Trimming a concrete slab

[bmwman91]

I worked at a Home Depot tool rental joint as a summer job back in college. They rent big industrial concrete scarifiers, or at least they did in 2003. It is exactly the tool you would be looking for in this case since its purpose is to grind concrete bumps down. IIRC, they rent a few sizes. Some are wheeled 600lb beasts, and others could probably be loaded into a pickup with 2 people. Call the local HD tool rental centers and see what they have.

[flyboyx]

as mentioned by f34r, the best way would be to cut out about 3 or 4 feet on each side of the lip, regrade and then re pour. however, he missed a few really important steps to actually make it last through the winter. first, and foremost: REBAR!!!! and driveway slab needs 1/2" rebar spaced in a checkerboard pattern at 1 foot intervals. second and also just as important: where the old slab joins the new slab, you need to drill holes in the edge about 5 inches deep so the rebar can slip in. this would pin the new concrete into the old slab so that it doesn't shift over time. Third: that root under the old concrete needs to be cut out of there. otherwise, in a short time, the driveway will start lifting again as the tree and corresponding root grow.


if you plan to be there for a few years, fix it right. if you are in school and only plan to live there a couple semesters, i say hillbilly engineer it.

the abrasive cut off saw in the craigslist ad is great. i own one of those and have used it on a handful of occasions such as this or when a drain pipe needs to be moved inside the kitchen/bathroom of a slab house. i don't think its worth spending 250 bucks on that tool if you only plan to use it once. it would be better to rent the tools you need to get the job done.

maybe you can work out a deal with the landlord where you and your buddies do the labor while the landlord pays for the materials and tool rentals? i think that would be your best bet.

[mrsleeve]

^

To add to this if you were to go that way you will need to pin the replacement pour to the existing and remove the offending root. By pinning I mean, you need to drill holes in the vertical face about 3-6 inches deep in the existing slab, ever 18-24 inches. Then you will need to drive in lengths of rebar , that is about 8-12 inches longer than the holes you have drilled. this will tie the new slab to the old slab and hold them together in the winter/spring time during the frost cycles

I still say your best bet is still get some masonry blades for your grinder and about an hour of your time

[CabbE30]

you guys are making this way too difficult. Go get a sledgehammer, some 2x4's, and some concrete. Put on your big boy pants, and bust out the raised area. You don't even have to do it all in one day. Chip away at it over the week and then frame and pour new concrete to match the slabs over the weekend. Done.

EDIT: Fill that hole and crack while you're at it.

[mrsleeve]

^

You do that in the north the 1st cycle of the seasons from winter to summer and that will be much worse that it is now frost heaves will make his car their bitch

[CabbE30]

^

You do that in the north the 1st cycle of the seasons from winter to summer and that will be much worse that it is now frost heaves will make his car their bitch

I had a feeling somebody would say something about that.
Pardon my ignorance, I just plastered the side of my house this weekend so I didn't think much of it.

[fronton]

Being that it is 4" thick, 7' wide and 4' feet long and without friends (as per Clarkson's observation), lifting the slab is not a viable option. Further it is likely connected to the lower broken half with rebar doubling its liftable mass.

As far as a sledge goes, as appealing to my destructive genes as that sounds, the slab will laugh at such attempts and the only damage incurred will be on my back and pride.

If it was my own house I'd have the entire driveway redone with asphalt. But it's not and I only need a 12-18 month bodge. If I can't get a pro to deal with it, I'll give the 4" grinder a shot. Am I supposed to grind it down from the top or cut through it from the side?

http://www.homedepot.com/p/RIDGID-4-...4#.UmVYGfnVD_U (grind from top) or
http://www.lowes.com/pd_178835-70-DW...1224261&rpp=32' (cut)

I am thinking both since and at least 3 of those blades.

[mrsleeve]

Get the masonry wheels and you start at 1 side and cut the top edge off if you were to try and grind it you would be there all month. Don't worry about making it perfect or look super great just make it function

[bmwman91]

Fronton, just go to a Home Depot with a rental center and rent a scarifier. It'll get the job done in 30 minutes and you won't need to get onto your hands & knees, probably for less than $100. I assume that your landlord is OK with this?

[LJ851]

/thread

[fronton]

Thanks for all the tips gents. It turned out that I needed to remove way more than just the top edge. I had a concrete guy cut out two feet of the top and bottom slabs in order to create a third plane effectively halving the original offending angle. No more scraping.

[Q5Quint]

Horay concrete guy!

My driveway will be needing this soon- the ice is turning it into a patchwork quilt of filled potholes.