Screeding concrete is one of the first steps in placing and finishing concrete. Screeding is the art of skimming or striking off the surface of the concrete after rough raking it. Screeding when done properly will leave you with a good even flat surface free of humps, bumps holes and low spots. This can usually be accomplished by some DIYers on a small scale, like a sidewalk for example. But i would definitely recommend leaving everything else to the pros, especially if you want the job done right. All too often I have seen people attempt to accomplish screeding concrete jobs that are out of their league and the end product doesn’t turn out.
Screeding concrete is an art form!
Screeding Concrete – Picking The Right Screed
The proper tool for screeding concrete can be as simple as that piece of 2X4 that always seems to be available wherever concrete is being poured, or it can be as extreme as a larger laser screed machine. Picking the right tool for the job will of course depend on the job your performing.
Hand Screeds – Hand screeding is physically the hardest way to screed the concrete, but in the right hands it is the most accurate way to screed. Hand screeds can be a straight wood 2X4. I would not recommend using one more than 12 to 14 feet long. Or a better option would be an aluminum screed. This form of screeding is probably the best option for a DIYer to pour a sidewalk, patio or other small project.
Power Screeds – Power screeding makes the smoothing out process alot easier by leveling out and/or vibrating the wet concrete mixture. They are usually used for larger pours. If quality is important I definitely would not recommend using one unless you have been trained. They do save time and effort but are not always the most accurate screed with experienced operators.
Roller Screeds aka Spin Screeds – Though I don’t have much experience with roller screeds I know that they can be very handy and very accurate. The rollers are available up to 24 feet long with many different attachments available for perfect gutters, curbs and more. The roller screed is a must if you are using pervious concrete. The best thing is the roller screed is so simple to use, even a beginner can turn out decent quality
Truss Screeds – Vibrating truss screeds are one of the most accurate ways of screeding concrete that I’ve used. Truss screeds can have many sections bolted on for reaching across large spans. They are built to ride on forms or rails that are set out prior to pouring.
Laser Screeds – Laser screeds are usually used on larger pours where accuracy is important. This is probably the easiest most accurate form of screeding. A laser screed is operated usually by one guy, a couple of rakers and a laser set up for heights. This specialty screed is not usually something anyone can use, it requires special training to be able to operate it. Alot of times companies who own a laser will rent them out with the operator.
Screeding Concrete – The Process Behind It
Screeding Concrete is done right after the concrete has been poured, rough raked, and edges have been hand floated. The sooner the better, if you leave the concrete too long it will be too hard to work with.
The goal of screeding is to make the surface flat and not leave any holes, humps or bumps. This is accomplished by creating guides to follow while you are screeding, guides can be forms, rails, hand floated edges or wet screeds pulled at the proper height. Each screeding tool follows your guides differently to achieve the flat surface. For the average DIYer it is definitely recommended that you screed an area that you can ride the forms and is smaller than your screed.
When screeding follow your guides and always keep 1/2″ to 1″ of concrete ahead of your screed board to fill all holes and low spots. If you are screeding and leaving lots of voids behind, it is likely you are either not leaving enough mud or you are screeding too fast. If you are screeding and able to ride the forms start at one end and move along in a sawing motion to seal the surface.
Once you have completed striking off any humps or bumps, filling any major holes (minor holes will be filled in with the bull float), ensuring all heights and slopes are correct it is time to bull float the surface.