Potential Issues with Coating

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Potential Issues with Coating Concrete, Wood, and Foam:

This section is mainly going to cover coating concrete, but there are side issues with wood, foam, and plastics that will be mentioned. All of the information is good for anyone bidding coating projects, and it is good to remember how wood, foam and plastics are involved a lot of the time when doing concrete coating.

Coating concrete on industrial floors can bring out certain concerns, the biggest is what to do with the exposed metal issues that are always different in shapes and sizes, but are involved in almost every industrial floor. It is the same when addressing metal supports, equipment footing, and metal bracing, they will always be in different areas and need to be addressed. The last issues are the pipe and equipment discharges of toxic or very corrosive liquids. The concrete around these areas is almost always deteriorated, but they are part of the floor and again, each item needs to be address in the same manner. 

First make a list of all the issues your client has:

Your Client wants to address their issues and concerns to you, make a list and do not add or subtract from that list at first. Now walk around and make a list of your own.  Next, compare the 2 and see if there is anything on your list that you need to address with your client. Things to always look at are; How smooth or level is the existing concrete. Does the concrete have good slope to drain off water; are there pot holes or low spots that will affect the end results. If these issues are not addressed now, it may cost you the project, and if you do not address the issues, it may lead to legal issues. Any pot hole or standing water can cause a client or employee to slip and fall and that is a problem. You have to bring these kinds of issues up with the client, because it is going to cost money to fill them, or possibly a need to reslope the area to allow proper drainage of the coated floor. There is nothing worse than applying a coating to find out there is a large pot hole or drainage issue on the floor just coated. If you can fill the pot holes for almost no extra material or labor, just add it into your bid and sign a contract to perform the requirements of the project. If the cost of sloping and filling the pot holes is too high for your client, it is better to walk than get pulled into a legal issue on a slip and fall issue.

Preparing concrete for applying Durabak 18 non-slip

The best way to prepare concrete is by shot blasting. That being said, another good way is to pressure wash the area if there is good drainage or vacuuming up the debris is acceptable.

If water can be used safely; A Clorox rinse of one cup of Clorox to a gallon of water, sprayed out with a garden sprayer, keeping the surface to be coated wet for at least 20 minutes, will get the prep started. After the Clorox rinse, follow it with a horizontal/vertical pressure wash at 2500 psi using a 15 degree nozzle; that will remove and clean at least 95% of all dirt, grease, oil, and grime from the surface of the substrate to be coated. When the surface is clean and dry, then perform the 2 inch patch test. Click here to review the 2 inch patch test

What to look for when determining Dry mil application thickness of Durabak 18

It is always important to look at what kind of traffic is going to be on the floor coating and how heavy the load bearing forces are going to be. Will rubber tires or steel rollers be rolling over the floor coating? Will there be fork truck traffic running over the floor, and where will this equipment be coming from, and going to? Will there be quick turns being made on the floor coating? Where will it be happening? Now there may be a hundred other factors to consider, so it is always important that pictures are taken, and a quick floor layout is made to determine how thick the coating needs to be in which areas and to note whether or not the different thicknesses will cause standing water or floor sloping issues. These are all important issues to make note of, because the heavier the equipment usage and the heavier the equipment, the thicker the coating has to be in that area to support the coating and usage. In general, 80% of a warehouse has almost no or very little actual traffic in them. They are laydown areas and although heavy loads may be placed on them, there is very little to no movement on them. 10% of the area will have little to moderate foot traffic, and 5% will have heavy load bearing requirements, and only 5% will have extreme load bearing requirements when it comes to applying a coating to a floor. So now with a map of the laydown area, foot traffic area, and what kind of fork truck movement is on the other 5% of the area, you can go to work laying out the thickness of the coating to be used in this project and how many gallons of material it is going to take to get the project done.  Please call us (at 201-379-5366) for more input on your project. We are here to make each project simple and easy to get done.

Application dry mill thickness vs  weight applied to floor coating

Before talking about dry mil coating thickness, let us talk about per cent of solids in any liquid coating

When applying products that are 100% solids if you put down 10 wet mils you will get roughly 10 dry mils.  If you put down 15 wet mils of Durabak 18 it is going to give you roughly 10 dry mils, because Durabak 18 material is 67.7% solids, or roughly 68% solids.

