Removing Tar Roofing & Installing Cementitious Waterproofing

Posted below is a recent video clip of some pictures of a recent concrete waterproofing job we completed. Our client had a concrete building with a built-up tar and gravel roof that he wanted to remove. They were planning on using the roof as a useable space consisting of a sitting area and areas that will be converted into a garden.

Stage one was to remove all of the tar from the roof, and install membrane c waterproofing cement. This is to get the general roof top waterproofed. The next stage will be to build cinder block planters and then add another coat of membrane c to the planters.

Check out the video below.

Click to view more waterproofing jobs.

 

 

Epoxy Crack Injection

If you have vertical or horizontal cracks in concrete your best method to seal them would be to use an epoxy crack injection kit. Sealing the cracks in concrete will help prevent water from soaking in and causing harm to the rebar.

The first step when rehabilitating concrete using the epoxy crack injection method is to use an epoxy paste to close the outside of the crack. While doing this you will also install injection ports approximately every 8″ apart. Sealing the outside with a paste will help prevent the lower viscosity epoxy from spilling out when you are injecting into the ports.

Once the epoxy paste hardens fully you will use a caulk gun to dispense low viscosity epoxy into the concrete starting at the lowest point. The low viscosity will allow the epoxy to penetrate deep into the concrete bonding everything back together.

After letting all of the epoxy cure you can chip off the ports and grind any excess epoxy flush with the concrete.

For more information feel free to contact us at mvlconcrete@yahoo.com .

Epoxy Crack Injection

Epoxy Crack Injection

 

 

Trying To Repair Alkali Silica Reaction In Concrete

How do you repair alkali silica reaction in concrete? I wish there was a simply solution to achieving that. I had a homeowner call and tell me she was having small modules of gel leaching out of the concrete, and over time the gel would harden. She had an engineer come out and take samples of the concrete, they determined that she had alkali silica reaction or (ASR).

So I went over to the house to take a look at the problem and was amazed by what I saw. Take a look for yourself:

Alkali Silica Reaction

Alkali Silica Reaction

I’m sure you can figure out why this might be a problem. For starters she has a decorative overlay in the house that is peeling off because of this reaction. She also has sticky gel all over her floor which makes it difficult to keep clean. She asked if there was any way to prevent the gel from re-appear.

I asked a couple of different suppliers and manufactures about what can be done to stop this. For the most part they all told me the concrete has to be jack hammered out and re-poured, which is not feasible because the house is already built and she is living in it.  One person told me I can use a product called Aqua Block and that might help.

I told the homeowner I would not mind messing around with it seeing if anything will help the situation. I suggested to grind the concrete down where the ASR was happening, which happens to be where all of the structural beams are. After grinding the concrete I left one area untreated and another area I treated with Aqua Block to see if that will help at all. After a couple of months I will go back and check to see if their is any improvements. If anyone has any suggestions or questions on this issue please email me at mvlconcrete@yahoo.com.

Alkali Aggregate Reaction

Alkali Aggregate Reaction

Ground Concrete Exposed Aggregate

Ground Concrete Exposed Aggregate

Testing Aqua Blocks Treating ASR

Testing Aqua Blocks Treating ASR

Applying Aqua Blocks On Ground Concrete

Applying Aqua Blocks On Ground Concrete

 

 

 

Preventing Spalling Concrete In Parking Garages

Spalling concrete can be a major issue in parking garages. Unlike concrete buildings that receive a curtain wall protecting the inside concrete floors from the weather, parking garages are open to the elements of the weather. Since the concrete parking decks are opened to the weather is it especially important to place the rebar in the correct locations and have enough concrete covering them.

A protective treatment that can be done to the parking deck after the concrete has been poured is to apply a waterproofing membrane to the concrete. This membrane will prevent water that is sitting on the concrete parking deck to leech into the concrete causing the rebar to corrode causing a spalled area. This membrane can be applied right after the concrete has cured or years after. This investment will protect the parking garage from future spalling problems that could potentially harm a pedestrian.

For more information please visit are website: http://mvlconcrete.com/concrete%20restoration%20-%20san%20antonio.htm

Concrete Spall Repair in Parking Garage

Concrete spalling is very common in parking garages. The spalling occurs when the rebar in the concrete starts to corrode due to water seeping into the concrete. As the rebar corrodes it expands causing a piece of the concrete to break off.

Overhead spalling concrete can be dangerous to occupants in the parking garage. Pieces of concrete could fall and hit someone causing a lawsuit. It is relatively easy to repair the spalling concrete in the parking garage if done sooner than later. When rebar corrodes it could spread causing bigger areas to spall off.

The pictures below is an example of an overhead piece of concrete spalling in a parking garage. We offer parking garage restoration services in San Antonio, TX.

