Thursday, February 16, 2012
Tuesday, February 14, 2012
Okay when it comes to concrete on driveways a majority of contractors,(even good contractors),have been led to believe that prep for concrete is not that big an issue as with asphalt. THIS IS NOT THE CASE. Have you ever seen concrete driveways/parkinglots cracked? I know you have ,especially cracks that one side of the crack appears to be higher or lower than the other. This is the tell-tale sign of poor prep and or compaction. Where most think concrete is stronger than asphalt asphalt is "pliable". Concrete is not,it is very brittle and under its own weight will create "settling in un-compacted or soft subgrade or base."Due to the extreme difficulty and cost of repairing concrete it is very important to expect any contractor doing work for you to follow the same specs as asphalt.. When the begin to argue their point with you,(and they will),don't back down.unless you want a driveway that will not stand the test of time,or you have money to burn and like having a demo saw and jack-hammer defoning the neighborhood. I have, unfortunately,repaired more of these "pour on dirt"and "an inch of #57 stone " jobs than I would ever want. Wire re-enforcing is also a must,without wire or steel"rebar"re-enforcing you are simply wasting your time and money. If you don't believe me I'm sure it will not take you long to find someone in your area that will tell you they wish that they had been educated on the subject before they had their job done. Myself personally I prefer asphalt to concrete anyway due to concrete's blinding reflection in sunlight,it's really hard on automotive tires,tends to hold water more often,does not flex if you scrub your toe on the highly abrasive brushed surface. and is very difficult and expensive to repair. Anyway in my next post we will get deeper into the do's and don'ts
Tuesday, February 7, 2012
Ok,I was absent for some time as I've had so much going on but let's continue.
For those who have an asphalt drive already and it has begun to crack or rut out or pot holes have appeared,give a few contractors a call to come give an estimate on "overlaying your drive. If you drive has little or no structural damage a straight forward over lay is what you need. I recommend 1.5 - 2 inches of a 9.5 mm or"f" mix.If it's rutting or cracking or has mud pumping up through the top you need some corrective work first. Anything soft or muddy,seems wet or is rutting and you can see it move when traffic rolls across it should be saw cut and removed down to solid subgrade and replaced with GAB and or 19 mm asphalt and compacted. Then leveled by zeroing the depth cranks on the paver. Bituminous asphaltic "Tack" coat should be applied(liquid asphalt,ac3). If the contractor is a reputable one they will recommend this. After the "tack coat" an anti-fracture membrane called"petro-mat" will be rolled out. This is a type of fabric that is soaked and coated with asphalt. Then the top coat or overlay. This fabric may cost a little more but it is well worth the cost. It will prevent cracking and failure in the existing asphalt from coming to the surface through the new over lay. This is one of the most important if not the most important step to take in overlaying existing asphalt. It will provide an element of re-enforcement preventing any failure to come through the new paving job,as well as a moisture barrier. Again make sure you speak with your contractor about water drainage. Pay close attention to any walk ways, carports,doorways,garages making certain you have room for additional material without damming water or throwing water back inside the house or carport.It may be necessary to saw cut and remove existing material far enough away from the set grade(doorway,steps,carport) to apply the new lift of asphalt without holding water. Be sure once the paving has been completed that any waste material is picked up and removed as the paving crew leaves. Once it loses temp it will be solid and ,depending on the amount,could be very hard for the home owner to deal with. Look the drive/parking lot over for roller marks, splits, or cracks while the contractor is cleaning up and loading equipment. If there is any problems this is the best time to correct them. Most "good"paving foremen will walk the job over taking a final look before picking up and leaving. I always unrolled the water hose and wet the job to check for proper drainage. Dont try to do this until the finish roller has completed marking out .In my next post we will look at cementitious concrete on driveways/small parking areas.
For those who have an asphalt drive already and it has begun to crack or rut out or pot holes have appeared,give a few contractors a call to come give an estimate on "overlaying your drive. If you drive has little or no structural damage a straight forward over lay is what you need. I recommend 1.5 - 2 inches of a 9.5 mm or"f" mix.If it's rutting or cracking or has mud pumping up through the top you need some corrective work first. Anything soft or muddy,seems wet or is rutting and you can see it move when traffic rolls across it should be saw cut and removed down to solid subgrade and replaced with GAB and or 19 mm asphalt and compacted. Then leveled by zeroing the depth cranks on the paver. Bituminous asphaltic "Tack" coat should be applied(liquid asphalt,ac3). If the contractor is a reputable one they will recommend this. After the "tack coat" an anti-fracture membrane called"petro-mat" will be rolled out. This is a type of fabric that is soaked and coated with asphalt. Then the top coat or overlay. This fabric may cost a little more but it is well worth the cost. It will prevent cracking and failure in the existing asphalt from coming to the surface through the new over lay. This is one of the most important if not the most important step to take in overlaying existing asphalt. It will provide an element of re-enforcement preventing any failure to come through the new paving job,as well as a moisture barrier. Again make sure you speak with your contractor about water drainage. Pay close attention to any walk ways, carports,doorways,garages making certain you have room for additional material without damming water or throwing water back inside the house or carport.It may be necessary to saw cut and remove existing material far enough away from the set grade(doorway,steps,carport) to apply the new lift of asphalt without holding water. Be sure once the paving has been completed that any waste material is picked up and removed as the paving crew leaves. Once it loses temp it will be solid and ,depending on the amount,could be very hard for the home owner to deal with. Look the drive/parking lot over for roller marks, splits, or cracks while the contractor is cleaning up and loading equipment. If there is any problems this is the best time to correct them. Most "good"paving foremen will walk the job over taking a final look before picking up and leaving. I always unrolled the water hose and wet the job to check for proper drainage. Dont try to do this until the finish roller has completed marking out .In my next post we will look at cementitious concrete on driveways/small parking areas.
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