Screeding in hardscaping is the act of scraping back a material to create a smooth surface. When pouring concrete, the concrete is scraped back using a long board following a grade to ensure it is smooth. When laying pavers, the bedding layer that the pavers are laid on top of us scraped back also using a long board to ensure that it is smooth to lay the pavers on top of. In each of these scenarios a board is used to be able to scrape back that material. We call this a screed or screed board.
Screeding Tools for Block Paving
When we lay pavers, we need to level or smooth the surface on top of the base material. We do this by adding a one inch bedding layer on top of the base. Pavers are then laid on top of this material, so it is crucial that we get this layer as smooth and accurate as possible. In order to do so, we use one inch outside diameter iron gas pipes that we get from any hardware store as our screed bars (not to be confused with screed boards). They typically come in 10 foot lengths and we cut them to size. These cannot be warped because that will cause our bedding layer to follow that warp. When looking for these, we roll them along a smooth surface at the hardware store to ensure there is no visible warping. We also try to do this regularly and replace them once every year or every other year.
These screed bars are laid on top of the base material and using grade stakes and string line, we set the slope of that patio. Measuring down from this string line that represents the top of the paver surface at the height of our pavers, we set those screed bars at the correct height. We adjust them by using a dead blow hammer and hitting them into the base slightly or build them up slightly using our bedding material. Once two of them are set, we then fill the space between the two with bedding material (concrete sand or High Performance Bedding / 1/4″ angular crushed clean stone) and then scrape back using a screed. We can then repeat this process through our project while also laying that patio on completed areas. Here are further instructions on how to set your string lines and screed.
It is important to note that the distance between one screed bar to another should be the maximum length of screed that you have available to you. A quality screed is incredibly important as any imperfections will show in the surface of your pavement. You can use a long piece of wood, but it is more susceptible to imperfections and will breakdown a lot quicker than buying a quality screed board. The longer the screed board, the more area you can screed in one sitting which will improve your efficiency of having to set your screed bars every time. That being said, it is nice to also have smaller screed boards handy to reach smaller and tighter areas. Screeding a four foot walkway that also has obstacles is inconvenient using an eight foot screed board. Alternatively, screeding a 40 foot wide patio is inconvenient using a four foot screed board.
You can use a long level to screed. Longer levels usually have two handles which makes it convenient to screed with and provides the same results that a screed board would. We sometimes use our eight foot level to level the screed bars with and to screed. This saves the time in having to grab two different tools in having to grab a level and screed board. However, this will put wear and tear on your level. Especially with longer levels that will have more pressure on the ends if you are levelling larger piles of material. This could warp your level over time and it will need to be replaced a lot more often than you would if you did not use it for screeding. Levels are also more expensive than screed boards being at least twice the cost.
6 Foot Screed with Level
These six foot screeds with attached levels are especially great for screeding concrete. As you scrape the concrete back you have a level right in your eyesight to be able to keep track of whether you are level or not. It is especially good when you are levelling by eye and not using references. The screed and level are two separate pieces. The level is a handle attachment that clips onto the screed allowing you to handle this part of the screed while screeding.
For screeding sand or bedding layer material for pavers, this is fine but a little too expensive as the level is not necessarily required. We use a level to level our screed bars while using a screed board to screed the material making this tool a little less useful in our applications. Not to mention it is a little less trustworthy to use a level that is attached separate to the screed board rather than being integrated into the screed board. Any minor imperfection in that level can throw off your screeding and will show on the surface of your pavement or completely mess up your slope.
8 Foot Screed
This is our screed board of choice. An eight foot screed board will allow you to screed the largest area you can while remaining easy to handle. This will make you the most efficient you can be as setting the screed bars can be the most time consuming process of screeding. Additionally, the longer your screed bars the more area you will be able to screed in one screed bar setting. These screed boards at four inches high also make it easy to handle while screeding and allows you to control larger piles that you are screeding.
2 to 6 foot Screed Boards
As previously mentioned, it never hurts to have a variety of screed board lengths in your tools. This 2 foot to 6 foot screed set is nice to have for smaller or tight areas. When you are screeding you may finish your patio with a small two foot area between screed bars and using an eight food screed on this area is not ideal as it will overlap on your existing screeded area. You could also be screeding a long walkway that is just four feet wide with an air conditioner unit in the way or other obstacles and using an eight food screed is inconvenient. This is where having multiple screed boards in your tools is important.
Stand Up Screed
There is one stand up screed available on the market that comes with a variety sizes of screed lengths with the largest being six feet. This is great to keep you off of the ground on your knees when screeding an area. We have bought one and have never used it. The idea is great, but setting up your stand up screed every time by screwing it in and it not having the scraping strength of being on your hands and knees and screeding is not ideal to use. We also always prefer to use our eight foot screed board to be able to do as much area as possible in one setting of our screed bars.