Monday, January 26, 2015
Something's Cooking In The Kitchen
I suppose a more accurate title would be Something's Curing In The Kitchen, but this'll do! Unbelievably enough I finally got up the gumption to start pouring the first of the kitchen counter tops. We had a whole week of spring-like weather and I just couldn't let that pass without doing some kind of house work. A lot of times the hardest part of a project is simply starting, so I just took one step at a time and pretty soon it was going! The nice weather made getting and hauling the sand and gravel enjoyable and easy and that was one of the biggest steps.
Now, in this first photo you can see that I have everything pretty much ready and in the next photos I'll give you some detail shots and more explanations. As you can probably guess, the plastic sheeting is to protect my cabinets and also the stove that I left in place for the pour.
I ran my forms on grade, which is to say, I set the top of the form at the height I wanted my finished counter top. To me, it's just so much easier to finish to the top edge of the form rather than try to make a grade line and keep it visible while you are pouring. Of course, that's not that hard and what I had to do anyway on the sides that butted the backsplash area. When I get my forms set to the right elevation I always mark it with a crow's foot and that allows you to see if something happens to knock your form up or down.
I then leveled my grade line across the back and around the sides and was pleased to see that when I measured up 2" inches in random spots it actually hit the grade line! ha! I also partially ran a few long screws into a few studs to help "lock in" the counter top slab. It would probably never move on it's on but expansion and contraction and all that jazz, you know.
There are several ways to do the edge form and I choose again, just to clamp mine to my cabinets with a 1" spacer between the cabinet and the vertical form, which is the standard counter top overhang. Clamping does sometimes cause the form to roll out a little at the top but I'll show you how I remedied that in a minute.
The ends of the form were screwed off to available surfaces. I always use screws also because they are much easier to remove than nails and will not pull out like a nail will. Of course, there was very little pressure against this form but 2 inches of mud will exert a little.
This is looking at the inside of the edge form and you can see I caulked everything really good. The concrete mixture will weep way more than you might think so I always caulk any crack really well. A nice, smooth bead of CLEAR caulk in the bottom inside edge will give the bottom front edge of the concrete a really smooth finish too. I know everything looks white but this is that caulk that goes on white but dries to clear. The edge form and spacer are white though. To the left you can see the 3/4" plywood that tops my cabinets and is the bottom form for the counter tops.
The very last step is to put in your reinforcing and in this case I used dog wire. It's a 4"x2" grid wire. You could use chicken wire, hardware cloth or even #3 rebar. You also want your wire to end up about halfway up in the concrete rather than mashed down against the plywood. An easy way to do this is to initially pour a blob of mud about every 12 or 16" and then pull the wire back up so that it's about an inch off the bottom. I'm pouring 2" counter tops, btw. The mud will hold the wire in place then as you pour the rest.
We mixed the concrete outside and then just brought it in with buckets. I float the mud down as I go, pushing the concrete on grade towards the back first and working your way towards the front form. With floating you are kinda pushing and patting and smoothing. Not trying to get a smooth finish yet, just trying to get everything on grade. I also vibrate the edges with a palm sander and tap the underside of the form with a hammer to compact the mud. When bubbles stop coming to the surface you know you are done. Don't vibrate any more or you can actually separate your mix too much.
In this photo you can also see two other tricks. The side form against the stove is not nailed off as this was not possible without moving the stove and all that crap. I pushed the stove over to the left as much as I could and slid in the edge form. I then placed the wooden wedges every few inches and tapped them down until I got a good snug fit. Once it's screwed to the front edge form and caulked good it's not going anywhere. Always use wood wedges too because they won't scratch or dent anything.
You also see 2 wires running over the slab. I anchored 2 tapcons into the studs of that wall and then wired 2 little turnbuckles in the wiring, which ran over to the front edge form. As you tighten (or loosen) the turnbuckles you can move the form in or out, however you want. Works great. I simply used a straight edge on the front edge to determine when it was good. These are a tiny version of the large turnbuckles we use on big wall forms and such. After you pour and get it floated down, you want to check your lining again and make sure nothing moved.
Okay!! So, any questions?? I hope I explained all that correctly. If I didn't, please let me know and I can address it in the next posts. I'll do another on troweling the concrete for a good finish, removing the forms and all that.