Garage concrete and driveway asphalt repairs

creamaster

We have multiple cracks and upheaval in the garage floor at the garage door entrance due to water from the gutter that wasnt drained far enough from the house and it back flowed to the corner foundation block of the garage. Also the asphalt along the garage door is crumbling away. I plan to jack hammer out the damaged concrete and asphalt and have a few questions you folks might be able to help with:

1. What type of concrete should I use to repair the damaged stuff I take out, roughly 15 sq foot is going to be repaired?
2. What is the minimum thickness that I should pour the concrete?
3. Is gravel used as a foundation to pour the concrete and ashpalt repair? If yes is there any particular type I should use?
4. Should the concrete floor and the asphalt driveway be the same height where they meet at the garage door entrance?
5. There is a 3-4 inch sized hole if you will in the ground level foundation block at the very outer corner where the gutter water back drained into and caused. Would a mortar type mix be sufficent to repair this hole?
6.Where the ashpalt comes in contact with the block foundation for the garage/house should a type of sealant be used or should I ramp up the ashpalt an inch or 2 to help with drainig any water away?
7. Can the repaired asphalt that I tamp in be sealed right away or is there a time delay before sealing?
8. Where the newly poured concrete meets the existing concrete, is there any particular prep work to do or solvent to use for better adhesion of the 2 concretes and to reduce chance for future cracking at this juncture?

Thanks for any help you folks can offer.

Termite

1) for a garage floor, go with a fairly strong mix. You can buy the quickrete with extra compressive strength over the regular yellow bag stuff. The regular stuff would work fine. Just don't make it soupy. Just enough water to finish it. Excess water makes for weak concrete.

2) 6"

3) Yes, use gravel. Basic 1/2" or 3/4" clean gravel is fine.

4) I see this done two ways. You can pour them the same height or make the garage slab a tad bit higher to keep water from seeping in. Depends on the slope of things at your house.

5) Hard to tell what the hole is based on your description. It might have been intended to let water out from under the garage. Be sure you know what it is for before plugging it. Use hydraulic cement if you want it water tight. Basic mortar/concrete won't be watertight.

6) I would not suggest a sealant. It won't be watertight. You need to slope the asphalt to encourage water to flow away from the house. A slight curb would probably do the trick.

7) Cold patch can be sealed immediately. If you were using hot patch it would need to set up for a little while. I'm not an asphalt pro, so hopefully one will chime in.

8) Where the concrete meets, plan on it cracking. There is NO WAY to properly bond the old and new concrete together to prevent a crack. You need to drill in some rebar into the old concrete and pour the new concrete around it. That will structurally tie the two pours together. It is a cold joint, so it will probably eventually show a crack. How big that crack gets is up to you and how much rebar you put in, and how well you compact the subgrade. The more rebar the better. Keep it 2" down from the top and 2" up from the bottom at least. I'd drill a good 5-6" deep into the existing concrete, and would use concrete epoxy to bond the bar. Be sure to blow the dust from the drilled hole first. Also be sure to run rebar both ways in the new portion of the slab. I'd suggest 12" on center each way.

kbrena

Hello. thekctermite has given you excellent advice. As for the asphalt, it is difficult for the home owner to get hot asphalt. They will sell it to you but most asphalt plants have a 1 ton minimum. That is the case in my area anyway. It will also make a real mess of your truck. One way to protect your truck is to cover your bed with a plywood bottom and sides then spray the plywood with diesel. Make sure you tell the plant operator to drop the loads in 2-3 drops because the shoot is about 12' in the air. You will also need to buy a product called "TAC" (pronounced like tack) and a tac broom to spread it. You coat all the sides around the patch. The tac will create a bond to the existing asphalt or concrete. The base prep will be the same as thectermite was describing for the concrete, minus the re-bar. Your existing driveway is probably 4", so I would replace with whatever that thickness is. Do not fill the patch all the way to the top, fill and compact in 2" increments.

As you can see there is much more work involved with using hot compared to cold patch. For a cold patch repair... You could go to home Depot and buy bags of it and do it that way. you will not need tac. I would suggest getting some sealer (comes in a caulking tube) that is for repairing cracks in a driveway and put a bead around the perimeter and squeegee it into the crack were the new patch meets the old. Do this before you seal. As far as sealing it immediately, diesel is added to the asphalt to keep it from hardening quick like hot asphalt. So you would want the diesel to have a chance to evaporate out some-what before sealing. So depending on your weather, it shouldn't be too long. One way to check is to lay your hand flat over the patch and see if there is much pick-up when you pull it away. Building up the edges like you were describing would be just what you should do. Good luck.

Kelly

creamaster

Thanks for the advise thus far! A couple more questions though:

The rebar? Can this be purchased at Lowes/HD, if so what size sould I use?

As for framing in the concrete pour, would plywood or fir 2x8's work? Will the concrete adhere to the framing wood?

The hole in the foundation corner block is definately not supposed to be there, it is more like a hole/crack that has formed from water intrusion. Just wondering if mortar or concrete mix should be used to fix it?

I plan on using cold patch for the asphalt repair, what type of caulking should I use for the perimeter, where old meets new, that you are mentioning?

Thanks again!

kbrena

yes you can by rebar at Home Depot. As far as the size, I am not positive but I would imagine 1/4" or 1/2" would be good. I usually use 2x4 or 2x6 material for forms because there so rigid. You can spray diesel on the wood to keep the concrete from sticking.

For the hole, there are a lot of products out there. I have used a product at work called Seka-plug (not sure if spelled right) for plugging cracks/gaps in storm manholes. It cures very quickly and can even be used while water is running through. Ask at Hardware store, they have similar products.

The crack sealer, I have seen it at Home Depot In the area where you get caulking. I have not used the caulking crack sealer but I'm sure it would be fine. I'm sure it's just made to be convenient for home owners. I am mostly familiar of a hot product called AR-4000 that we use at work. You would need to go to an asphalt plant to find it, so I'm not sure if it would be worth it to you. good luck

Kelly