Linoleum: To Know It Is to Love It
January 12, 2010
Even with business having been pretty slow in 2009, “sustainable” floor covering products are still selling. This is true especially on the commercial side of the industry but more and more homeowners are asking for “green” products as well.
Mention “green” resilient flooring and linoleum comes to mind immediately - and I mean real, natural linoleum, not sheet vinyl that so many people incorrectly call linoleum. Misuse of the word “linoleum” is a pet peeve of mine. Sheet vinyl and any material that is installed in sheet form, continues to be incorrectly called “linoleum” or “lino” and even some tile products are called “Linoleum tile.” This terminology mistake doesn’t bother me so much when laypeople use it but people in our own industry should know better. How many advertisements, or signs on stores, lettering on vans, or just general conversations use the word “linoleum” when in fact they mean sheet vinyl? I would bet that in many cases, you could walk into those stores and they would not have the real thing available.
What’s the difference? There is no vinyl in linoleum. Sheet vinyl is a completely different material. I’ll never forget the smell of my each of grandfather’s stores when I was young – they were full of rolls of linoleum and there is no aroma like it. I still can be found sneaking a whiff of a linoleum chain set in architects’ libraries, and the memories of grandpa’s store came back.
Natural linoleum has been accepted and widely used as a resilient flooring option in “green” buildings because it is an “all natural” product made from up to 75% rapidly renewable materials. It’s a 100-year-old product that s based on linseed oil, which is where the “lin” in “linoleum” came from.
In my March, 2005 column Linoleum: Call it Right, Install it Right, I pointed out some of the key points about working with linoleum, and there have been a few changes since then, so be sure to spend time with the manufacturer’s instructions and don’t assume it’s business as usual with regard to the installation of linoleum. For example, some products now have high performance coatings applied to the surface to minimize staining or damage during installation and make for easier maintenance during the life of the floor. Other products are being manufactured with an added layer of cork blend, which greatly reduces the effects of impact noise and greater thermal insulation and underfoot comfort.
Here is a brief review of installation procedures and some advice for where to learn more. Like any resilient flooring, acclimation is important with linoleum floors. Manufacturers recommend that the flooring and adhesives must be site conditioned at room temperature for 48 hours prior to, during, and after installation. Room temperature must be maintained with Heating/Ventilation/Air Conditions (HVAC ) operating before during and after installation – the usual recommendation is between 65° and 85°F (18° and 29°C) This can be a tough requirement to achieve when you are dealing with new construction but stick to your guns and demand that the site be ready. The products and adhesive don’t act the same way when used in very warm or very cold conditions so there is an increased chance of flooring failure if temperature guidelines are not followed.
In a number of my previous columns I have covered moisture testing and substrate preparation at length, so I will not repeat myself here. Be sure you are in compliance with ASTM F 710, Standard Guide for Preparing Concrete Floors to Receive Resilient Flooring and do not install the floor if you are not within the recommended moisture and pH ranges.
Proper handling and storage is important to prevent dealing with distorted material at the time of installation. Keep sheet linoleum stored standing on end with material rolled face out on a sturdy core until time of installation and make sure tile products are stored flat and neatly stacked to avoid the possibility of material distortion. On large jobs, install rolls in sequential order and do not reverse sheets - everything is installed in the same direction. As cuts are made off the rolls, they should be numbered so everything is installed in sequence. Cut only the number of lengths/sheets off the factory rolls that can be installed on the same day and allow approximately 3” (76.2 mm) excess on each cut for trimming.
Adhesives for linoleum have changed over the years – we have come a long way from the brown linoleum paste that was used in the old days. Specialized acrylic adhesives have been developed for linoleum and for application in areas subject to high point loads, topical moisture, or temperature extremes; two-part polyurethanes are being used. Before pricing out a job, estimators need to clarify which adhesive is appropriate for the job. I regularly recommend to architects that they write the adhesive into the specification but that may or may not be the case so ask questions before you get started.
