Before central air and heat, wool regulated air temperatures in homes and offices, in winter and summer.
Wool carpet, being a natural fiber, wears differently and installs differently than other fiber carpets. There are four different types of construction, generally speaking. One is tufted wool, which consists of wool fiber being tufted into a primary backing, with a secondary backing added to that for stability. The second type is a woven velvet. The term velvet refers to the construction of the components, rather than a smooth surface, which is what comes to mind for most people. The third is a Wilton. Wilton is generally manufactured with a five frame construction, making it a more durable carpet. The forth type is Axminster.
Some people in the industry have a misconception that these products can be installed the same way. The three different ways of installation that are most used are: stretch-in installation, direct glue-down installation, and double-stick installation. Not only are they installed differently, there is different equipment used for each installation. BUT every one of these products, when using the stretch-in method, should always be power stretched, using a power stretcher.
The direct glue method uses different trowel notch sizes and different rollers.
For example, if you are direct gluing a tufted product or woven product, you would use a trowel size of 1/8”x1/8”x1/8” U notch. The roller that would be used would weigh no more and no less than 75 lbs. For all these products on double-stick installation with a rough back carpet, i.e. some Velvets and Axminsters, you would use a 1/16”x1/16”x1/16” Square notch trowel for pad to floor. For carpet to pad, you would use 1/8”x3/16”x1/8” U notch trowel. For smooth back carpets, you would use 1/8”x1/16”x1/8” U notch trowel. For all double-stick installations, the roller should be no more than 35 to 50 lbs. The carpet should be rolled in both directions, and then, in 3 to 4 hours, it should be rolled again, in both directions. The glue that should be used for pad to floor should be a pressure sensitive glue. Glue for carpet to pad (or even a direct glue) for these products should be a high solids multipurpose glue, about 67% solids.
With all types of carpet installation, carpet should be allowed to acclimate for a minimum of 24 to 48 hours. Atmospheric conditions play a big part in all areas of installation. On glue-down or double-stick installation, there should be no vacuuming for 72 hours; otherwise, it may cause the bond to be broken because the glue has not yet cured. (Do not use a vacuum with a beater bar because this will cause fuzzing.)
There should be no moving of furniture on rollers for 72 hours after installation. If time constraints keep that from happening, then plywood should be laid on top of the carpet to distribute the weight.