Frequently Asked Questions About Paving Stone Installation & How To Choose A Contractor.

From Award Winning Professional Installer, Giuseppe Abbrancati
Information that you want and that you should know.
GAPPSI is a customer service oriented company with dedicated employees. Every employee’s responsibility is selected in order to guarantee our customers quality services and satisfaction at the completion of every project installation.
Paving stones are best installed on recycled concrete base or RCA which is produced from the recycled process of concrete removed from old concrete patios, driveways and street sidewalks. It comes in sizes of 1 ¼ inch clean and in ¾ inch mix with finer particles. Patios and walkways will take a 6 inch deep RCA base and a driveway will need 12 inches total, 6 inches of (1 ¼ clean crushed) as a bottom layer because this will help stabilize the sub-base below and then 6 inches of ( ¾ minus) over it. The finer crushed concrete or RCA, once compacted with a vibrating plate compactor or roller and sprayed with water during compaction it will petrify like a natural stone do to the high concentration of cement and calcium that is present in the RCA. Then 1 to 1 ½ inches of sand is leveled over the RCA and the paving stones are then laid over the sand. These are the industries standards of installation. But what makes the difference between a good installation and a bad one is the installer. It takes more than crushed concrete and sand. The installers experience, knowledge, tools and long term plans to be in business is what delivers a good job.
WHAT IS RCA? (Recycled Concrete Aggregate)
Crushed concrete or RCA is produced by private crushing concrete facilities. Some facilities select the materials before crushing them and charge more for that particular RCA but they also crush concrete mixed with lots of dirt, grass and every thing else that contractors excavate from their job and bring to them. It may cost too much to separate them so they crush them and then they sell it much cheaper and they also call it RCA.
There is no industry standard for RCA used in residential applications. It comes down to the contractors conscience to pay a little more to get the better product and deliver a better job. The best RCA is made by mixing 70 % of pure crushed concrete and 30% of sand and gravel because the concrete petrifies and the sand and gravel gives the base its porasity so the water can travel through it to the ground below. State approved RCA is not good to use as a base under the paving stones because it is 100 % crushed concrete and petrifies as a solid base and water does not seep through it for drainage.
Second most important factor after the selection of quality base material is the compaction of the base preparation. To do a good compaction you need a good compactor plate or roller and spraying a substantial amount of water to the base during compaction helps the base material densify and petrify. Base material should be very close and consistent with the final grade of the finished pavement. It should take only 1 to 1 ½ inches of sand throughout the paved area . Quality Base material, good compaction and grading is what a good long lasting installation is all about. Recycled concrete base is a flexible base, it will heave in frost situations and it will return to it’s original position in a thawing situation. Also, good RCA base, once petrified will allow any water that seeps between the joints of paving stones through the sand to drain into the ground below allowing water to drain from underneath paving stone pavement. Water drainage is very important for the preservation of paving stones colors and finishes.
If you have an existing concrete patio with some cracks in it, you can use it as base and install pavers on it over one inch of sand as long as you have an open clearance under any door or gate that opens on to the patio. You will increase the height of the patio by three inches so the existing grass touching the patio will have to be adjusted if necessary. When installing paving stones around a pool, the ground around a new swimming pool gets excavated almost 3 ft deep and 3 to 4 ft wide all around the pool. It does not matter how long you wait. 3 ft of back fill will keep settling for years and so will be the patio unless a concrete base for the patio is installed the proper way. To do it to prevent settling is to compact the ground as much as possible with a vibrating plate machine, tie rebars to the top of the pool walls on steel walls and drill holes into walls if the walls are poured concrete. Then tie concrete wire mesh at least 4 to 5 ft around pool and then pour 4 inches of concrete base. You can install concrete or install RCA for the remaining patio area. I strongly suggest that you have concrete base around the pool to prevent settling and RCA for the remaining area so the water that gets underneath the pavers will drain into the ground below so it would not get trapped under the pavers and affect the colors and finishes of the paving stones in the future. If you install concrete base for the entire area the concrete has to be sloped in the same direction as the finished patio and drilling lop holes under the border will allow the water to escape from underneath the paving stone. Or, if you install the Gappsi Edge Restraint System you will have consistent drainage all around the patio. You have to follow the same procedures of installing 1 to 1 ½ inches of sand over the concrete before installing pavers.
