wobblycogs
Established Member
FFL = Finished Floor Level (http://www.acronymfinder.com can be very useful)
Shuttering is temporary boarding that you use to define the shape of the concrete while it's being poured / settting. The shuttering can be fairly rough and ready because it's only used once but it has to be strong enough to hold back the weight of the wet concrete without moving.
Imagine you wanted to make a 300mm thick concrete slab out in the back garden (I'm pretenting it's going to just sit on the ground). Build an open bottomed box of the correct dimentions such that the top edges are level (with a spirit level) and the shortest distance from the top of the shuttering to the ground is 300mm. Depending on how flat your ground is the sides of the box might be different heights but the top must be level as this defines the edges of your finished floor.
Flood that with box with wet concrete, vibrate it down to remove air, and then use a straight edge (a piece of wood) to level off the top. Since the top of your shuttering is at FFL you just need to run the straight edge along the top of the shuttering to ensure that the concrete is at the correct height and level. You might also like to trowel the surface before it sets to get a smoother finish. Level off will be easier with two people if the span is more than a couple of meters. Leveling the curve will be interesting.
BTW, I'm not a builder but I've done a few concrete bases over the years.
Shuttering is temporary boarding that you use to define the shape of the concrete while it's being poured / settting. The shuttering can be fairly rough and ready because it's only used once but it has to be strong enough to hold back the weight of the wet concrete without moving.
Imagine you wanted to make a 300mm thick concrete slab out in the back garden (I'm pretenting it's going to just sit on the ground). Build an open bottomed box of the correct dimentions such that the top edges are level (with a spirit level) and the shortest distance from the top of the shuttering to the ground is 300mm. Depending on how flat your ground is the sides of the box might be different heights but the top must be level as this defines the edges of your finished floor.
Flood that with box with wet concrete, vibrate it down to remove air, and then use a straight edge (a piece of wood) to level off the top. Since the top of your shuttering is at FFL you just need to run the straight edge along the top of the shuttering to ensure that the concrete is at the correct height and level. You might also like to trowel the surface before it sets to get a smoother finish. Level off will be easier with two people if the span is more than a couple of meters. Leveling the curve will be interesting.
BTW, I'm not a builder but I've done a few concrete bases over the years.