Spalling Concrete Parking Garage

Spalling Concrete Parking Garage

 

Parking Garage Repair

Parking Garage Repair

 

 

Spalling Concrete Underneath Exterior Stairs

A common area for spalling concrete is underneath exterior formed concrete stairs. The spalling is caused by water seeping into the concrete corroding the rebar. As the rust forms on the rebar it expands causing the concrete to break off.

To prevent this from happening, you should have the top surface of the concrete stairs waterproofed. Waterproofing concrete involves prepping the concrete and then troweling on a special waterproofing cement. This will help prevent water from soaking into the concrete corroding the rebar.

Resurfacing Over Mud-Base For Wood Floors

This week we prepared a mud-base for wood flooring. A mud-base is a cement-sand mixture that is fairly soft and brittle. The mud-base was placed because the home builder did not build the front entrance of the house higher than the outside patio, so to bring the floor up in the house they placed a mud-base and then tile.

During the tile removal the mud-base got chipped up in some areas as well. There were a lot of gouges in the mud-base that had to be filled and also leveled. The homeowner had two options he could either remove the 2 1/2″ of mud-base and place concrete or repair the mud-base for the wood floors.

They decided to repair the mud-base. To do this we had to coat the entire surface with an epoxy to make sure the mud-base would not break apart, the epoxy also helps the special repair mortars bond properly. After applying the repair mortar to fill all of the gouges we applied a self-leveling underlayment to finish off the repair.

Take a look at the video below of the job:

Old Polished Concrete Patio Needing A Renovation

This was a very old concrete patio at a house designed by O’neil Ford in San Antonio, Tx. When they poured the concrete they seeded the top with green marble chips. When the concrete hardened they came back with a grinder to grind the concrete and expose the marble chips. This gave a similar look to Terrazzo Flooring. Over time the concrete eroded and some of the marble chips were popping out leaving small pits on the surface.

The first thing we did to renovate the concrete patio was applied a grout to the surface to fill the pits. We then ground the concrete and honed the surface to a 400 grit finish. The homeowner did not want to polish the concrete to a very high level because the patio was close to a pool and could be slick when water was on the surface. Honed concrete is a very nice option for a nice modern look for an outside patio.

If you have a old concrete patio that needs to be renovated give us a call at (210) 422-6116. Even if you think your concrete patio is in the worst condition we will come out for free and give you are input.

Before Grouting & Polishing Concrete

Polished Concrete

Polished Concrete

 

 

 

Stopping Concrete Efflorescence

Concrete efflorescence is a white powder that is is found on the concrete surface. It is caused by the water from underneath the concrete migrating up the slab, once it reaches the top, the water will evaporate and leave salt particles on the surface. The white efflorescence powder will be soft at first but eventually will turn hard.

Efflorescence On Concrete

Efflorescence On Concrete

If the efflorescence is left on the concrete for long periods of time it will eventually start to eat into the concrete leaving the concrete with a lot of divots and pits as you can see in the photo below. The concrete will then have to be repaired.

Concrete With Moisture Problems

Concrete With Moisture Problems

There are two types of sealers we have used that have stopped efflorescence. One type is an epoxy vapor solve product that will basically seal off the concrete completely not allowing the water to escape. This product is best used if you are going to be putting another type of flooring on-top of the concrete that is not breathable such as laminate flooring, VCT, or wood. The epoxy coating can also be used if you want to clean up the look of the concrete if it is going to be left alone. Applying concrete coatings is best left to the professionals because of the proper surface profile needed for the coating to bond properly.

Concrete Epoxy Coating

Concrete Epoxy Coating

The other type of sealer we have used is a cost affective DIY alternative to the epoxy vapor solve product. It is a penetrating sealer that will not change the look of the concrete and will still allow the water to pass through the slab. It is not used if you are trying to completely eliminate the moisture coming through the slab. This type of sealer will only stop the efflorescence from forming. It can be used on concrete and bricks.  The concrete will need to be cleaned and all of the efflorescence removed from the surface before applying the sealer.

The pictures above are of a garage floor that had serious moisture problems. Water was seeping through the concrete pooling in the middle of the garage. Efflorescence was starting to form causing the concrete to pit. We were called to restore the concrete; we prepped the surface and then applied a tinted vapor solve epoxy system followed by a top coat of polyurethane.

Restoring Concrete To Its Original Look

Restoring concrete to its original look can be effectively and efficiently achieved by pressure washing the surface. Over time concrete will absorb oils, mildew will start to grow on the surface, and black grime will get imbedded into the pores. Pressure washing will remove these contaminants by using significant pressure to blast away the dirt and mildew.

When you are using a pressure washer to restore concrete, you must make sure the concrete will not get damaged when pressure washing.  Concrete that is flaking or is weak will be etched by the pressure, this will create an unpleasant look. When the concrete is not in good condition to use a high PSI pressure washer,  you must use detergents to restore the concrete.