After the base preparation spreading 1 to 1 ½ inches of clean sand over the RCA, level the sand to create a more precise final grade proceeding with installation of paving stones. Installing sand under paving stones is for several functions. The sand works as a separation between pavers and RCA . Since RCA is rich in calcium and lime, separating pavers from the base with clean sand will prevent pavers from absorbing lime and calcium from base materials which will show up to the surface of the pavement as efflorescence. New paving stones will release lime coming from within the pavers themselves for a period of one to two years and then eventually disappear. If pavers are touching concrete or any kind of cement enriched base material the efflorescence factor will increse as years go by. Another function the sand has is that water that gets under the pavers it will travel through the sand faster and find its way through the RCA base into ground. Also, after the installation and completion of the paving stone pavement, sweep dry sand to fill the joints of the paving stones, vibrate pavers into the sand with a vibrating plate machine. This will allow the dry sand to fill the joints of the paving stones. This will create an interlocking pavement system, paving stones are not consistent in thickness. The compaction of paving stones will push any higher paving stones into the sand and in this situation the sand works as a cushion allowing thicker paving stones to be vibrated lower so the top of the patio is all even.
Installing RCA base under a paving stone driveway will allow good water drainage into the ground below. You have to use at least 12” of RCA base material and you will definitely need to have a good and heavy mechanical compacting machine. The base must be compacted several times. If you are concerned about settling and if having a poured concrete base under your paving stone driveway makes you feel more reassured, there is nothing wrong with doing so. When installing a concrete base under paving stones, make sure proper drainage is created and that water is allowed to escape from underneath the paving stones. Installing the gappsi edge restraint system around the perimeter of your paving stone installation will allow full drainage anywhere the border of the paving stone pavement abuts the grass or a flower bed and water will escape and drain into the ground. As long as you create drainage so water can escape from underneath the paving stones, a concrete base under paving stones won’t affect the installation or the paving stones long-term integrity.
1) Install drywells under concrete in low spots with a drain crate over it so water can access in to the drywell and escape from underneath the pavers. The top of the crate should be below the bottom of the sand with landscape fabric over it so water will drain and sand will be kept from washing out in to the drywell.
2) You can install a water catch basin under the concrete with top of crate below bottom of sand with landscape fabric over it so sand won’t wash away and pipe water to a drywell under the grass next to the driveway and at the same time you can pipe water from a roof gutter into the same drywell to prevent water from running over the brand new paver and stain, mark and weather the pavers over the years different from the rest of the driveway
3) It is very important to do the same for the driveway apron so water that travels under the pavers once it hits the curb will be cached and directed to a drywell. All driveways slope towards the street and a good way to do it is to install a French drain. Dig a 12“ wide x 12” deep trench next to street curb as wide as the driveway apron. Line the trench with landscape fabric and install a perforated 4” pvc pipe across the entire trench past the finished driveway and extend the pipe to connect in to a drywell in the grass. Fill the trench with washed gravel and then rap the fabric over the gravel. Then pour concrete over the fabric. You need to install a two by four against the concrete curb so after the concrete cures you remove the wood. A two inche gap is created between the concrete base and curb. Install pavers over the concrete on 1 to 1 ½ inches of sand. The fabric that you wrapped the gravel with will prevent the sand from washing away in to the gravel. If you don’t follow this procedure the water that travels underneath the pavers will back up under the paving stones driveway and come up through the joint of the paving stones. This water traveled all the way down from the top of the driveway carrying with it all the lime and efflorescent released from the brand new concrete base. And if not direct and let this water drain from under pavers this will discolor the pavers and the steeper the degree of slope of the driveway the faster the water travels under the pavers towards the street.
