If you have a lumpy bumpy brick paver surface, I am sure you are frustrated. I could add fuel to the fire and say you are in this position because was not done right the first time. I could go easy on you and say that our Chicago winters cause everything to move and overtime. In your case, it is possible that both are true. I did not write this article to make you feel good or bad about your current situation. I decided to take the time to write this article because I want to help. In the paragraphs that follow, I will explain how your brick pavers should have been installed and how to repair them now that they have moved. First let us talk about material choices, I will keep this brief because I went into great deal on this topic in our brick driveway article. So you are cursing yourself for having brick pavers because now you have lumps bumps and puddles. Do not be too hard on yourself it could be worse; you could have cracked concrete that needs to be removed, disposed, and replaced, which is more expensive than paver repair. Pat yourself on the back for choosing a material that is serviceable. In our climate everything outdoors (the public road, your sidewalk, your driveway, etc.) moves with the freeze and thaw cycle. The public road has a very deep base with a variety of materials that help fortify it and still potholes arise. Asphalt on a residential setting has the most problems and no good ways to repair it. Concrete on a residential setting oftentimes cracks. Concrete repair options are limited, and very unattractive. If you want more information comparing and contrasting the three pavement options check out our article about brick driveways under the connect tab on this site. Now let us move forward and talk about how your pavers should have been installed in the first place and then I will end this article with what you can do to fix them now that they have moved.
There is more to a quality brick paver surface than what meets the eye. People put a lot of thought into which bricks they want to see on top, but if your pavers have moved it is because not enough effort was put into what went in below grade. Let us start by talking about the subgrade material and then we will get to how it should have been installed and were your first contractor may have strayed.
Stone and Base Installation
There are 3 types of stone that could be used under a paver patio: 3 inch gravel - This stone is 2.5 - 4 inch in size and angular in shape three quarter inch gravel - This stone is three quarter inch in size and angular in shape CA-6 gravel - This is a road mix of three quarter inch stone and finer screenings that lock themselves into place with proper compaction
Three quarter inch stone is used for permeable pavers and we are just talking about standard pavers right now. An industry standard paver installation (in our climate(chicago)) calls for a 6 inch base. To some people this means they dig a 6 inch hole, the problem is with a 2 inch thick brick and a half inch to an inch of sand you are getting 3 - 3.5 inch of stone at best. A better interpretation of the 6 inch base would be if the contractor dug an 8.5 inch hole, installed 5.5 inch of CA-6, and then added half inch of bedding sand before laying the bricks. We at scott flanagan landscape dig a 10 inch hole. We install 8 inch of stone (a mixture of 3 inch stone and CA-6 in) and then limit our sand to half an inch or less.
Now say the proper amount of soil was excavated and disposed (8 plus inches) when your patio was installed. The next question is how well did they install the gravel? The plate compactor that most contractors use is rated to compact no more than 2 inch at a time. Every 2 inch lift should be compacted over 4 times before adding each additional 2 inch of stone. If all 5 inch of stone were added and compacted at once, or they did not go over each lift enough times, fractional settling could be the reason your pavers moved.
We use a very large, expensive compactor that puts down an impressive 8,992 lbft of compaction. Our compactor is rated for up to 5 inch of compaction. However, we still only install the gravel in 2 inch lifts and compact over it 4 plus times per lift.
Once the gravel is at its final elevation, the next step is to level the top surface with bedding sand before laying the bricks. Industry standard allows for up to 1 inch of sand. I have seen many a patio with 2 plus inch of bedding sand. We install less than half inch of bedding sand. What does this all mean and why is it important? The bedding sand is used to create a flat top surface. If the final layer of gravel was not installed with precision and care an inconsistent depth of sand may be needed on the top layer leading to many problems: -Water can run between the pavers and the top level of gravel. The more sand there is the higher the chance that this water movement will cause sand erosion in some spots and sand deposits in other spots leading to paver movement. - If the gravel is not level and there is inconsistency in sand depth this will cause 2 problems: 1) The density of the base will be different and settling will be irregular 2) The amount of water and or ice under your pavers will be inconsistent, which will cause uneven movement when frost occurs as well as erratic settling each time thaw occurs
Buy The Base First, Then The Brick
Customers are always impressed once the bricks are laid, especially if it is an interesting pattern. The more important part of the project to pay attention to is the base. Below is a time-lapse video of a driveway that we installed more than 10 years back. Notice how much time and effort goes into the excavation and compaction of the gravel and how fast the bricks themselves go down. when purchasing a new brick paver installation, asking the right questions is important. Oftentimes you get what you pay for; if the price is lower, there is a very good chance they are putting in less time on the base. This saves them on: labor; disposal of soil, and purchasing of base stone. Contractors that cut corners on the base may save you money in Year One, but that cheap brick paver installation will certainly cost you more in the long run.
