[Nick B]

We've been in our home for 13 years and have many cracks along the score lines. Overall, the concrete has done well with just a couple of cracks otherwise. I'd like to fix the score line cracks and it was suggested I fill the cracks with sand and then use an epoxy? caulk. As its not that easy to get on my hands and knees for hours at a timei I think that hiring someone to cut a groove with a diamond saw might be a good idea. In a couple of places, there are large grooves where a hard felt like material was filled in and it has worked very well.

Is there an easy and less expensive way to fix this problem? We are in an area where it can dip to below 20 degrees  a few times a year
Nick

[thunderbrick]

The score lines are their to "guide" the cracking to those points.  I wouldn't use a diamond saw to do any cutting.  If the cracks already exist I think the saw would be a waste of time. 

How deep/wide are they?  Do you even need to do anything at all?   

Sit on an automotive "creeper" or a wheeled stool and roll long to save your knees.

Edit:  That hard felt material sounds lime an expansion joint inserted during the original pour, not a repair.

[Big Red Machine]

In my last house I developed a crack that ran under 2 walls and was close to 20 feet long. I beveled the edges with a chisel to make more exposed gripping surface and filled the whole thing with hydraulic cement using a spatula. It pushes outward as it hardens and uses moisture to do so. Most cement repairman will use it in a basement application. You can buy it a HD I believe. Only took me a day to do this.  When it dried I painted over it with Drylock paint as it made me feel more comforted even though the concrete would easily overpower the paint.

[rollo]

  Nick do you have expansion joints every 20ft ? If not hire a qualified person to do so. Leave the cracks as is. patching just does not have longevity. Deja vu all over again.
   


charles

[Wayner]

Rain (or bad drainage) and frost are the two causes of cracks in your cement driveway. Unless you can stop the frost or rain, any repair will result in cracks again, only this time it might be somewhere less desirable.

I just replaced my driveway this summer (after 23 years) and the curse of northern climates will continue just like today (cold and snowing).

So, my advice is to let the cracks be.

'ner

[Nick B]

The scored areas are between 5 and 8' apart. The cracks are minimal, maybe 1/16" to an 1/8". The only joint that has the hard, felt-like material is close to the front door and is original. I live in So Utah and there really is no snow, but it can dip belong 20 in the winter. I had a neighbor tell me to fill in the cracks with epoxy so the cracks would not widen over time. I'll do the work so I don't have to see it get worse or spend significant repair money in 5-15 years down the road.

[Wayner]

Then I suspect that the base under the concrete has settled due to improper compaction before the cement was poured the first time, or rain water is getting underneath the concrete and has/is washing out the grade. I believe that repairing the cracks will result in them re-appearing in a short time. But, Nick, do as you see fit, its your concrete. I'm fussy about those things too, but sometimes, in the end, replacing is better then repairing.

Wayner

[thunderbrick]

The scored areas are between 5 and 8' apart. The cracks are minimal, maybe 1/16" to an 1/8". The only joint that has the hard, felt-like material is close to the front door and is original. I live in So Utah and there really is no snow, but it can dip belong 20 in the winter. I had a neighbor tell me to fill in the cracks with epoxy so the cracks would not widen over time. I'll do the work so I don't have to see it get worse or spend significant repair money in 5-15 years down the road.

I wouldn't do a thing.  If the concrete has settled and become uneven that's one thing, but 1/8th or 1/16th is nuttin'.   If there is evidence of wash it I might caulk it with driveway caulk, but I doubt you have that problem. 

That asphalt expansion joint is located exactly where it should be, as much a thermal break as anything.  It would make things worse if you diamond cut slots and inserted that expansion joint.  No benefit and much risk.   

[JLM]

Agree with T-brick, these cracks are of no consequence.  What you're describing are control joints that force a clean/unobtrusive crack when the concrete shrinks (as it does when it cures) or normal shifting/settling occurs.  The felt filler strip represents a construction joint, used to allow separate pours or differential settlement between a house resting on a deep foundation and a slab on grade ("dips into the 20's won't cause the ground to freeze which is what causes heaving). 

If you want to worry about something, worry about global warming, world hunger, or nuclear annihilation.

[Nick B]

Thanks, guys. I'll just leave it. Wasn't a big worry ......  Just trying to keep the homestead looking nice 

[mick wolfe]

Thanks, guys. I'll just leave it. Wasn't a big worry ......  Just trying to keep the homestead looking nice 

Leaving well enough alone isn't a bad option as most have suggested. Anytime I've attempted to patch concrete cracks, it's ended up looking worse and more noticeable than before. As already mentioned, I wouldn't get too excited unless some obvious settling or grade changes have occurred.

[jqp]

My understanding is that to avoid cracks your driveway or patio must be poured with a minimum of 4" of cement. This would be for NC, don't know about how northern temperatures would change this.

