Home addition question about existing foundation

[moss2940]

I was curious how or if this could be accomplished?
My house has a breezeway between the house and garage. The house, breezeway and garage are all on the same concrete foundation.
The concrete where the breezeway is, has a slight slope to it.
What is the best method for leveling something like this? Is it even possible?
The breezeway is about 26' x 15'. The slight slope is over the 26' direction and drops maybe 1.5-2"'s over the length of the 26' part.

Thanks Randy

 

[goaliedad]

In our area there is a company that advertises that they will level slabs- I think they inject concrete under the slab.

What are you trying to do? are you going to finish the breezeway to make it a useable room? If so, do you have the option of framing a wooden floor over the slab- maybe put some foam board insulation in while you're at it?

good luck

 

[EddieWalker]

Randy,

The expensive and dificult way would be to cut out the old stuff and pour a new one. Depending on your local code and what you plan to do, you might have to cut it out.

If the pad is strong enough to support what you want to build, then the easiest and cheapest method is to build up the low end.

Cutting down the high end isn't an option due to the structural damage it will cause. 2 inches is way too much to take out. If it was just half an inch, I say cut it down, but don't even think about it on your application.

But it all really depends on what you plan to do and how the breezeway was poured. My experience with something like that is it was probably just a walkway without any footers on the ends. There would be no reason to go to the expense in pour footings in the initial construction, so it's very doubtful you could build anyting on the existing concrete anyway.

Dig down along the sides and see how thick it is. This will tell you more about what you have to work with. I'd also be suprised if it really was one solid pour. My guess is that closer inspection will reveal the seams. Maybe under the door sill, but I'm guessing it's there.

Eddie

 

[moss2940]

I was afraid I would mess up trying to describe it.
Let me take a picture of it tomorrow and I will put it in the post and it will probably be easier to help me figure out what I should do.
Thanks for the replies so far,
Randy

 

[MossRoad]

Do you think it is sloped on purpose for water runoff or it has sunk over the years?

 

[neilly2]

To answer your question -- yes you can level it.

Now, you wrote House addition in you title, but you didn't say if you were enclosing this breezeway, making it livable interior space, or if it would stay exposed to the elements.

There is concrete floor leveler, brand name Ardex, that will level it perfectly, it self levels and will taper down to nothing to blend into the high side. You would just have to put a small 2x form along the two low sides and have at it. I have only done this for interior applications, I don't know if they have something for exterior. Also, you would want to cover it, as it will look like a patch. Carpet or tile, etc.

I doubt highly you would have to remove your slab, if you are using it only to support a roof load. Assuming this is old, it has settled as far as it will ever settle. But, there are a host of other considerations --- is the concrete spalling anywhere, any exposed rebar, is it less than 3.5" thick, etc.

P.S. Though the Ardex is technically a patch it will last as long as the concrete.

 

[bugstruck]

Ardex makes exterior patch materials, but I'm not aware of it being used in exterior applications, like the interior leveling coats. That would be a check with the manufacturer. It's not cheap. I think this breezeway becomes interior space though.

The roof is already there, self supporting, and tied into the house and garage that are frost heave controlled, I assume. The 2" over 26' of slope is maybe, barely humanly perceptible as out of level, exept for some alignment (visual) issues or if you drop a large ball on the hard floor and watch it roll. I don't know where from he hails, but if it's frost area and that slab is tied in, then that slab should be frost controlled. The pictures may tell something on that. Only by excavating a small area next to the slab could one be certain it has frost footers.

If that is the scenario, I'd frame it up, level the slab with a top coat (only if was bothersome), and go on with it. If it's not frost controlled he can't frame it until it is. Otherwise, the slab will heave and make a big mess against that locked-in roof framing. All this assumes he freezes, he may not.

HTH

 

[CurlyDave]

The slight slope is over the 26' direction and drops maybe 1.5-2"'s over the length of the 26' part.

How did you even notice this slope? To me, that is in the almost unnoticable range.

If you plan to frame in the area no one will ever know, if it is carpeted. If you use tile or linoleum marbles and the like may roll to one end, but I am not certain even that would happen.

If you are planning to convert the breezeway to a room you need to check your local codes. In many areas it is not legal to have a garage be on the same level as habitable space and have a door into the garage. The reason for this is that gasoline vapors from a car can enter the house through the door. In most areas, if there is a garage attached to a house, the garage must be ~18" below the house level. Gasoline vapors are heaver than air and this keeps them out of the house.

Just about the only way to have a garage on the same level as the house is to separate them with a breezeway like you have.

All of the houses in CA are built this way. 2 or 3 steps up from the garage to the house, a detached garage, or a breezeway. We bought land, and are building in OR. I talked to a local builder & he didn't think there was a code about this in OR, but even if there isn't, it is still a bad practice to allow the possibility of gas fumes entering the living area.

 

[tlbuser]

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If you are planning to convert the breezeway to a room you need to check your local codes. In many areas it is not legal to have a garage be on the same level as habitable space and have a door into the garage. The reason for this is that gasoline vapors from a car can enter the house through the door. In most areas, if there is a garage attached to a house, the garage must be ~18" below the house level. Gasoline vapors are heaver than air and this keeps them out of the house.

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Agree with what your saying, but we have a 4" minimum vertical separation.

 

[moss2940]

Thanks for the responses so far.
Here is a photo of the area I was talking about. It is one solid foundation. This is the area between the house and the garage. The foundation has not sunk, it was built with a slope for drainage.
The next photo will show how much it slopes.