Daily Archives: October 6, 2015

What to do about cracks and control joints in your floor

Every concrete floor has or at least should have control joints in them and just about every floor has at least one crack. So lets start with control joints. A control joint is either a saw cut in the slab or a hand trowel groove. They are there to prevent cracks from happening in  your floor as it expands and contracts. If your floor is relatively new(0-5 yrs) it’s not a good idea to fill them in. Especially when coating your floor with a high gloss epoxy. The epoxy will accentuate any crack that does occur and you know that crack will be right in the middle of your brand new epoxy floor.

Leaving the control joints unfilled gives the floor some dimension and the epoxy makes each section look like a large slab of stone if using the chips or a slab of porcelain if not using the chips.  All you need to do for a control joint as far as epoxying it is just feather the epoxy in and out of the joint with your roller. Don’t try to fill it with epoxy, you just want to coat the sides and the bottom of the joint. If using colored flakes, sprinkle the flakes evenly on either side and your control joint will now look like a natural stone joint.


If you’re floor is older and is done settling and you absolutely just can not stand the sight of those lines then you can fill them in with our Crack & Joint Compound. This is a Part A & Part B liquid that you mix with playground sand you buy locally till it becomes a grout like consistency. Then just use a mason trowel to fill in the joint and scrape it smooth. You use a hand grinder to further smoothen it if necessary after it cures. We would fill in the joints, do any grinding if needed to ensure a perfectly smooth finish, then do the clean and etching after.

If your joints have some sort of material in them it means they are expansion joints and not control joints. The same reasons to fill or not fill apply to these. But if you do want to fill them in you need to use a filler that is flexible such as our Flexible Joint Sealer. This will harden enough to accept a coating but stay flexible enough to expand and contract without cracking.

Finally lets talk about cracks. Even though our epoxy is very thick and will fill in small  cracks we recommend you fill in the cracks anyway. Why, because even cracks that appear to be small may run the depth of the slab and filling them in will take lots of liquid epoxy to fill up and if the crack is all the way through the slab it’s a good chance the epoxy will drip out the bottom. So you may think you filled the crack only to find the epoxy sank in overnight. So best just get some of our Ready Coat Crack Filler. You just mix Part A & Part B together, putty knife it into your cracks and divots and then you can apply the epoxy right over it. No need to let it harden for 24 hrs or more like typical crack fillers.  If a crack is just at the surface then you just coat over those. But if it looks like it goes deeper than don’t take a chance, fill it in, it doesn’t pay not to. On smaller cracks you may want to run a grinding wheel down them to V them out a little.

For large cracks, divots and holes use the Crack & Joint Compound mentioned above. What you don’t want to do is use some premixed retail grade filler in a tub or tube. These types of products always fail and will ruin the look of your beautiful floor when they do. If you have access to some quality product that you mix yourself then go right ahead and use it. Just make sure it’s paint compatible.

For other floor issues and repairs visit our Concrete Floor Repair Page. Everything you need to fix your floor is there. In a future post we’ll talk about floor leveling.

Ordering Enough Material For The Job

Once you’ve made the decision to go ahead and put a coating on your floor, roof or deck the last thing you want to do is run short. We understand that no one wants a whole bunch of leftover materials but trying to order so that you use every last drop of coating leads to problems more often than not. This doesn’t even just apply to the coating, for example, if you were to start building your own deck, you’ll want to make sure you order enough material and items like these you can find at https://www.dinodecking.co.uk/products/low-profile-composite-joist/ and other stores to let yourself make a few mistakes, but not overcompensate to the point of losing money. Let’s just start by saying when it comes to coating concrete floors and wood decks that coverage is not an exact science. There are so many different factors that can affect the amount of coverage you get with any coating that it’s imperative you order material with a little safety factor built-in. Especially when doing wood decks or concrete floors. Wood decks are notorious for soaking up material like a sponge. If your wood is old and dry with lots of cracks in it. Expect to use more material then you think. We would recommend that you use a 20-25% safety factor when doing this type of wood deck. It takes lots of material to fill up all those cracks and dry wood will soak up the first coat similar to when you paint some sheetrock walls where the first coat seems to disappear as it dries.

