What is a Darby in concrete?

A darby is a long, flat tool used to smooth in plastering and rendering. It can also be used on concrete floors. It consists of two handles on a flat plate with slightly lipped edges. A darby is similar to a float, except larger.

Why do you use a magnesium float on concrete?

Although they are slightly weaker than their aluminum counterparts, magnesium floats are lighter and are the most popular choice among professionals. Magnesium smooths the surface of fresh concrete and opens the pores for proper evaporation, all without pulling the surface like a wood or resin tool.

Why is it called a bull float?

Bull Floats

This is because these floats consist of a long handle attached to a wood, resin, aluminum or magnesium float. The handle can measure anywhere from 4 feet to 16 feet long.

When should a bull float or Darby be used in concrete work?

Hand floats, or darbies, range in width from 3 to 5 inches and in length from 12 to 24 inches. Use a bull float for areas too large to reach with a darby, though it may produce a wavier surface. Most floats are available with rounded or square ends.

What can I use instead of a bull float?

Bull Floats and darbies serve the same purpose however, daries are typically use for small areas. Both are used to eliminates high and low spots, and to slightly embed large aggregate particles immediately after strike off. These floats will also work up more paste to the top of the slab to help in finishing later.

Hand Floats

What is the difference between a float and a trowel?

A float has a thicker base than a trowel and is usually made of plastic, sponge, rubber, wood or magnesium – a lightweight pale grey metal. It's used to even up the surface on plaster or concrete, make it firmer and give whatever texture is required. The finish will depend on the float chosen.

How do you use a Darby?

How long after pouring concrete can you float it?

Allow all of the water to disappear before you do anything else. This can take 20 minutes or 4 hours depending on the temperature, humidity and how hard the wind is blowing. After the bleed water is all gone you can get out your steel finishing trowel and put on the final touches.

How do you make concrete smooth after it dries?

What does broom finish concrete mean?

Broom Finish concrete is concrete finished by dragging a horsehair broom, or something similar, over its wet surface. Brushing the concrete makes for a textured surface with small, but noticeable grooves. Broom Finish concrete has been the preferred utilitarian texture for exterior concrete for decades.

What is a Fresno used for?

A fresno is a steel trowel and should be used just like a hand-held steel trowel. In fact, most manufacturers refer to a fresno as a fresno trowel. Just like a steel trowel, only use a fresno after the surface has been floated with a wood or magnesium float.

How many times do you float concrete?

Push the bull float in one direction only across the concrete, keeping its front edge slightly above the surface by raising or lowering the handle. Two or three times is enough. Don't overwork the concrete or you'll weaken it by drawing too much sand and cement to the surface.

What does a Fresno do to concrete?

Purpose: Fresno trowels are designed to attach to long extension handles so finishers don't have to walk out on the slab. They permit rapid work over large areas, such as driveways, but do not achieve the same degree of compaction possible with hand trowels.

How long should concrete cure before removing forms?

The forms or “molding” that holds the concrete in place until it dries should be left alone for at least two days to ensure that the concrete is completely dry. If the forms are removed too soon, the concrete can begin to sag, crack and collapse, especially if conditions like temperature affected its strength.

How long does it take for 4 inches of concrete to cure?

While it only takes around 28 days to cure concrete, drying can take months. The general rule of thumb is that concrete takes about 30 days to dry for every one inch of slab thickness.

How do you make concrete smooth and shiny?

If the concrete floor is sloped, self leveling cement can be applied to make the surface even. Ardex or other similar self leveling cementitous mixes can be applied and poured on to the surface and then ground afterwords just like regular concrete to get a smooth shine.

What is a plasters Darby used for?

The plasters Darby is usually a sturdy pieces of straight aluminium, about 1.5 m long with adjustable handles. It is used to create a level finish between two solid points that would be difficult to level with a hand trowel.

What is a speed skim?

For some Speedskim is a tool for flattening and straightening and for others it is a tool that can also be used for finishing. If you are going to finish with it then I would recommend a pump up spray bottle to wet the surface. That will prevent any juddering.

When should I trowel concrete?

Smooth the surface with a steel trowel after it's partially hardened. Hold the trowel almost flat and swing it in large overlapping arcs while applying pressure. Float the concrete when you're done grooving and edging (Photo 6).

What is the purpose of troweling concrete?

With every concrete pour troweling is important, because it allows the concrete to continue the process of finishing the concrete and squeezing residual water out of the concrete. Removing any excess water out of the concrete decreases the chances of the concrete cracking.

What can I use instead of a trowel?

A hori hori knife is also known as a soil or weeding knife, and is the Japanese equivalent of a garden trowel. It has a serrated blade for cutting roots, and a wider blade than other garden knives for digging soil.