There is a technique to properly laying pavers to ensure that they are laid to function properly as an interlocking system. This article is specific to the laying process, but not the other processes included in excavation to final product. If you want more information on these other processes, check out our guide to installing interlock.
After you screed your bedding layer, you are ready to begin laying your pavers. The biggest tip while you are planning your screed layer is to only screed what you can lay in that day. This is because it could be stepped on over night by people, kids, or pets which will cause you to need to re-level the affected areas or to re-screed. Also, for driveways specifically it is beneficial to begin laying at the bottom of the slope because they typically have a steeper slope to them and laying from the bottom up works better with gravity and keeping your pavers tight.
When laying your pavers, you do not want to place the paver straight down. This is because that action could cause some bedding layer to prevent the paver to lay tightly to the already laid pavers. If you lay straight down, you may need to move that paver closer to the already laid pavers which will pinch some bedding layer between the joints and cause separation between the two units.
Instead what you want to do is use the click-drop method. You will “click” the bottom half of the paver you are laying against the already laid pavers and drop that paver down following the paver-to-paver friction. This click-drop method prevents any bedding material from separating any pavers.
When laying pavers, you want to be careful with the joints lining up on continuous runs or four corners of pavers meeting. This mostly applies to random laying patterns. You do not want to lay any longer than three feet in continuous joint lines before breaking it up with a paver and you want to avoid four corners at all costs as it is a weak point in that paving system. This is why the herringbone pattern provides the greatest interlock and is recommended for driveways because of the lack of continuous joint lines and no four corners in the pattern itself.
The better you can plan for product to be dropped on your site, the more efficient you will be in laying that material. Knowing what equipment your supplier uses to deliver the product and what the dimensions are of that equipment, you can have them get that material as close as possible to your laying area. Also knowing what product is laid first and in what order it will be laid will allow you to have it all arranged appropriately.
If you have the equipment to move that product around, it is even better for being able to move product from pallet to pavement as fast as possible. If you are going to drive on the already laid material, you will want to protect it with mats and drive straight in and straight out without turning your machine. The pavers do not have complete interlock without the jointing compound installed, so any force applied to them will ruin the project.
When you are laying larger projects with multiple bundles of product, you will want to pull from more than one bundle at a time. This ensures the proper blending of the colors from those bundles. Manufacturers create batches of product with the same amount of color pigment in them, but there may be slight differences from one batch to another. By mixing multiples bundles of product while you lay, you are helping to make those slight variations as unnoticeable as possible and creating a much nicer blend.
Sometimes pavers can have efflorescence issues. This is a white residue that is a natural byproduct of concrete. In small quantities, this can be easily cleaned from the surface of these pavers. However, in larger amounts you will want to raise concern to your supplier or manufacturer rep. If layer after layer or bundle after bundle you are seeing significant efflorescence build up, there is likely a quality issue that needs to be discussed prior to laying the product. The same goes for other quality issues with pavers including pockets on the surface of product, degrading product, broken corners or sides that were evidently run into by a forklift, or multiple broken slabs from transportation. Some pavers come separated with plastic mesh to prevent scuffing, but sometimes this mesh is not included in some layers because the supplier had the product re-stacked. This is typically because the product was returned as excess from one job and condensed with other product in the yard. Sometimes the mesh gets overlooked by the person re-stacking the product and you are left with the scuffed pavers as a result. All of these are quality issues that you should raise to your supplier and manufacturer prior to laying. You should also keep for your record the stickers from the bundles that list the product and batch numbers.
String Lines with Paving
String lines are used to represent top of paver. They should be tied perpendicular to the foundation or structure that you are laying off of unless you are laying at a 45 degree. This requires you to set up a square to the foundation which is where a collapsible square can come in handy. The larger the square, the more accurate you can lay off of it or to set up a string line off of the square.
Alternatively, you can tie a string line square by driving four stakes into the ground that are of equal distance from one stake to the next essentially making a square shape with them. The next step is to measure the diagonal distances from one point to the other. If these two diagonal distances are equal, you then have a true square. You may need to adjust your stakes slightly in order to achieve that, but there will be one stake that you will not want to move which is where you will begin laying from. The other three can be adjusted as needed until those two diagonal measurements are equal. This can also help you to lay at a 45 degree by then tying a diagonal line from stake to stake and laying from that line.
You can also create a square with the 3-4-5 triangle method. This is where any triangle with the ratio 3:4:5 will create a right angle triangle. This requires three stakes with the first stake not moving and representing where you want square or a 90 degree. You can then measure three feet out parallel to the foundation or structure and four feet out perpendicular from the initial stake. The final string line is the angled line to complete the triangle which should measure five feet. Those two stakes can be rearranged slightly to ensure the measurements match the 3-4-5 triangle. This can relate to any triangle with the ratio 3:4:5 including 6-8-10 and so on. When tying your strings, you will want the string line to land on the inside of the stake rather than the outside otherwise the stake will be in the way of laying the initial paver. Laying further string lines to follow when paving should be parallel to your square string lines by measuring off of each far ends to ensure the measurements are the same. Alternatively, you can snap chalk lines into the bedding layer to follow off of.
You can then start laying from one corner of the project and expanding outwards. If you are laying a square / rectangular patio, it may be beneficial to let the client know that you will lay to a full paver which may fall a couple inches in or out of the estimated project measurement. This helps avoid cutting which will prevent slivers or the possibility of the cut pieces cracking under load and it will look aesthetically much better.
No foundation is essentially perfectly square. We have laid against wavy foundations and it has been a pain, but the best thing to do is to communicate this to your client prior to beginning the project. If you prefer to lay square to the foundation that is out of square, you can fill in the gap if it is less than 3/8″ with the jointing compound. However if it is more than this you may be better off laying square to the foundation, but having a border paver follow the foundation regardless of whether or not it is square.