These are pictures showing efflorescent create by concrete base with no drainage system under pavers.
The three biggest differences between paving stone manufacturers are:
1) The owners of each manufactures have different last names.
2) They deposit their millions in different bank accounts
. 3) While every contractor in the field butts heads against each other trying to explain to the consumer the differences between manufacturers, the owners of every paving stone manufacturer are having partys on their yachts laughing at it all.
Paving stones or interlocking paving blocks are manufactured with high density cement mix which consist of sand, cement, color and water. These are the ingredients used to make paving stones with every paving stone manufacturing facility worldwide. Cement mix is poured into a mold and pressed by hydraulic power over a vibrating plate. The manufacturers that make the machines to make paving stones is who all the credit is due. Through their research and technology they develop new state of the art paving stone machines and molds every year making the products more realistic like. Tumbled stone looks more edged than broken stones making colors more vibrant and blends more uniform making paving stones look like tiles by polishing the top or sand blasting the surface to create the resemblance of a natural weathered stone. The difference between the paving stone manufacturers are mostly their color blend, they all use colors to make blends in different percentages, they are located in different states and get their sand to make their paving stones locally, so their sand is different though making a difference in blends and colors results. Their shapes my be different, it depends on what kind of shapes each manufacturer decides to promote.
Their finishes depend on what kind of finishing machines they decide to adapt. Whether they want to produce polished, natural, chiseled edges, beveled edges, tumbled or sand blasted paving stones in our showroom we decided to carry Nicolock, Anchor and Hanover paving stones and wall systems.
We carry these three companies for the difference in their product lines:
We like Nicolock because they have the biggest selection of colors and the biggest selection of three color blends, biggest selection of fullnose and coping, they produce chiseled edges and natural finished paving stones, they have the biggest selection of colors and styles of retaining wall systems, are a local manufacturer and their products are available to us within hours.
We like Anchor for their color blends being totally different from the Nicolock line, they manufacture natural and tumbled finished walls and paving stones. Anchor tumbled stones are true tumbled, they have a perfect weathered look resembling real stones in rustic and soft weathered finishes. Very unique shapes like Portage, The Arbel and Urbana. They have a big selection of engineered wall systems and a very big selection of patterns.
We like Hanover for their color selection for being totally different from Nicolock and Anchor. They produce chiseled edges, tumbled and sand blasted paving stones. They make very unique shapes like the cathedral, the fan pattern and most realistic slate finish sand blasted paving stones in gray and beige blend in sizes ranging from 12 x 12 to 24 x 36 Their chapel garden wall system is most natural looking wall system on the market, very consistent and uniformed color blends. In addition, they have a large selection of custom finished pool coping.
Choosing the Pavers: Choosing your paving stones could be quite a challenge. I say that because of what I have experienced through the years of listening to people’s comments about how overwhelmed, confused and frustrated they are trying to choose pavers for their project. That is because people trying to absorb to much information given to them by contractors that they interview and stone dealers that they visit. In many situations contractors favor a certain manufacturer because of certain interests like trying to be loyal to a dealer where they buy their supplies and get referrals from so in return they push their products. Dealers sometimes have territorial rights and that’s why they promote certain manufacturers.
For this reason, it could be very tiring selecting your stone when listening to contractors and stone dealers talking about which paving stones manufacturer is better when 99% of the problem that people have with paving stones are installation problems. That is due to the poor knowledge of several contractors. In many situations consumers wear them selves out trying to choose their paving stones. In the end they wind up buying what the installer they are hiring to do the job suggests.
My first recommendation to consumers that are looking to choose paving stones is to visit as many paving stone dealers as possible and look at their displays and do not ask any questions. The paving stones that you are going to use is the one that is esthetically appealing to you whether it is the color blend, finish, texture, sizes or pattern. Because, if you ask somebody else, that person is going to try to sell you what ever interests him. And I guarantee you that nobody knows better than you about what you like.
