Pro’s use knee boards and mag floats.
They also use a 2 x 4 or aluminum straight edge for control joints, or snap a string line.
Should’ve used 6 x 6 wire mesh instead of rebar.
Should’ve drilled pins into the edge of the existing slabs before the pour.
You don’t bull float like that.
Stone underneath the pad would’ve been nice.
Pro’s don’t usually need the truck driver to help.
All his tools looked virtually new. Seasoned pro I’m sure.
I have heard of this before (to prevent the new pad T.O.C. from changing) but I have heard a few others saying if a new pad is pinned to and existing pad/foundation and the pad wants to move, it will beginning cracking and could break. Not sure if I totally believe this though
Isn’t wood (or a metal form) only used to frame up new pads? I’ve seen this with sidewalks, they seem to knock the frame away once things begin to set up. Once that wood rots they should have a nice 2" gap between the pads. LOL
Not that I plan on doing concrete work but what would be the proper way to space those 2 pads out?
Actually, rebar mesh is preferred, and commonly used in commercial applications, but seems a bit overkill here. They should have used the existing concrete as the form and tossed an expansion joint in there. Standard practice is to drill dowels 2-4’ OC into the existing concrete to avoid heaving of the new slab. We do it all the time, except for old existing sidewalks because they will crack.
They probably watched a how to video and became “instant experts” like everyone likes to think they are when it comes to construction.
the main reason to pin a slab to another slab or to a foundation is to maintain the finished height of the new slab. in this case you wouldn’t want the new slab to move up or down significantly as it would create a change in elevation between new and existing. at an entry to a structure if the slab were to move up you might not be able to open the door properly.
on a technical note- none of these are expansion joints…concrete doesn’t expand. they are control joints to control the development of cracking in the slab.
BTW, what sizes holes should be drilled for pins? 1/2" re-bar so 5/8" hole? Do you put epoxy in the hole to hole the re-bar?
My neighbor has this new type of expansion joint in his driveway. I guess the new ones are rubber and last longer. My old expansion joint is that paper crap material that falls apart.
I typically use 1/2" for 1/2". Tap the pin in the hole. Don’t typically use epoxy for shear applications (where a pin is used to combat movement of two slabs or similar application). Others may disagree.