To ensure a successful installation, the correct tools need to be used, but just as critical is the technique used, without which a successful installation cannot be expected.
With more than 50 years’ experience in the local and international flooring industry, Denver Coleman, Chairman of Polyflor SA, answers questions posed by installers, architects and readers. In this issue, he discusses the role that quality tools and technique play in ensuring a successful flooring installation.
“As a specifier it is concerning that the installation quality of vinyl floors is sometimes difficult to achieve. Do you have any suggestions as to how we can ensure the fitters do a better quality installation?” David Smith, Durban
Correct and good-quality tools are crucial to a good-quality installation although they alone will not make a good installation.
The correct use, some experience and practice with these tools along with correct instruction are crucial to achieve the flat, level and well-installed sheet floor installation most specifiers are looking for. The floor will therefore remain visually appealing throughout its lifespan as well as be easier to maintain. One of the main areas of contention and snagging is the welding of vinyl sheet.
Important requirements are:
The edges of the sheet being installed need to be straight and, if not, cut straight using a chalk line. Where necessary, the factory edge should be trimmed off to create a neat and strong weld. Specialist tools are available to easily and quickly trim the edge of the sheet.
Then the recommended method by most manufacturers is to overlay and seam scribe the join so as to get the correct tight butt join. The technique of leaving a gap for the welding is absolutely incorrect and was a bad habit taught in past years.
A seam scriber is essential for this to be well done. Free-hand cutting should not be an option as this usually causes the tightness of the butt join to vary in places and thus creates a weak weld.
The join then needs to be grooved and there are several types of groovers available.
The first is the “P”-type groover which is effective and economical. It has replaceable blades which should be changed on a regular basis. Blunt blades give an erratic and poor-quality groove. Secondly, there are electric groovers, which are really worth using for large hospital-type installations. Once set correctly, ensuring the groove is not too wide or deep and only 2/3rds through the sheeting, a perfect groove is achieved. What should not be used is a triangular-shaped scraper as it grooves too wide and often creates an erratic groove that will go right down to the concrete, creating a weak weld.
Trimming of the weld should always be done correctly and according to manufacturer’s instructions; this means it should always be cut twice.
If a spatula is used it should be correctly sharpened, maintaining the same curve as it had when new. The weld should be cut once with a cutting slide under the spatula knife blade and a second time with the blade flush with the floor surface.
Better options are tools like the Mozart hand trimmer with the attached spacer for the first cut, which swings away for the final cut. A speed version of this is also available for large installations.
Another critical factor that needs to be taken into consideration is the correct application of adhesive.
A new trowel blade should be used with each drum of adhesive. Good-quality trowels are available with fine notches and replaceable blades. Trowel blades should never be renotched by hand and definitely not with a hacksaw or ceramic saw blade.
After the flooring is applied into the adhesive, most installations should be rolled using a clean smooth 68kg three-division roller to effect transfer of adhesive to the underside of the flooring.
Good-quality, straight and hook knives should be used appropriately for cutting and trimming and should always have new sharp blades. Again, they should not be re-sharpened by the installer!
All tools should be clean and correctly maintained and, where necessary, replaced at regular intervals.
Basic tools required are stainless steel straight edges (not pieces of floor trims), pencils, chalk line (with correct chalk and not oxide) and a set of knee guards (which will make the installer more comfortable and create the environment for a better-quality installation).