I guess another good answer would be because they don't have a saw. Seriously, I would rather groove than cut because of the noise and dust and it is done before the concrete even thinks about setting up. I think we've all seen slabs that are cracked in the morning where they go around an inside corner.
1. Use the right mix without too much water - better concrete, but more grunt labor.
2. Saw late the same day when it is easy and fast with no dust. If it is warm it could be too late the next day. if you get there after 10:00 AM. the next day you might be too late, especially with a wet mix that loses water to the surface and the base. - If you saw, it is much cheaper, better and a more professional job and look that you can use as a reference.
Sawed control joints are more prone to spawling. There is a reason why some guys cut them in while finishing exterior work. But for interior nothing beats the look of a nice tight line from a saw. And by the way Pee Wee They are called control joints to try to control where the concrete cracks.
Tooled control joints (that's the name) are there to relieve the stress points and give concrete a place to crack.The old adage it gets hard and cracks is true,so we put them in to follow our way of thinking (crack here).Also if one pays attention the reason for tooled joints (exterior) is freeze thaw.Ever notice how the joint is V'd? When water freeze it expands,it allows the expanssion to move up.
Soft cutting is mostly used interior,most floors cover with something,not all.It makes for a nice clean looking floor,inside wharehouses and such.They are right about one thing,cut as soon as they can get on it.
Contractor Talk - Professional Construction and Remodeling Forum
A forum community dedicated to professional construction and remodeling contractors. Come join the discussion about the industry, trades, safety, projects, finishing, tools, machinery, styles, scales, reviews, accessories, classifieds, and more!