You may think that YouTube is an oasis of helpful home improvement videos. After all, anyone with a smartphone can upload a video in seconds. Each week I scour YouTube for videos I feel may help you save time and money. With each passing day, I’m convinced that YouTube is a cesspool of bad advice. For every decent video that contains good information, I see 20 or 30 that are created by fools.

Allow me to share a few examples. There are a disturbing number of videos showing an easy way to create concrete walkways, sidewalks and door stoops. The uninformed folks on the video buy bags of dry concrete mix from a local hardware store, lumber yard or big-box store.

They pour this dry concrete mix into forms and drag a board across the forms to make the top surface smooth. They make fancy imprints or designs in the dry powder. They then lightly mist the surface of the powder to start the chemical hydration reaction. This reaction causes microscopic crystals to form that act like Velcro. These crystals, when allowed to completely coat each individual piece of sand and stone, are the glue that holds the aggregate in concrete.

After an hour or so, the uninformed video hosts start to flood the top surface with water. It begins to soak into the dry powder just below the surface. My guess is the video hosts never took a geology course. The heavy water grabs onto the ultra-fine cement powder and starts to transport it down into the mix.

Have you ever seen what happens in a rainstorm that falls on dry dusty soil? The heavy rainwater captures the ultra-fine silt and begins to move it down and through the soil. This is why creek water turns muddy just after the storm. Go to the creek hours after the storm and the water is magically clear.

Think about it. How do you know if you’ve added enough water to the concrete mix? How do you know if you added too much? How strong is the concrete just under the surface where most or all of the cement powder has been carried away by the water?

I’m currently working with the Portland Cement Association and its scientists to prove that this method of pouring concrete is perhaps the worst way to do it. Mixing concrete the traditional way, with the proper amount of water, coats the sand and stone with the cement paste. This is the best way to pour concrete, hands down.

Perhaps the worst videos are those I see that tell you how to create thicker wood-framed walls when building a home or room addition. Many pooh-pooh 2-by-6-inch walls and urge you to build two separate 2-by-4-inch walls separated by an inch or so. These super-insulated walls are supposed to save you big money on your heating bills. Not one of the videos I have watched bothers to do the math for you.

If you follow the advice in these videos without doing the math, you’ll be in for a huge surprise. It’s all about payback. Whenever you spend money on something that claims will lower your utility bills, you must determine how many months or years it will take to claw back in fuel-cost savings the extra cost you spent up front on the improvement. Only after you get back all this money do you then start to finally save money.

I decided to do the math on this double-wall method of construction. My imaginary two-story house was 50 feet wide and 26 feet deep. It had standard 8-foot ceilings on both floors.

My calculations showed you would need 228 extra 2-by-4 studs, 40 2-by-4-by-16s for the top and bottom plates for the extra walls, clear pine for the window and door extension jambs, and 50 rolls of 6-inch fiberglass. The total cost of these materials in 2024 here in New Hampshire with no sales tax was $6,125.

It’s safe to say the extra labor, overhead and profit to install all of these things might be around $10,000. The total upcharge for the super-insulated exterior walls would be about $16,000.

Look online and you’ll discover that the 2023 average heating cost in the USA for homeowners was the following: $931 for natural gas, $2,354 for heating oil and $1,359 for electricity.

The heat loss through the windows, doors, attic and floor will be the same. You’ll only reduce your heat loss through the walls. A 20% savings projection would be generous. This means you might save $186 a year if you heat with natural gas, $420 if you heat with oil and $271 if you heat with electricity. If you use air conditioning, you’ll save maybe an extra $150 each year.

It’s your turn to do the rest of the math. Tell me how many years it would take you to break even. If you heat with natural gas, it would only take you 86 years.

The break-even calculation is much more complex because of interest and investment income you could have achieved had you not spent the money.

The bottom line is: Beware of what you see on YouTube.