Uneven garage threshold

[thefultonhow]

Most of my garage is completely level. However, I have one section, right around the middle of the threshold, where the concrete is higher than the rest of the garage by about 0.5-1". There are no cracks, but as a result, the garage door does not seal at the bottom, and snowmelt and rainwater off of our cars pools in the middle of the garage.

My father-in-law, who used to be in construction, said it would be a bad idea to grind down the floor there, as it might become too thin and develop cracks. He suggested using self-leveling quick-dry mortar. I am hesitant to do this, as I would have to move everything out of the garage and put down a 1" layer over about 85% of the garage.

So, questions:

1. Is he right that grinding the floor down is a bad idea? (The house was built in 1985, so from my research, it's likely the floor is around 4.5" thick.)
2. Can I cut out the section where the floor is higher and repour concrete there? If so, what factors (rebar or mesh, gravel base, etc) should I take into consideration? And what ballpark $$$ would I be looking at in terms of material costs, tool rental, consumables for the tools, etc.?

Thanks!

 

[spotco2]

How large of an area would you have to grind down?

If it's only 1/2" or so it shouldn't be a problem. You would just have to decide if you wanted to do it by hand or rent a grinder.

 

[thefultonhow]

How large of an area would you have to grind down?

If it's only 1/2" or so it shouldn't be a problem. You would just have to decide if you wanted to do it by hand or rent a grinder.

My guess is around 20-30 sqft. I measured from the top of the doorframe and it looks like it will be a maximum of just over 1/2" if I want to get the threshold level (which is probably the priority). Not sure if it would be more to level the threshold with the middle of the garage.

By hand would probably be too much effort. I would rent a grinder if I do this.

 

[thefultonhow]

Does anyone else have a different perspective? I want to be able to say I got a few opinions and they all thought it was fine when I tell my father-in-law that I ignored his advice.

 

[Shea]

Grinding down 1/2" of concrete is a tremendous amount of work. Keep in mind that the floor is going to look different in that area as you will be exposing the aggregate in the concrete as you grind down through the surface.

 

[mikec35]

How good is your door seal? Is it compressed too much and worn out? Maybe a newer high density door seal or maybe you can slide a garden hose in on both sides of the door seal up until you reach the rise in the center. It may make your door gasket seal better in the lower parts of the floor.

 

[thefultonhow]

Grinding down 1/2" of concrete is a tremendous amount of work. Keep in mind that the floor is going to look different in that area as you will be exposing the aggregate in the concrete as you grind down through the surface.

I'm more worried about the structural integrity of the concrete. I don't want to develop cracks. I am fine with it looking different, as I have some plastic sheet type surface above it to aid in cleaning and draining. I'm also guessing the amount of work to grind the floor down is less than the amount of work it would take to either move everything out of the garage and build up the floor, or cut the offending section out and re-pour.

But, I am definitely not going to do this if the concrete will end up cracking. Hence why I am asking.

How good is your door seal? Is it compressed too much and worn out? Maybe a newer high density door seal or maybe you can slide a garden hose in on both sides of the door seal up until you reach the rise in the center. It may make your door gasket seal better in the lower parts of the floor.

Brand-new door seal, specifically designed for large uneven gaps. It's better than it was, but I can still see daylight on both sides, even though I have my garage door opener closing with such force that it bows up the opener's track when fully closed.

My goal is, along with a new insulated garage door and insulation along the wall not shared with the house, to be able to work on cars in there in the winter. This past winter, it got down to 25 degrees in there during the polar vortex. Normal temperature was 40 degrees or lower.

 

[n2ocamaro]

I have the same problem. Curious about everyone's feedback.

 

[Rookie2]

where is your floor drain ? i wouldn't worry about removing .5" of concrete ,it's 29 years old , have you ever tried to break up old concrete ? damn hard. You may want to get a quote from a contractor because renting a machine and trying it yourself is a 50/50 shot that you'll be happy.

 

[tncatadjuster]

I see no problem with grinding it down.

I doubt that if the concrete is not cracked now, that it would in the future unless it is overloaded. Cars would be safe on concrete that old and cured if 1/2" is thinner.

Look up and rent a EDCO turbo 7" or 10" grinder and be prepared to spend a lot of money on diamond cup wheels or segments, or call a contractor to bid it.

Any reason to not do just 1' wide the width of the door and then feather quickly.

Level away....

 

[Milton Shaw]

Drill a test hole to see the concrete thickness, if you are over 3.5 inches, go for it and grind away. It will take some time and might be better as said above to get a pro to do it. They should be able to leave it in better shape than trying to do it yourself with a rented grinder. Before they leave flood with water and see if there are any high/low spots to deal with.

 

[Fixnfly]

How about putting down a threshold?



http://www.homedepot.com/p/G-Floor-...ck-Door-Threshold-Trim-GFTHRESH16MB/203451252

 

[600SL]

I used something Like this for my garage in CT and it worked well. I will also be using it here in NC.

http://www.northshorecommercialdoor.com/16gadothkitb.html?gclid=COq_2ZLf5r8CFSdp7Aod8nAAUw