Stove bar marks are a unique characteristic of linoleum that may or may not be present on the material you are working with. Some manufacturers have changed their manufacturing process to eliminate them. However, it’s something to be aware of so you know how to handle it if you run into it. What is a stove bar mark? When curing linoleum, the product is suspended in large loops in the “drying rooms.” The top of each loop, known as a pole mark is cut off and recycled. The bottom of each loop is called a “stove bar mark” and will appear approximately in the center of each roll. When installing material with a stove bar mark, simply spread adhesive on the back of the material with the flat side of the trowel before spreading adhesive on the floor. This is sometimes called “buttering the back.” After that, spread the adhesive on the floor normally. You must get the material into the adhesive while it is still wet. When you place the stove bar mark into the wet adhesive, massage the material down and push it flat. Roll the material with a 100-lb roller. Roll the stove bar mark first to avoid trapping the tension on the material, then roll the rest of the material - first across the width and then lengthwise. Place weights on the stove bar area until the adhesive sets up.
Seaming linoleum is a different process from other sheet materials. Linoleum tends to grow in width and shrink in length so side seams need to be cut slightly open and cross (end) seams do not. This is different from what we have all learned about seaming other resilient flooring materials where the seams are cut “net.” 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. Because linoleum is stiffer than other materials, it is usually necessary to fit the material by direct scribing or pattern scribing. Install one sheet at a time and trim the seaming edge of the first piece by removing 1/2” of the factory edge using an edge trimmer or straight edge and knife. Position the next sheet so that the sheet overlaps the previous sheet by 1”. Fold back the sheets, apply the adhesive with the recommended trowel and allow proper open time. Allowing the proper open time will help to minimize knee marks, roller marks and trapped air blisters. The amount of open time will vary according to job conditions, temperature, humidity, air flow and type of substrate. After setting material into the adhesive and rolling the floor, recess-scribe the seam to achieve a net fit. Seams are often heat welded so be sure the proper welding rod, router and heat gun tip are used – the tools may not be the same as other sheet products.
For linoleum tile, the same rules hold with regard to substrate preparation, testing and adhesive selection. Lay out the room as you would for any other resilient floor tile and mix tiles from multiple cartons. Linoleum tiles are usually quarter turned but double check the specification or the customer’s preference before you spread the adhesive. Lightly butt tiles together when placing the flooring into the adhesive - do not force tiles together or a ledge condition at the seams and corners will occur. Don’t slide the tiles after setting them into the adhesive - this will force the adhesive out between the seams.
The variety of linoleum colors and design possibilities can really allow installers to be artists. I remember my grandfather telling me how he did a lino job that had an elephant head cut into the center of the floor. Today, there are a lot of similar applications- sometimes cut on the job and sometimes pre-cut by water jet or other methods and delivered ready to install. Borders can be flashed up the wall and logos or other designs can be cut into the floor. There really are a lot of great possibilities.
Finally, one of the most common complaints on a new linoleum floor is that the color does not match the samples. “Drying room yellowing” is a natural phenomenon that occurs during the manufacturing process of all linoleum. As linoleum cures in the drying room, a yellowish cast may develop on the surface due to the oxidation of the linseed oil. This is temporary and disappears after exposure to either natural or artificial light. The time required for the yellow cast to disappear ranges from a few hours to several weeks depending on the type and intensity of the light source – usually more quickly with exposure to natural light. The application of floor finishes will not interfere with the dissipation of the yellow cast ant it will not go away on areas not exposed to light.
Honestly, not all installers can work with linoleum. Those who know it and understand it love working with it. If you use the same techniques as you would with other sheet goods you will be likely to have a failure. I’d recommend that you invest some time in a training seminar or week-long school to learn abut it. All of the manufacturers offer training in linoleum installation and their sales people tend to refer work to flooring contractors or dealers who have trained their installers. This 100-year old product is back and selling as well as it ever has. Installers who understand it and can install it correctly will have added income opportunities.