The next and best recommendation is that you choose a company first that you think is very qualified to handle your project and then let them guide you throughout the process of designing, selecting materials and installing your project. This way you are dealing with one company and if any problem arises from paving stones or craftsmanship you don’t have to run around trying to figure things out.
Paving stones are manufactured concrete blocks. The ingredient to make paving blocks are sand, cement, color and water. Just like natural stones, paving stone colors change from lot to lot, so when you look at a stone display there is a good chance that you will get something a little different than the color of stones that you chose.
That is because colors, cement and water are possible to manage during the manufacturing of paving stones, but sand is not, just like you see different veins of colors when you look at a big rock the color of the sand changes the same way when you dig through a sand mound thus having different colors of sand everyday and that is why the color of paving stone changes from lot to lot. When you chose a paving stone you should be open minded, and I say this respectfully, and also because is beyond everybody’s control from your contractor to the supplier to the manufacturer. Most people that have problems with stone colors is because they were never told what to expect. The colors of your paving stones will be within the range and tone of colors that you chose when you saw them displayed.
Also, what makes the color change is the temperature. If the weather is humid or dry that has a big impact to the curing process of cement thus to the end color result and this could affect the colors of paving stones not from lot to lot but from pavers made in the morning verses pavers made in the afternoon within the same lot during the same day. If you use different size of stones for the border or for inlays but the same color of the stones that you are using for the middle of the patio, you will get a different color border or inlay because is it is a different size stone and it is definitely a different lot . Colors of fullnose are always different than pavers because they are manufactured standing up and pavers are manufactured laying flat. Fullnose are also smoother and that affects the colors.
Lots of people choose their paving stones by looking at one or two samples that is not a good thing to do. Lots of people try to justify the colors printed on the brochures comparing them to the actual pavers. When a picture is a reproduction it is very easily affected by lighting and cameras lenses. In conclusion, I have seen people suffering in pain while trying to chose their paving stone colors and I have had out of body experiences just by looking and listening to them to the point of saying that there are bigger problems in the world than the color changes of the sand.
Selecting a contractor to install your home improvement project is the most important part to guarantee yourself a satisfactory end result . Hiring the lowest bidder my not be the smartest thing to do and hiring the highest bidder does not necessarily mean that you are going to get the best job. Being the middle bidder does not make that the right guy either.
Hirng a company that has been in business a long time may be the right thing to do, but consider that management changes and some times a new company with no background may deliver a better job because they are tryng to build up a name. But Remember that years of experience is what gives knowledge. Getting references is a good idea but remember that nobody will give a reference that will bad mouth them.
An average home improvement project takes approx. 10 days to complete. People spend a long time to choose their companion that they are going to spend the rest of their live with, they do not spend too much time selecting a contractor because it’s only going to be a short encounter. They do not consider the fact that they are going to look at the project for a lifetime. And thery are going to spend a long time working to pay for it.
1) Your contractor should volunteer, without you asking, proof of home improvement license, liability and workmans comp. certificate. If somebody gets injured working at your house and the contractor you hired does not have the proper insurance, the home owner is personally responsible and if the contractor does not have a home improvement license, the home owner can not bring any legal action against the contractor, because the contractor can claim he is not a contractor and he was just helping you. A signed contract of the work that as to be performed is a must.
2) If you ask for a reference or if the contractor volunteers them it should be a list of over a 100 names and phone numbers.
3) The contractor should volunteer to give you his cell number and that number should be printed on his business card. Before you hire him, every time you call him, you should call him from different phone lines.
4) If you really want a reference, it is better to go see a job in progress and to see the contractors way of operation and make the contractor aware that you will call him unexpectedly to see a job in progress. He should not choose the job you are going to see.
5) Checking with Consumer Affairs and the BBB is definitely a way to check your contractors background.
