Just like a steel trowel, only use a fresno after the surface has been floated with a wood or magnesium float. In fact, most manufacturers refer to a fresno as a fresno trowel. A fresno is a steel trowel and should be used just like a hand-held steel trowel. Handles are attached to the blade with adjustable or swivel brackets. Blades are typically 5 inches wide and 18 to 48 inches long with rounded corners, but square corners are available. FresnosĪ fresno is a large, long-handled trowel that looks similar to a bull float, except the blade is made of tempered or “blue” steel.
Increasing the blade pressure compacts and densifies the surface mortar to create a smooth, hard, and more wear-resistant surface. Also, progressively increase the tilt angle of the trowel blade to increase blade pressure. Keep the trowel blade as flat as possible.Īs the surface becomes harder, perform subsequent trowelings with smaller trowels (in width and length). Use large sizes for the first troweling to spread the blade pressure over a large area, which minimizes the risk of prematurely sealing the surface. Hand finishing trowels should be made of steel, usually 3 to 5 inches wide and 10 to 20 inches long. Troweling makes the surface hard and dense. Troweling is done in the final stages of finishing and only after the surface has been floated. Use a steel or fresno trowel, depending on the desired surface hardness. Use a wood or magnesium float and don’t seal the surface.Ĩ. Float to embed the coarse aggregate particles, remove surface imperfections, and create a smooth surface. Joint (tooled) to control random slab cracking.ħ. Edge along form edges to densify and compact the concrete, which minimizes edge chipping.Ħ. Wait for the concrete to stiffen and for bleedwater to escape and disappear.ĥ. Bull float to remove ridges and fill voids left by the screeding operations, and to slightly embed the large aggregate particles before bleedwater collects on the surface.Ĥ. Screed or strikeoff the concrete to the proper elevation.ģ. Too much pressure can seal the surface by compacting and densifying the mortar along the surface. Increasing the blade angle will reduce the contact area between the blade and concrete, which increases the blade pressure. To avoid blisters and delaminations, the surface must be kept “open” so bleedwater and entrapped air can escape.
#Concrete float full
Keep the blade as flat as possible or in full contact with the surface of the concrete to avoid densifying and sealing the surface. While floating with either a wood or magnesium float, do not tilt the float. Trapping bleedwater beneath the top surface, or finishing bleedwater into the surface, can cause delaminations or dusting. Start floating after the bleedwater sheen has disappeared and a finisher using kneeboards has left no more than about a 1/8-inch indentation. Floating also cuts down high spots and fills holes as well as reestablishes the moisture in the surface mortar that was lost to evaporation.Īlways float the surface before finishing with a trowel or fresno. The purpose of floating with an actual float is to embed the coarse aggregate particles, remove surface imperfections such as ridges from bull floating, create a smooth surface, and bring some mortar to the surface. Air-entrainment significantly increases the risk of trapping escaping air bubbles below the top surface, which leads to blisters and delaminations.)īoth float types are available with surfaces 3 to 4 inches wide and 12 to 20 inches long. (Always use non-air-entrained concrete for troweled floors. Wood floats are rougher and typically limited to floating non-air-entrained and high-slump concretes. This is because magnesium floats are extremely durable and easily slide across the surface. While hand floats are primarily available in wood and magnesium, the most popular are made of magnesium. Improper or out-of-sequence use can cause surface defects, including blistering and delaminations. What are the differences and purposes of a magnesium float, trowel, and fresno? Does it really make a difference how or when these tools are used?ĪNSWER: A hand-held magnesium float, steel trowel, and fresno are different tools and should be used in the proper sequence when finishing a hard-troweled floor. Others claim the surface should first be floated with a magnesium float before troweling or using a fresno. Some of my finishers use a fresno instead of a magnesium float to smooth the surface, saying that a fresno is faster and better. QUESTION: Please settle an argument that several finishers on my crew have about hand tools and finishing hard-troweled floors.
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