Living with linoleum
It’s not difficult, it’s just different
Linoleum is a very old material that has made a comeback over the past 20 years or so. I mean the real natural linoleum, not any other kind of sheet resilient. Sometimes the terms get mixed up. As sheet vinyl started to gain in popularity compared to natural linoleum in the 1960s and 1970s, the term linoleum, or “lino,” continued to be used for all sheet goods. However, these are two totally different products.
If you are asked to install linoleum and it turns out to be real natural linoleum, and not the vinyl you have installed a hundred times before, you better be ready because there are some differences between the two products.
Linoleum is defined in ASTM F 141 as a surfacing material comprised of a solidified mixture of linseed oil, pine rosin, fossil or other resins or rosins, or an equivalent oleoresinous binder, ground cork, wood flour, mineral fillers, and pigments, bonded to a fibrous or other suitable backing.
There are product brand names that end in “oleum,” but it’s all the same basic product, old fashioned natural linoleum like my great grandfather used to sell and my grandfather used to install. Invented in England by Frederick Walton in 1864, it was named after its main raw material, linseed oil. Linoleum also is made from cork powder, wood powder, organic pigments, limestone and jute.
It shrinks and grows
Linoleum tends to shrink in length and grow in width. So, your seaming technique on linoleum will be different than other flooring materials where the seams are cut “net.” Cut length seams slightly open to allow for this. Pay attention to this detail and refer to the manufacturer’s guidelines. Specialized tools are available for trimming linoleum, so make sure you are ready by having the right equipment. Seams are sometimes heat welded, but are also left without any kind of sealing in many cases.
Another difference comes from the chemistry of the material, which causes the colour not matching the sample. It may have an amber or yellowish tone. ASTM F 141 defines this as “Drying room yellowing — a yellowish cast on linoleum resultant from the oxidation process that will go away with exposure to light.” This oxidation happens during the curing process, and, depending upon the amount of natural light, it can be gone in a few hours to a few days. It is not a defect or a manufacturing problem.
Stove bar marks are another natural characteristic caused by the way linoleum is made. During the same curing process I mentioned before, the material is hung in the drying room in very long sheets. These sheets are hung over a bar at the top and then at the bottom loops back up. The top loop is cut off and recycled but the bottom of each loop can sometimes show up on a roll of material. This is called a stove bar mark.
To install material in this case, butter the back of the material by using a flat trowel to put a small amount of adhesive on the back of the goods. Then, spread the adhesive on the floor and lay the material as you normally would. When you place the stove bar mark into the wet adhesive, push the material flat and work it on so there is good contact.
Use a 45 kg (100 lb) roller to roll the floor after you set the material into the adhesive, beginning in the area of the stove bar mark, going side to side. Then roll the rest of the material side by side and again going lengthwise. Keep an eye on the stove bar area and use weight to hold the material down if needed until the adhesive dries.
The right glue
Speaking of adhesive, linoleum gets installed into wet adhesive, so adhesive open time is very important — don’t spread too much at once. The type of adhesive is also critical, so use only a product that is made for linoleum. A VCT adhesive won’t work and “multi-purpose” adhesives might not be the way to go, either. Do not use anything other than the recommended adhesive, and make sure the floor is rolled immediately after setting the material into the adhesive.
Be sure the trowel notch is appropriate, or even better, buy a new trowel before starting the job. If you are not sure, conduct a bond test on the job site to be sure you have the proper adhesive transfer. This will help see what kind of working time will be needed based on the porosity of the substrate and the climate conditions on the job. Lack of adhesive transfer to the back of the material is a major cause of installation failures for linoleum. Adjustments to the trowel size and the adhesive open time can be made based on a bond test, so you can be sure you have it all tight.
Linoleum is a beautiful, durable, environmentally friendly product. What scares me is that this amazing product that has been around for generations is so misunderstood. The manufacturers have done a great job of creating training programs, but dealers, installers, and floor care technicians need to make it a priority to create the time for training and education. It’s not difficult, it’s just different.
Christopher Capobianco is a flooring expert currently working with Forest Hill, Md.-based Spartan Surfaces, a distributor of commercial hard-surface flooring. Chris’s family lineage in floorcovering goes back for generations. His career includes time as a retailer, architectural sales rep, technical support manager, consultant, instructor, columnist and active volunteer in several organizations.