6) If your contractor has a PO Box as an office address, that address could disappear overnight as well as the the contractor. If you need to take legal action against them it would be literally impossible.
7) If your contractor has an office where somebody answers the phone during business hours when you need to call with a quick or important question, that definitely shows dedication to costumer service.
8) If your contractor has an office where you can go in person, in case you can not get through by phone – that is definitely reassuring!
9) If the company you’re planning to use owns the place of business, where the company is established and a showroom, where you can walk in and out, that definitely shows customer service and dedication. That is your guarantee that you are going to get a good job. You can rest assure and go on doing what it is that you do for a living with out being distracted because you are having work done at your home and at the same time save money for not wasting time and work days to check on the contractor while they are working at your house. Sometimes what you think you are saving you might be wasting it.
10) The last thing you want to do is to be involved in ordering any materials and be part of scheduling and delivery of supplies such as containers, sand, gravel, and paving stones. It does not seem to be a big deal, but trust me it is. you. You want your contractor to handle every thing, all you want is to do is come home and like what you see and be picky about it if necessary.
Paving stones are best installed on recycled concrete base or RCA which is produced from the recycled process of concrete removed from old concrete patios, driveways and street sidewalks. It comes in sizes of 1 ¼ inch clean and in ¾ inch mix with finer particles. Patios and walkways will take a 6 inch deep RCA base and a driveway will need 12 inches total, 6 inches of (1 ¼ clean crushed) as a bottom layer because this will help stabilize the sub-base below and then 6 inches of ( ¾ minus) over it. The finer crushed concrete or RCA, once compacted with a vibrating plate compactor or roller and sprayed with water during compaction it will petrify like a natural stone do to the high concentration of cement and calcium that is present in the RCA. Then 1 to 1 ½ inches of sand is leveled over the RCA and the paving stones are then laid over the sand. These are the industries standards of installation. But what makes the difference between a good installation and a bad one is the installer. It takes more than crushed concrete and sand. The installers experience, knowledge, tools and long term plans to be in business is what delivers a good job.
It is whitish powder-like deposit which sometimes appears on concrete or clay products. The deposit is the residue of a soluble salt carried to the face of the product by moisture and left on the surface as a dry powder following evaporation of the moisture. The phenomenon was reported on as early as the 1870’s. Efflorescence of itself in no way affects structural integrity.
The salts are found in either the native soil, the gravel base or in the sand, stone or cement used to manufacture the paving stones.
These salts dissolve in either the ground water, rain water or water added to mix the concrete. The salts move upwards with the moisture to the drying surface by capillary action. In basement walls, this capillary movement has been measured to be as much as 600 millimeters. Because the sun evaporates the moisture at the surface, this capillary wicking action continues to draw moisture from below. The efflorescence continues until either the salt of moisture supply has been exhausted.
Efflorescence will usually wash and wear off in the course of time. The recommended procedure is to allow this natural process to take place. However, if you would like to speed up the process, it can be removed by washing the pavers with efflorescence remover solution. This solution is available at our supply location. A small unobtrusive area should be treated first to ensure results are acceptable.
No responsibility can be accepted by the paving stone manufacturers or the installer for efflorescence since any normal concrete contains calcium hydroxide which is inevitable when cements and/or lime and water are mixed together. Calcium hydroxide combines with carbon dioxide in the air to form calcium carbonate which then appears as a whitish deposit, efflorescence.
Reference: Portland Cement Association
Bulletin 1A020.03T
MY ADVICE TO YOU is to consider the whitish color of the efflorescence as the white color of the blend you chose. White is a color that you will always get with any paving stones that you purchase. There is nothing to get upset over and spending time and money trying to remove it. Accept the white of efflorescence as an additional color to your paving stones. If the efflorescence that occurs with paving stones is NOT acceptable to you, then you should strongly consider using Travetine, Granite, Marble or any other natural stones

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