Many homes built in the early 1950s often featured little in the way of wall insulation. However, when insulation was used, it usually consisted of a product called rock wool or stone (or slag) wool. Still in use today, it's made by melting down rock and sand and then spinning it together to make an insulating fiber. Because it's made mostly of rock, it is fairly resistant to fire as well as to the buildup of mold and fungus.
Spun fibers of rock wool combined together often resemble cotton candy. Known originally as slag wool, it made its first commercial appearance in Germany in 1871. Developers at the time noted that it worked well as a thermal insulating material for structures and also around pipe. Rock is melted to 1600 degrees Fahrenheit, making it molten. It is then put on fast-rotating spinning wheels and bound together using food starch and a little mineral oil.
Finished rock wool fibers pressed into sheets and rolls have a strong ability to take the air passing through them and partition it. It's this partitioning action that helped to make it a useful thermal barrier in '50s-era wall insulation. It also possessed a notable degree of fire resistivity due to the material (rock) it was composed of. For early 1950's home building, it normally came in rolls or sheets, which were then placed between open wall studs.
Besides its thermal insulating and fire resistivity characteristics, rock wool also strongly resists moisture buildup. Additionally, because of its material composition, it doesn't support mold or fungus growth within it. There's no moisture, which means mold or fungus has little chance to begin growing. In the early 1950s, the material was appreciated more for its insulating properties than anything else. Rock wool was also attractive because it's good at absorbing sound, making for a quieter home.
Like almost any fiber product, if you find you have rock wool in your walls, some precautions should be taken if handling it. Though it's made from naturally occurring materials, dust and small fibers emanating from it can be an eye, skin and respiratory tract irritant. They're not carcinogenic, though, unlike other fibers used to insulate pipe or around furnaces, such as asbestos. Just use work gloves and goggles as well as a standard dust mask if you'd like.
- Photo Credit Hemera Technologies/AbleStock.com/Getty Images
Home Insulation History
People have used simple ways to keep their homes hot or cool for thousands of years. Fiberglass insulation is a relatively recent...
Types of Insulation for an Old House
May years ago, home insulation was anything that was plentiful offering any kind of insulating qualities that would keep the cold out...
What Kind of Currency Do They Use in Greece?
In 1981, Greece joined the European Union. One of the goals of the Union was to adopt a universal standard of currency....
Electrical Wire Insulation Types
Electricity can jump from wires to nearby people, metal or other conductors. To prevent this, a nonconductive material must be used to...
How to Replace Wall Studs in a Mobile Home
Mobile home wall studs become damaged or warped over time causing lumps in the wall covering. If the wall bows out too...
How to Kill Mold Under the House
Mold is toxic. It can grow virtually anywhere that is warm and moist. To reduce or eliminate health problems stemming from a...
How to Tell If Fabric Is Wool?
If you've purchased fabric with no fiber content label, or came across an unmarked piece of vintage clothing or material, it is...
How to Make Rigid Foam Insulation Waterproof
Rigid foam insulation products are ideal for surfaces on which you intend to install flooring or wall coverings that need a flat,...
What Is the Cheapest Roofing Material?
Picking out a new roof can be a daunting experience because of the many materials available. For many, the answer is to...
What Kind of Insulation Should I Use in My Attic?
Adding insulation to an attic helps reduce utility bills in the summer cooling and winter heating seasons. In addition, some forms of...
Types of Bubble Wrap
Bubble Wrap was invented in the late 1950s by two men named Alfred W. Fielding and Marc Chavannes. Today, Bubble Wrap is...
Modern Home Styles in the 1950s
Everyone wanted to own a home following World War II, and the American building industry was happy to oblige. During the 50s,...