2. Check local electric and building codes.

When you hire a professional electrician, they will do this for you. Doing this is absolutely necessary for ANY electrical work you might do in your home.

Permits must be pulled when required. This ensures code compliance and quality of installation.

Remember recently renovated does not mean the electrical installation is safe or up to current electrical codes. While the final product may look nice, it is important to check and make sure that the proper permits we taken out and inspections have been approved.

If you plan to sell your home in the future and there is no permits on file it can be quite costly, you will now be forced to hire a certified electrician to pull a concealed electrical permit. They will now have to bring the installation up to the most current electrical codes, even if the installation was done to code at the time.

3. Always hire a licensed electrician.

Before hiring an electrician, ask for proof of certification. By law it is mandatory that any certified electrician carries their Journeyman or Master Electrician Certification Card on them at all times. It is your right to know you have hired a certified electrical contractor.

When comparing estimates take the time to review the details and ask questions.

At CodeRad Electrical in Calgary we take the time to make our estimates as detailed as possible, so you know exactly what you are paying for.

Electricians in Calgary

CodeRad Electrical Ltd. offers a full spectrum of electrical services for residential and commercial projects. From rewiring a home, electrical repairs to home renovations and home automation systems. They’re dedicated to code quality and customer satisfaction.

If you need an electrician, contact CodeRad Electrical!


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