Split Level Concrete Patio – HOW?
MichaelJacob
| Posted in Construction Techniques on
I want to pour a split level concrete pation in my yard. total size is over 600sq feet. there will be a walkway, and small patio, then a single 6″ step up to the larger main seating area. How do i build a form for that ? the upper patio is 30×18. I’m a very visual person, so any online references or diagrams would be very helpful. I bought a couple concrete books, but none of them seem to address my needs.
i would also like to use a foam concrete bullnose form to edge the step, but thats secondary.
thanks for the help.
mike.
Replies
try visualizing this.
For the lower section you are going to use a 1 x 6 as the form , for the upper section you will use 2-1 x 6 as the forms. One stacked over the other verticly. Now imagine yourself shoveling gravel into the upper section that has the 2 -1 x 6's stacked until the gravel comes up to the seam between the two boards.
Now at the step go back and dig away about 1' of the gravel from the upper section step so that the concrete from the lower section flows under and merges with the the upper sections concrete.
I'd be most concerned about how you're planning to finish 600 SF of concrete, especially with a step to deal with- that'll be 10x harder than figuring out the formwork. I'm assuming you're DIY'ing this job, otherwise your contractor would handle the forming. Do you have a plan in place for getting all of that concrete finished properly before it sets up?
Bob
i'm covering it with stone. so it can look ugly.. :-)
View Image
I know, you wanted a patio, then the step. Sorry.
A is your standard 2x6 form, B is a sheet of 1/4" material. Grease it heavily where it contacts the lower concrete. After the 'crete cures for a week, strip A, then put a couple of C clamps on B and wiggle it out of there. Add enough water to 2 shovels of sand and 1 of cement to make a thick slurry, about like honey, and pour it in the groove left by the 1/4" stuff.
The dark brown speckly stuff under the slabs is well compacted 3/4 crusher run, a mix of all sizes broken rock from 3/4" down. See the dark grey speckles in the lower slab of the form detail? That's the crusher run you scrape out as you set the 2 piece form in place.
It is very important that you remove all topsoil under the slabs and replace it with compacted crusher run, sand, or, gravel, brought up to bottom of concrete.
You will want to cut a control joint in the middle of the 33' dimension. You will probable want to use some remesh or at least fiber mesh.
Concrete needs four Moist Weeks to completely cure to design strength.
When you set the rock face on the step riser, leave 1/4" clear under it. Caulk if you must.
About the dimensions of the thickened edge, the rule of thumb I use when it's not critical enough for an engineer's opinion is that the foot width is 1 1/2 times the slab thickness at the thickened edge. The run of the sloped bottom the the slab is 4 times the thickened edge thickness minus the slab thickness. A 3:12 slope.
SamT
Guys that don't do things correctly the first time.....then argue that they did nothing wrong.....if made to agree to fix the problem, rarely put the time and effort into truely doing it properly. they'll just look for the quickest fix to appease you and get their money. JDRHI 84310.51