Graphical Construction Glossary >> Concrete and Concreting. >> Concrete Screed

Concrete Screed

A machine or a hand tool for doing the primary leveling of a freshly poured concrete slab.

Screeds

Forms or made edges set to levels that are used as guides in filling in the area between.

To Screed

To remove excess concrete above the correct level. To bring to the correct level

Hand Concrete Screed

A length of aluminium box section with a handle attached that one man can use to level freshly poured concrete. Or a larger section of aluminium or timber that two men can use to straddle the work.

Power Screed

In it's simplest form an aluminium frame that duplicates the size and action of hand screed, to larger double beam and truss screeds that sit on the formwork either side and spanning the slab being levelled. They have a motorised vibrator mounted on it and drawn from one end of the slab to the other by two men, or by a vehicle mounted winch. They performs the function of an external vibrator and screed.

A concreter using a hand held aluminium concretescreed. It is not hard to imagine the hard physical effort it takes to level a concrete slab doing it this way. When I first started concreting we used to set the forms to the correct height and use a large and quite heavy piece of timber spanning the slab to screed the concrete, using a sideways sawing motion with also a pulling motion.

We would also go back over the roughly screeded area and tamp (use an up and down motion) the surface to help to vibrate the concrete and to also knock down the larger aggregate and to bring up to the surface a slightly higher percentage of fat (fines, cement paste and water)to make the finishing easier.

Fortunately things have changed for the better and we can now get some motorised help to do this labour intensive work. Above is a small one man screed that can be used to quickly screed small jobs. The aluminium extrusions can be changed to suit the work and they range from 1200mm (4ft) to almost 5M (i6ft). This type of screed should be used in conjunction with an immersion vibrator. (Poker).

The double beam screed above is a step up from the previous one. It has to sit on leveled formwork, and the form has to be strong enough to take the vibration. This type of screed can span up to about 8 metres. It has a system that allows it to be pre-tensioned to get a camber just an exact flat surface.

A screed very similar to the one shown here was used to make the panels on my tilt up page and the guys were very happy with it as no other method of vibration was needed and as you can see from the photos of the panels the compaction and finish achieved was excellent.

Known as a truss screed for the obvious reason these machines can handle larger spans and are used in conjunction with winches.

Many thanks to Parchen Construction Supplies for allowing me to use the photos marked "pcs" which are their copyright ©

• Concrete Screed:-Back to top
•  
• BACK:power float
• concrete pump:NEXT

If you didn't find exactly what you are looking for try this search tool that will search the site and the web.

"What can be added to the happiness of a man who is in health, out of debt, and has a clear conscience?
Adam Smith 1723-1790

"When we build, let us think that we build for ever."John Ruskin 1819-1900