Timing is everything A useful guideline to know when you can start up your trowel, is when the operator can stand on the concrete surface, and leave footprints about 1/8”-1/4” in depth and you can walk on it firmly without the top layer sticking to your boots it is ready to power float.
When should I start power floating?
A rough guide for considering when to begin power floating is when walking on the surface leaves indentations of 3-4 mm. If the concrete is too wet the machine will tear up the surface, and if it is too dry, it will not be possible to trim high spots or fill low spots effectively.
How long do you leave concrete before power floating?
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.
When should you float concrete?
Float the concrete when you’re done grooving and edging (Photo 6). Floating removes the marks left by edging and brings the surface one step closer to a final finish. You may have to bear down on the float if the concrete is starting to harden.
Is it necessary to float concrete?
Floating has to be done on virtually every concrete job after concrete is poured and leveled. When done properly, floating pushes the aggregate down into the concrete and encourages moisture to rise, helping the concrete dry and creating a smoother surface.
What does a power float do?
A power trowel, also known as a power float, is a piece of construction equipment used to apply a smooth finish to concrete slabs.
Is it OK if it rains after pouring concrete?
Rain falling on top of freshly laid concrete can damage the surface and compromise a level and floated finish. Even worse, if too much extra water works its way into the concrete mix, this can result in weak concrete overall.
Can you float concrete the next day?
Wait for the water to completely drain back in before working any further on the slab. If you begin using a float too soon, you could sweep some of the water off the slab before it has a chance to be re-absorbed. Reducing the water content will weaken the surface of the concrete.
Can you finish concrete with a bull float?
A bull float is used to level and smooth freshly poured concrete. Concrete used for visible projects, such as driveways, patios and sidewalks, often requires finishing. A bull float is a tool used for finishing concrete.
Can you over work concrete?
Never overwork or over finish the surface of any exposed concrete slab. This brings too much fine material to the surface, works out the designed air entrainment*, and will weaken the surface of the slab leaving the top of slab more vulnerable to freeze/thaw damage and sheet scaling*.
What does a magnesium float do to concrete?
Once your top is flat from screeding, use a magnesium float to flatten and smooth the top while opening the pores of the fresh concrete, allowing bleed water to evaporate and air to escape. Once the concrete is firm enough and all bleed water has evaporated, use a steel trowel for your final finish.
How thick does concrete need to be to not crack?
To prevent load-stress cracking, make sure a slab is built over a uniformly compacted, well-drained subgrade, and is thick enough to withstand the kind of use it will get. In residential concrete, 4 inches is the minimum thickness for walkways and patios.
Why are freshly poured concrete slabs Bullfloated?
Why are freshly poured concrete slabs bullfloated? For removing excess concrete screeding (strike – off) can be done which involves bringing the concrete surface flush with the top of the form work using screed.
Can you smooth concrete after it dries?
Sand the Surface and Wash the Concrete Finish by fine-tuning with light sandpaper, until the surface is perfectly smooth. We recommend using a hand planer to smooth and compact the surface. If the concrete dries a lot then we recommend that you add water to the surface, this will help you give it a good finish.
Can you power float in the rain?
Using a concrete power float on concrete which not properly set will do negative work and will destroy its finish. In cases when it’s raining light like drizzling or a little short shower, you may continue to power trowel the concrete.
What is a power trowel float pan?
Kraft Tool’s ProForm® float pan is designed to provide even coverage when using non-overlapping “walk behind” and “ride-on” power trowel. The 3/4 In. Slots on the float pan fit to power trowel blades on the machine. The design of the blade slots lets the pan be used on trowels that run either direction.
What is a Kelly float?
The power float or ‘Kelly float’ is equipped with adjustable wide handles to provide optimal control and comfort. Perfect for trowelling off large areas of concrete and slabs to bring out the desired finish.
What is power float finish?
Power float concrete is a concrete finish achieved using a machine designed to smooth, and to some extent level, a newly laid but hardened concrete floor once all bleed water has evaporated; a power float machine uses rotating circular pans to achieve this buffed and polished finish.
What is a float finish in concrete?
A concrete float is a tool used to finish a concrete surface by making it smooth. A float is used after the surface has been made level using a screed. In addition to removing surface imperfections, floating will compact the concrete as preparation for further steps.
When can you helicopter with concrete?
The concrete helicopter must be used before the poured concrete has completely dried. However, if the concrete is too fresh and wet, using the concrete helicopter may cause delamination of the material and concrete will be torn up.
How long does 4 inches of concrete take to cure?
Your concrete should be solid enough to walk on, without leaving footprints, after anything from 24 to 48 hours. By seven days, your concrete should be cured to at least 70 percent of its full strength.
How long should concrete cure before removing forms?
Walls and columns can be removed after about 24-48 hours. Slabs, with their props left under them, can typically be removed after 3-4 days. Soffits, with their props left under them, can be removed after one week.
How long after pouring concrete can you walk on it?
After 24 hours, you can walk on your newly poured concrete, but avoid dragging your feet, ‘doing the twist’, or allowing your pets to walk on it as their claws can scuff the concrete.