New project-existing slab question

[texman]

Hey everybody

This is my first post. I have attached a picture of my site for the new kitchen and pizza oven. The blue tape in the pic is the rough outline of the kitchen counters and a corner oven.

The existing slab has about 3" of fall to deal with. My thinking is that I would pour concrete on top of the existing slab to level the areas for the oven base and counter footprints. I am estimating 50 ish bags of sacrete. So I am wondering if there is a better way.

I also plan to cover the area since it is next to house and gets roof runoff into the area.
Please give me comments, suggestions, advice and encouragement

[Millstone Man]

Re: New project-existing slab question

Welcome aboard texman. You could just cut your brick/block to get it square and level and leave your pitch for drainage as you will still need it. A little more work on the cutting but less than pouring 50 bags of concrete. You would want to make sure all the water has a way off the patio.

If you decide to pour an overcoat, look into a mix that is designed for overlaying on existing concrete and use a bonding agent to get it to stick better. Good luck and welcome from a fellow Texan. - Scott

[Les]

Re: New project-existing slab question

You could just cut your brick/block to get it square and level and leave your pitch for drainage as you will still need it.

Agreed. My thought was to rip the bottom course of block to get level. After I looked at your situation, you may get back to grade by using larger mortar joints on the fall side. Either approach you take, I would not pour concrete to get a level surface - it's not required here.

Welcome to the obsession - it's a great time.

Les...

[fxpose]

Re: New project-existing slab question

Nothing to add here but that's a great looking corner for your oven and kitchen.

[GianniFocaccia]

Re: New project-existing slab question

Tex,

Welcome! Looks like a great project, and I love the curved counter.

Have you considered covering the patio first? It appears that any runoff might collect and pool around the inside of your counter, and the shade benefits of a cover goes a long way, not to mention the advantage of lights for night work.

Looking forward to seeing your project take shape.

John

[texman]

Re: New project-existing slab question

thanks for the advice. Cutting bricks sounds much better than sacrete.
I have looked at numerous projects here. Some dry stack the blocks and then fill the cells, some mortar the joints as they build. Are both acceptable?
also, should i start the block laying at the lowest point and cut the blocks as i work up the slab? i.e. use a full block at the lowest point and then cut from there? probably doesnt really matter i think.

How about the rebar reinforcment? should i just drill the existing slab and mortar the vertical rebar? every two feet?

[dmun]

Re: New project-existing slab question

I have looked at numerous projects here. Some dry stack the blocks and then fill the cells, some mortar the joints as they build. Are both acceptable?

Dry stacking is easy. If you have no prior block laying experience do it that way. I mortared up a bunch of block and it took till the end of the project before half my mortar didn't end up down the block cavities. If you are comfortable laying block, than by all means go for it.

should i start the block laying at the lowest point and cut the blocks as i work up the slab? i.e. use a full block at the lowest point and then cut from there? probably doesnt really matter i think.

Right you are. Either way, or split the difference should work fine.

How about the rebar reinforcment? should i just drill the existing slab and mortar the vertical rebar? every two feet?

I really don't think you need to do this unless you are in an earthquake zone. Everyone else just stacked, and filled every second or third cell stack. On the other hand there's nothing wrong with tying your slabs to your stand. This one will work either way.

As you are perhaps learning, there is a lot of leeway on this project.

[texman]

Re: New project-existing slab question

Thanks dmun
got my electrical extended today. i had an old 220v dryer disconnect that is not being used. So that is my electrical for the new kitchen. I split it to two 110v circuits and am adding a ground rod just to be safe. Hopefully add a hot water hosebib for the sink tomorrow. Trying to get the utility stuff ready before starting the blocks.
Is there any reason that the block should be against the existing brick of the house?
I planned to run the electric in conduit and a gas line for grill in a 1" gap between block and existing brick. I am thinking the coutertops will either be flagstone or concrete which will hide the gap between block and brick wall. Any problems there?

[Les]

Re: New project-existing slab question

Is there any reason that the block should be against the existing brick of the house?

Not at all - they are all pretty much free standing.

Les...

[Neil2]

Re: New project-existing slab question

If you are building on an existing slab, you may want to consider a construction joint around the perimeter of the new works.

The additional weight will cause some settlement. This settlement may be slight but will almost certainly cause cracking in the slab. The construction joint will control where the cracking occurs.

You can form the joint by using a straight edge and a thin cutting wheel on an angle grinder. For concrete, cut about 1/4 to 1/2 inch deep.

[texman]

Re: New project-existing slab question

If you are building on an existing slab, you may want to consider a construction joint around the perimeter of the new works.

The additional weight will cause some settlement. This settlement may be slight but will almost certainly cause cracking in the slab. The construction joint will control where the cracking occurs.

You can form the joint by using a straight edge and a thin cutting wheel on an angle grinder. For concrete, cut about 1/4 to 1/2 inch deep.

Neil2
Should I add the construction joint just around wfo base? or around the areas where the block foundation will be for the counter/cabinet as well. I am planning on flagstone of concrete for counter tops-so wil add some weight.

[texman]

Re: New project-existing slab question

seeing if my signature works-sorry

[Neil2]

Re: New project-existing slab question

"Should I add the construction joint just around wfo base? or around the areas where the block foundation will be for the counter/cabinet as well."

For the amount of time involved, you may as well put it around everything. It is difficult to control slab cracking, you may also get cracks radiating out at a a 45 degree angle from the outside corners of your new works.

[texman]

Re: New project-existing slab question

Tex,

Welcome! Looks like a great project, and I love the curved counter.

Have you considered covering the patio first? It appears that any runoff might collect and pool around the inside of your counter, and the shade benefits of a cover goes a long way, not to mention the advantage of lights for night work.

Looking forward to seeing your project take shape.

John

Trying to figure ou the best materials/method for the curved counters. I am thinking metal stud/hardibacker is best? But the backer is rigid. Do you kerf the backer board to give it some flex or is there another material?

[GianniFocaccia]

Re: New project-existing slab question

Tex,

I am not qualified to advise on this, although I believe I have seen a few builds that do it the way you have described: metals studs, hardibacker and whatever cladding you desire - stucco, tile, brick. I know Breven on this site did a curved oven stand out of cocncrete block that he covered in brick that came out wonderfully. You can also check out some builds here:

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John