How to Insulate External Walls (and Decrease Utility Bills)

3 Hours
Learning how to insulate external walls can save you a boat load of money. And make your home more comfortable.
There are a ton of insulation options out there but Roxul insulation was my choice for our master bathroom remodel. I'll explain why.
It's made of Basalt rock and recycled slag. If you don't know, slag is a by-product of steel production. I live in Pittsburgh, so it's kinda second nature to know about slag. Little side note: I was a geology major in college for about 1 year...then switched to chemistry. So I geek out on cool things that make your home a better place to live. Today you'll see why I chose Roxul for our wonky 100 year old bathroom remodel.
Why is mineral wool so awesome? Reason one: Roxul won't catch on fire until about 2000F. I don't know about you, I want a chance to run if my house catches fire. Reason two: Roxul is inorganic and therefore not a food source for mold. Mold in a house is BAD, unless it's in the form of blue cheese. Reason three: it's water repellent. If Roxul gets damp it won't lose it's R-rating, meaning it won't lose it's ability to insulate. Cool stuff.
Here are the supplies you need to install Roxul
Roxul ComfortBatt
Utility Knife
Drywall Knife
Long Sleeve Shirt (insulation is itchy!!)
Goggles or Safety Glasses
Measuring Tape
Plan your project and buy more insulation than you need. Return extra unopened bags.
Start at Top of Stud Bay
Inspect Roxul for Gaps
Inspect for Gaps Along Framing
Cut Roxul with Drywall Knife and T-Square
Make Room for Electrical Lines and Pipes
Inspect Irregular Framing
Cut Roxul for Irregular Framing
Insulate Around Windows
Test for Fire Resistance
Watch my step-by-step video tutorial to see all the tips in action.
Frequently asked questions
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