Now let us also talk about application rates

A gallon of liquid is always 128 oz of material.  When that material is applied at 1 wet mil, it will cover roughly 1086 sq ft. When applied at 5 wet mils it will cover 350 sq. ft. When applied at 10 wet mils it will cover 160 sq. ft. When applied at 15 wet mils it will cover roughly 110 sq. ft. When dealing with Durabak 18 smooth, the above numbers work well, if no other factors apply to the surface of the substrate. When dealing with Durabak 18 non-slip, it is important to understand that there is roughly a quart of liquid taken out of each can, and a quart of rubber chips are added. The rubber chips require wetting of their surfaces, so in all roughly 80 oz of the 128 oz. normally in a gallon is left to spread at 15 wet mils. So a gallon of Durabak 18 non-slip will only cover roughly 65 sq. ft. per gallon.

Now let us talk about substrate surface profile

Almost all application rates are typically based on the ISA 120 profile. It is a standard used by most industries to determine application rates. When the surface profile varies the application rates will also. If the surface is better than a 120 profile the application rates will go up. Likewise, if the surface profile is worse than 120, the application rate will go down.

Concrete and wood can vary greatly, they need to be looked at before estimating the volume of material needed for a job. That is why shot-blasting concrete is such a good idea, it will take the high points off the concrete, and less material will be lost into the surface profile. Wood usually needs to be sanded to avoid this issue. Open and closed cell foam have real issues with surface profile and surface porosity. In the case of wood and concrete, the dust has to be removed before the surface can be coated. That is why it is important to do the 2 inch patch test.

It is important that we talk about surface porosity

Most of the time it can be ignored, however in some cases it becomes very important, and can cause a project to use twice as much product as normal. To be clear, surface porosity is the number of very small holes in the surface of a substrate and the diameter and depth of those holes. If these items are all small, you will only lose .25 to maybe 2% of the product down into the surface porosity. However if you have CDX unfinished or marine grade plywood, the % of loss can be 10 to 20% of the material, and if you combine this loss with surface profile of CDX unfinished or marine grade plywood the material filling the large holes, and the material needed to cover over or fill in the small valley on the surface of the wood can be easily 35 to 40%; This loss of covering the high points of this kind of wood can cause these kinds of materials to fail.   For example typically a gallon of Durabak 18 non-slip will cover 65 sq.ft. at an application rate of 15 wet mils. Here, you may only get 30 sq. ft per gallon to apply 15 wet mils over the top of the highest peaks in the valley of the wood.

This is why it is a good idea to belt sand rough grade woods before applying any coating to them

However, there is a secondary issue to take care of when sanding wood; that is getting all of the dust off and out of the surface of the wood after sanding it. If the wood dust is left on the wood, the Durabak 18 will stick to the wood dust and not to the board fibers and pulp and it will release or delaminate. That is why any prep needs to have the 2 inch patch test run on it, and it is very important to do it on sanded wood.

Sometimes it is a requirement to grind concrete

When grinding is involved, removal of the dust has to happen or it will cause delamination of the Durabak 18, because the Durabak 18 will bond to the concrete dust and not to the surface profile and surface porosity of the concrete substrate.

Coverage of a gallon of Durabak 18:

A gallon of Durabak non-slip will cover about 60 square feet, at 15 wet mils (or 2 coats at 8 wet mils each- the recommended 2 coats). A gallon of smooth Durabak will cover 110 sq ft at 15 wet mils. Note: As a hint, a 3/8 inch nap roller cage will apply Durabak 18 smooth at roughly 12 to 15 wet mils naturally. A 3/16 inch lamb skin roller cage will apply Durabak 18 smooth at roughly 10 to 12 wet mils naturally.

When applying Durabak 18 non-slip, the Cote-L stipple rollers (available HERE) will apply roughly 12 to 15 wet mils naturally. A quart of Durabak non-slip will cover 15 square feet at 15 wet mils. A standard 2 inch chip brush will apply roughly 12 to 15 wet mils. A very good horse hair or filament brush will apply Durabak 18 at about 5 to 10 wet mils, depending on how wet the brush is and if the area is back brushed. These numbers are subject to some variability due to external factors, such as the porosity of the surface. 