[Nick B]

I have at least 3 inches of concrete all around. It snows maybe one day a year here in So Utah ..... for which I am grateful

[JLM]

Yes 4 inches is the minimum recommended slab depth (to account for typical aggregate size).  Assuming a proper mix/depth of slab/working of the concrete the key to minimizing cracks is a proper base underneath the slab which includes good compaction and drainage.  In this case the control joints are doing exactly what they should and the minor cracking is to be expected.

As a structural engineer and former member of the American Concrete Institute allow me to properly define terms.  Cement is one ingredient of concrete - the powder to which water and aggregate (sand and gravel) is added to make concrete.  Strictly speaking concrete is pumped, shot, or placed but never poured.  Sorry, but this layman's terminology is driving me nuts.

[Nick B]

Thanks, JLM, for the "concrete" advice and clarification 

[ctviggen]

Yes 4 inches is the minimum recommended slab depth (to account for typical aggregate size).  Assuming a proper mix/depth of slab/working of the concrete the key to minimizing cracks is a proper base underneath the slab which includes good compaction and drainage.  In this case the control joints are doing exactly what they should and the minor cracking is to be expected.

As a structural engineer and former member of the American Concrete Institute allow me to properly define terms.  Cement is one ingredient of concrete - the powder to which water and aggregate (sand and gravel) is added to make concrete.  Strictly speaking concrete is pumped, shot, or placed but never poured.  Sorry, but this layman's terminology is driving me nuts.

I've never heard of concrete being pumped, shot, or placed, and have always heard it being poured.   I watch many home improvement shows, and concrete is always poured.  I'm not doubting your veracity, but there's "the way it should be" and "the way it is", and "the way it is" is completely dominating "the way it should be".  Perhaps it's best to give up?

Case in point, the "concrete network", where the article is entitled "POURING concrete": 

Step 4 - Placement

The sub base is compacted; the forms are set, now it's time for the concrete. The contractor has ordered a concrete mix that meets the requirements of the slab being placed. No matter where you live the minimum cement content for any residential concrete should be 470 lb. per yard of concrete, more for colder climates. If you live in a freeze thaw climate, a minimum of 4% of air entraining admixture should be used to help prevent scaling and spalling. Small stone can be used as aggregate in the concrete if it is going to be stamped, vs. regular ¾ inch stone for broom or smooth finish concrete slabs. The concrete will arrive in a ready mix concrete truck. The drum on the back of the truck will be spinning slowly to keep the concrete inside from settling and getting hard. The ready mix truck may be able to pull up to the site and pour right into the forms. If the site is on the other side of the house or building, the ready mix truck may pour into wheel barrows or a concrete pump to get the wet concrete to the site. The contractor and crew will pour wet concrete into the forms until they are full to the top edge. While the wet concrete is being poured, contractors will be using shovels, rakes and "come alongs" (special concrete rake) to move the concrete to make sure there are no voids or air pockets. Read more about placing concrete.

Now, this does discuss "placing" concrete, but to place it, you pour it. 

[thunderbrick]

Pour/place.  Stylus/needle.  Tube/valve.  Potato/potahto.   

[Tone Depth]

Hi JLM,

As a fellow engineer I'm with you! We state our professional opinion about something pertaining to our specialty, and lay persons don't accept it, because sometimes they rely on their limited experience to define their reality.

Yes 4 inches is the minimum recommended slab depth (to account for typical aggregate size).  Assuming a proper mix/depth of slab/working of the concrete the key to minimizing cracks is a proper base underneath the slab which includes good compaction and drainage.  In this case the control joints are doing exactly what they should and the minor cracking is to be expected.

As a structural engineer and former member of the American Concrete Institute allow me to properly define terms.  Cement is one ingredient of concrete - the powder to which water and aggregate (sand and gravel) is added to make concrete.  Strictly speaking concrete is pumped, shot, or placed but never poured.  Sorry, but this layman's terminology is driving me nuts.

[Bizarroterl]

I've never heard of concrete being pumped, shot, or placed, and have always heard it being poured.   I watch many home improvement shows, and concrete is always poured.  I'm not doubting your veracity, but there's "the way it should be" and "the way it is", and "the way it is" is completely dominating "the way it should be".  Perhaps it's best to give up?

Case in point, the "concrete network", where the article is entitled "POURING concrete": 

Now, this does discuss "placing" concrete, but to place it, you pour it.

Normally concrete is pumped when doing concrete walls and "shot" when making a swimming pool (as a couple examples).

[aldcoll]

I usually get a chair and maybe a cold beverage or two if the job looks big.  And if it's warm out I might seek out some shade.    I then make myself comfortable and most definitely make sure I am clear of all lanes of egress or access to the work area.   Lately this works best in my truck with either the AC or Heat adjusted, and if in the truck I crank up the tunes for the poor guys out there bustin their hump.

Once in my life we poured/pumped/dumped 1480 yards one day for a crew of 12.  And four of those guys stayed in their trucks.  And no Music.................................. .......