Attic Insulation

The Big Cover-Up


A Service Detectives Top Tip Special

25% of the heat loss in your home comes from your attic. Because of this, it makes perfect sense to ensure that your attic has adequate insulation. What most people never consider though is the dangers of blindly insulating. With most insulation blown in by companies that have little or no electrical background, could their lack of knowledge put you and your family at risk? This first in our 2020 Top Tip Series will reveal the information you need to ensure that your attic insulation project doesn’t lead to devastating consequences.



Types of Insulation

From foam spray cans to loose-fill cellulose and fiberglass, to insulation batts, vapor barriers, foam board and long-run rolls, there is no shortage of the types of insulation available. While there are dedicated companies who specialize solely in insulation, the majority of insulation seen in Southern Illinois is installed by heating and cooling companies, including Service Detectives.

Step 1!


Regardless of which company you choose, or which insulation type(s) you go with, the very first step that must be completed is a full inspection of the area to be insulated. Unfortunately, this is the step that many companies fail to complete adequately.

Our service experts complete dozens of home rewires per year, and all too many begin with calls from concerned customers whose home is undergoing insulation work that hasn’t been inspected correctly beforehand. Not only does this increase the time involved, forcing the insulation installer to stop work temporarily, but can often require removing what insulation has already been laid to correct critical issues.

This isn’t to say that companies undertake this work deliberately, ignoring potential hazards, but it is almost universally a lack of electrical knowledge on the part of the installer. Heating and cooling companies that do not offer electrical services as well, often have only the most basic understanding of electrical systems, the national and state code, and the common hazards in wiring.


So What Do They Look For?


There are several common hazards to homes in Southern Illinois:


Knob & Tube Wiring

Dangers of Knob and Tube

Knob and tube is something that we’ve written about extensively in our Survival Guide Series. Knob and tube was a common standard between the 1880s and 1940s and continued to be used into the 1970s. Knob and tube has no ground wire and the fabric sheathe covering the live wires becomes brittle and damaged over time, as do the ceramic and iron knobs and tubes around which the wires wrap. Exposing the live wires to the air will not in itself cause a fire or surge, but spraying or laying flammable insulation on top of these exposed wires is a recipe for disaster.


Braided Two-Wire Romex

Braided Romex IssuesAs knob and tube began to fall out of favor, and as early as 1906, braided two-wire romex became more and more common. Still lacking a ground, but without the ceramic knobs and tubes, the copper live wires were instead insulated with rubber and wrapped in a braided cotton sheathe. These sheathes were sometimes dipped in tar to retard moisture, where others used a wax paper to separate the wires and cover the rubber insulation. The dangers, aside from the lack of ground wire are similar to knob and tube, in that both the rubber insulation and the braided wrap become brittle over years of exposure to all temperatures in poorly insulated spaces.


Open Splices

Open Splices In An Attic
here you can see that these splices have been left open with tape holding the wires together. Heated wires will melt the tape and cause fires.

A splice is any connection made between two different wires to complete a circuit. All splices should be made with a wire cap (a colored thimble-shaped object that twists the wires together and secures them). An open splice occurs when that connection is left exposed to the world, and not contained within a junction box. Standard electrical codes require that all splices be contained within a plastic or non-conducting metal junction box. This significantly limits the chances of a splice coming loose by adding a layer of protection against the wires being pulled apart.

Junction boxes also prevent wires that have come loose from sparking into insulation, wood, or any other flammable material, or from overheat and melting caused by surges.  Many inexperienced DIY’ers and poor quality “professional” electricians leave splices open in attics, crawlspaces, and wall spaces because they don’t believe anyone will ever notice them. This corner-cutting tactic is commonly used by less scrupulous contractors to save time and money on their end at the expense of the customer and their family’s safety.


What Can I Do?


Here at Service Detectives, our service experts are committed to ensuring that every one of our Southern Illinois families has all the information they need to make informed decisions about their family’s health, safety, and comfort. When we complete an electrical evaluation or a whole-home inspection, we encourage homeowners to come with us and see what we are seeing.

When you have any service company come to work on your home, you should insist on being given all the available information. Before beginning any insulation work, you should ensure that you are satisfied that your chosen contractor completes a full evaluation of the area to be insulated. In the case of an attic, it’s essential that you specifically ask about knob and tube, two-wire romex, and open splices. This gives the contractor a heads up that you know what you’re talking about and that they should take you seriously.


As always, if there is ever a shred of doubt in your mind, give our friendly office team a call or text at 618.993.4357, or reach out to us through our online booking or contact form and we’ll have one of our highly trained service experts complete our comprehensive whole-home inspection for just $200.

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