How To Fix The Pavers You Have
Now that we know how your pavers should have been installed and some reasons why they may have moved, let us talk about how we are going to fix them: My advice: 1) Call a professional. This is not as easy as it sounds. -- a) This job can be frustrating and time consuming -- b) The average patio takes our 4 man crew 3 days to re do ------- That means it would take 1 profesional 12 days on their own ------- Even if you can do it at the same speed that equals 6 weekends on your own ------- Having your base exposed to the elements that long can lead to other problems ------- Your sub grade should be installed and covered with bricks before rain hits or it will be undermined and you will have problems in the future 2) If you are in the Chicagoland area and you are going to hire a professional, please call us for an estimate on your paver repair project 3) If have reasons you want to do it on your own, continue reading I will give you a detailed how to with a series of what to do and what not to do. Do: 1) Remove all bricks to make way for the proper base repairs needed -- a) without properly repairing the entire base a spot fix will last until the first frost 2) Remove the center field first -- a) these bricks should not be cut so they do not need to go back down in the same spot ----- you will, however; need to first identify the pattern so that you maintain the proper ratio of each size when re installing -- b) do not mix different sizes ----- make separate piles for each size so you can efficiently grab the right bricks when re-setting your field 3) Create a system that works for you to identify and label where the cut pieces were -- a) if not your patio puzzle will never go back down correctly 4) re-lay the cut pieces in your lawn exactly how they were on your patio to keep them organized 5) remove all sand and 2 inches of gravel -- a) Make one pile of sand and another pile of gravel 6) Compact the remaining gravel in place 7) At this point we normally compact 3 inch stone into the base. However, if you are using a standard compactor, you will have to skip this step because a small compactor does not have enough power to compact in 3 inch stone 8) Add the 2 inches of stone you removed back into the base as level as you can to prep for sand -- a) if there was too much sand in the original base you will need to add more gravel and dispose of some sand 9) Use three quarters of an inch of sand or less to get your base completely level so that the bricks will go down completely flat -- a) use as little sand as possible to level your base to limit future movement. Dont: 1) just pull up the pavers that have moved and re set the sand -- a) the whole installation has likely moved. Resetting only a portion of it will only highlight the fractional movement in the rest of the patio that you may not have seen before you lifted what you thought was the problem area -- b) As you learned inconsistent installation of bedding sand causes movement. ----- adding or subtraction a little bit of sand only adds to the the inconsistency of your bedding sand 2) Remove all of the pavers and stack them in a pile -- a) you can move the center field and pile them up -- b) you should save all of the border pavers and cuts for last ----- take photos of them, label them, document their orientation as best you can --------- then choose a space in your yard were you will carefully relocate them in their original orientation --------- --- This will make it easier for you to reset them correctly when the time comes 3) Just level the sand and re install the pavers -- a) you have done the work to pull up the patio put; in the extra effort to examine the gravel
Pro tips: 1) Take lots of pictures before you start -- these pictures will help you remember the pattern -- if you can not figure out the pattern bring the photos into a landscape supply yard they may be better at identifying it and they may have a simplified illustration of it for you to reference 2) add an accent border. A contrasting band will freshen up the appearance of your weathered pavers and in some cases give 20 plus year old pavers an interesting new look
This is not a novice project and it may be best to invest the money in having it done right so you do not have to do it again. If you live in the chicago area and you are looking to hire a pro give us a call Call: 1-708-460-5884 Text: 708-460-5884 Email: firstname.lastname@example.org If you plan to do it yourself take your time and don’t cut corners, because it is a big job and you do not want to do it twice. Article written by: Scott Flanagan Landscape designer B.S. University of Illinois Ornamental Horticulture