Normal drying time vs temperature and humidity for Durabak 18:

A standard application rate for Durabak 18 material is 15 wet mils. At this applied rate, on a 70 degree F day at roughly 30 % humidity, You can expect the surface to be tack free in roughly 40 minutes, dry in 55 minutes, and ready for recoat in roughly 65 minutes. Never apply Durabak 18 at less than 8 wet mils thickness, or it will take hours if not days to cure out. If Durabak 18 is applied at less than 8 wet mils, use spike shoes and recoat at 8 to 12 wet mils. Your drying time will come in at roughly 60 minutes. You can apply Durabak 18 at a thicker application rate, but your drying time will go up.  During a working day, 15 wet mils is recommended to get the most work done and to ensure the toughest material when cured out. Applying Durabak 18 at 25 to 30 wet mils should only happen when there is at least 8 hours for an area to dry and cure. Make sure the area is secured, that no one will walk over the surface until it is at least tack free. When building up layers to meet designated dry mil thickness to handle the abuse of the traffic load, time is your enemy. The quicker you can get back onto a floor for build up the better it is for everyone. Thicker application of Durabak 18 is not recommended unless you are very experienced with Durabak products, and all of the conditions are just right to allow the material to dry and cure out correctly.

How atmospheric and substrate temperatures affect the project:

If the temperature drops to 55 degrees F, you can expect drying times to go up to several hours. If the temperature get above 85 degrees, it will also slow down the drying time. Note that atmospheric temperatures maybe in the 65 to 85 degrees range, but the substrates may be 10 to 20 degrees colder or hotter than atmospheric temperatures so although the air is 70 degrees F, always look at the substrate temperature. Sometimes the application and drying times need to be adjusted for substrate conditions. You may have to start multiple areas of a project to get the job done on time.  For more specific input and suggestions on your specific job, call 201-379-5366. We would love to support you in your job!

Below, is a table addressing (estimated) dry mill thickness to traffic loads.


Light to moderate personal traffic:                                                       10 dry mils

Commercial walking traffic:                                                                   20 -25 dry mils

High corner traffic:                                                                                 25 -30 dry mils

3500 lbs fork truck traffic general straight path traffic:                       25-35 dry mils

3500 lbs fork truck traffic around the end of shelving:                        45-50 dry mils

3500 lbs fork truck traffic at loading dock area:                                  50-55 dry mils

3500 lbs fork truck traffic on diamond plate at loading dock area:   55-60 dry mils

6500 lbs fork truck traffic:                                                                     55-60 dry mils

10-12k lbs fork truck traffic:                                                                  65-70 dry mils


Maintenance agreement  vs single one time contracts

In any commercial or industrial application, it is better to sign a 2 to 3 year maintenance agreement. With a 3 year agreement, the first year you go in and do the best job you can do. Now it is wiser to not put any coating down above 45 dry mils unless you have specific reasons the first year. The second year you repair the areas need repairs.  Here is where if the material is dirty you may add 15 wet mills. If the material is totally gone, you can apply 5 layers at 15 wet mils each. The third year, the amount of repair is usually only 2 to 7% of the total area. So the first year coat the total area with 25 dry mils, and then coat heavy load areas to 35 dry mils and corners, loading docks and diamond plate area to 45 dry mils. The second year there will be some areas to repair, but the total repair area is usually 4 to 15% of the total area. The traffic patterns are made clear, and the real heavy traffic conditions will be very clear. You will need to address each area individually. The pay-off for you and your client is the amount of product used if you're guessing vs the amount of product used if you know. The cost of guessing is always 65 to 110% higher than reality, and this difference usually means the proposal is turned down. A 2 to 3 year agreement allows the client to spread the cost of work done, out over a longer time making the project affordable, then your client can get a good idea of your commitment to him, and getting a job done well. The cost of going into a work area 2 or 3 times if done for good reasons will be acceptable. If you take the first visit at 100% and give it a value of $10,000 dollars, the cost of the next visit can be $2,000 to $7500.  Whereas, if you guess at it the first time, the cost might be $20,500, and you will be back the 2nd time anyway, and now you're into a dispute as to who is going to pay. A typical 3 year contract will normally look like $10,000 the first year, $4,500 the second year, and the $1,500 the third and final year, or a total of $16,000 and you have given your client a floor that will last 10 to 12 years with no additional work unless the floor traffic changes for some reason. Now you have a client that will remember you for the right reasons.