When it comes to concrete floors the two main factors affecting your epoxy coverage are the porosity of the concrete and the roughness of the surface. Concrete comes in varying densities measured in psi. Your floor can have 3000psi, 4000psi or 5000psi concrete or anything in between. With the higher the psi the denser the floor will be. If you have an older floor with lightweight concrete chances are it will absorb more epoxy than normal, basement floors are notorious for this. If your floor has a very rough finish like a broom finish it will take more material than normal. In either case, it might be a good idea to think about using a primer. A primer will seal up a porous floor and add thickness to a coating to help smooth out a rough finish. That’s why you’ll see on all our epoxy product pages we urge you to add 10% to your actual floor area to be safe. Trying to order the exact amount of epoxy is not a good idea. Just like you wouldn’t go into your local paint store and try to buy the exact amount of semi-gloss to paint a room. You always end up with a little leftover when painting a room(s) and you should do the same when epoxy painting your concrete floors.

Epoxy coverage is usually stated in “up to” terms which means that is usually the most you will get out of the coating. It doesn’t mean that you can’t get more but it’s unwise to plan on doing so. Another factor that will affect coverage is how you apply it. If you apply it a little thicker than normal you will naturally get less coverage. This is not a bad thing as long as you ordered a little extra. It’s always a bad idea to try and stretch out epoxy to get more coverage. This results in less mil coverage than the coating is designed for. Thinner coatings, in general, don’t last as long as thicker coatings. We say in general cause you can apply 10 layers of low-grade epoxy on your floor and it still won’t last as long as even just one coat of our primer!

For interlocking tiles, you want to add 5% to your floor area. This seems to be the magic number for allowing for cutting waste and to have some spare tiles left over. If you are doing a floor that has lots of things you have to cut around you may want to increase the allowance to 10%.

For shingles, flat rubber or asphalt roofs and metal roofs, you can order right around the stated coverage for the product. When coating a roof you almost always get good coverage. Saying this though, if there is more that needs to be done to your roof than giving it a coating, it may be worth getting in touch with an austin roofing company (or one closer to where you live) to get the job done. At times, there are some tasks that are best left to the professionals.

Maybe if you want to be safe you can order an extra pail or two for a large roof. Otherwise when ordering if you round up to the next amount of pails that’s usually enough of a safety factor. Alternatively, you could hire a professional to do your roofs for you and not have to worry about over-spending on materials and worrying about not getting a quality finish to the job, look into commercial roofing companies.

So the moral of the story is you don’t have to go crazy and order a ton of extra material but don’t try to be a Swiss watch maker either. If your floor square footage is anywhere from 80-90% of the stated coverage of the product you’re ordering you are right where you want to be.

Things You Need When Installing an Epoxy Floor

When doing an epoxy floor coating job with any type of epoxy there are certain items you should have on hand. First thing you should have is a cleaner such as Xylene. Xylene is a common cleaner like mineral spirits but it works a little better on good epoxies. If your epoxy is water based then you can use soap and water.

If you are in CA you can buy a Xylene substitute. But in any case you need to have something that will remove the epoxy in case you spill it or splatter it on something you don’t want painted. Especially with our epoxy since once it’s cured it only comes off by mechanical means. So clean up any spills or splatters while the epoxy is still wet. Throw out any rollers, squeegees or mixers right away when your done using them. Good to have a few heavy duty contractor bags on hand or double up your kitchen type garbage bags. When doing a larger floor in a commercial or industrial setting there’s a natural tendency to lean the rollers up against a wall or column or leave the roller sitting in a corner somewhere when your done as you look back and admire your work. Don’t do that, more likely than not you’ll forget about it till the next day when you’ll need a chipping hammer to get it off  whatever you left it on.  We know cause we’ve done it a couple of times ourselves!

Other items you want to pick up at the store before you start your epoxy floor project. Good idea to have a drop cloth to mix the epoxy on, a small plastic one will work best. Some spare latex gloves, they never seem to last long enough. Rags and paper towels are a must. A stiff bristled shop broom for scrubbing the etching solution into the floor.  Thoroughly scrubbing the etc into the floor is key to getting it properly cleaned. Clear measuring containers are a good thing to have so that you pour out accurate amounts of the Part A & Part B of the epoxies. Get containers that are at least 100 ounces or more.

When doing a floor with color chips in it we always recommend you have spiked soles. It’s much easier to get a good even pattern when using spikes. Our Armor Granite kits come with spiked soles. We sell spiked soles separately but you can use an old pair of golf shoes if you have any. We also supply spikes for floor orders over 1500 Sf.

Other items that you will need such as rollers, mixers, squeegees and mixing buckets come with our epoxy kits. All the additional items mentioned above are inexpensive but will go a long way in making the job a lot easier.