When they installed my basement floor they cut the floor with a saw to allow the concrete to crack on a planned path. (they say concrete always cracks).
It often does (and sadly not always on the saw cuts either).
At any rate, I plan to put down an epoxy floor ... leaning to a water based since its in a basement.
There is no reason to use a water based coating in a basement. Today water is added to epoxy for primarily one technical advantage... profit.
However, should I put a caulk in the crack? Or just leave the cracks open?
This is mostly an aesthetic call; many people just like the look of a completely smooth, floor. A look known as a "Brazilian Floor."
A vast monolithic expanse of glossy floor does look pretty sharp, but there are some practical advantages...
- Grooves and cracks catch dirt and debris.
- Grooves and cracks make it more difficult to roll jacks, engine hoists, tool carts etc.
- Grooves and cracks have exposed edges which can be chipped or gouged.
- Grooves and cracks can allow liquid to seep in and under the slab. Under some conditions that could cause problems with the floor.
...seems if i fill them the epoxy will crack in time on top of it.
Cheap fillers might get brittle and crack, or might shrink and crack over time, but if the slab is static there's no reason why a
quality filler would ever crack.
The problem is that concrete slabs do shift over time. Thaw/freeze cycles, seismic activity, settling, impacts, shifting weight of cars etc., things just move.
The solution is to use a filler that is flexible. There are epoxy products that do retain a level of flexibility after they're fully cured, and they can be coated over with epoxies and other floor coatings. Many coating companies have fillers compatible with their coatings. In our case we offer IntegraFlex 1921.
IntegraFlex 1921 is a 100% solids, two-component polymer hybrid resilient filler for expansion joints and cracks in concrete or masonry. When cured IntegraFlex 1921 is extremely durable yet retains excellent flexibility (up to 50% elongation at 70˚f), it is self priming, and provides exceptional adhesion characteristics. IntegraFlex 1921 is recommended for expansion joints in general industry as well as expansion joints of garages, highways, bridges, driveways, sidewalks, and marine decks. For vertical or overhead joints and cracks we offer IntegraFlex 1922. Both IntegraFlex 1921 & 1922 provide an excellent bonding surface for other Wolverine Coatings Corporation products like BondTite 1101. A one gallon kit will fill approximately 165 cubic inches.
IntegraFlex used for both cracks & expansion joints, coated with BondTite 1101 epoxy primer:
