Thread: Slanted workshop floor

The crucial question is: using the corner that is highest, how much fall (slope) to the other 3 corners and is there a hump in the middle?

Under those circumstances I'd just level the machinery rather than try to fix the floor. Make bases with adjustable feet.

hard to determine because of shelving machinery etc. there is fall on the slab away from the house (Naturally) and towards the rear of the house which is fine. the back outside corner is about 120mm lower over 2.5m so that corners a bit much. no hump.
My biggest concern is about standing on an uneven surface for extended periods and the back issues etc that come with that.

Is the slab exposed to weather or subject to water run-off passing through?

If it's fairly well protected you could just mark out some parallel straight lines on the slab, about 600mm apart and then use a laser/water-level from the highest point of the slab to every 20mm or so along the lines to map out the contours. (hint: Write the measurements in pencil directly on the slab at the points measured to save confusion.) Rip some joists to suit those measurements and lay yellow-tongue on top.

I'd aim to have the top of joists about 60mm higher than the highest point (to cater for nails/screws/whetever while only raising the floor <100mm total with yellow-tongue on top) and either use packers underneath at the low ends or do the same thing to scribe in some bearers (more cost, better durability) about 900mm apart where needed.

Far from a permanent solution - which is not necessarily a bad thing in a rental - but it's about as cheap as you can expect to get away with and still support the weight of WW machinery.

I used to work in an exposed carport area 9x7m that had a decent slope to it. I never really had any issues with anything. I did install a spoon drain, though, as in high rain I did have issues with water but that was an easy fix. I never noticed much on my back. It was noticeable on the table saw when I would move it around and so on. It's a rental. I wouldn't go crazy.

Set up perimeter formwork to a level line, 1.8 cubic meters concrete, black plastic over the existing first, dont bother with steel reinforcement.
Waterproof, level, cheaper than stuffing around with timber and flooring. Hire a mixer from the nearest plant hire, 3 metal, 2 sand, 1 cement = 1 cu m metal 0.6 cu m sand 0.3 cu m cement all available at landscape supplies.

When I laid the the concrete floor in my old 5.2 x 3.6 shed back in 1980 I did not properly compact it so over 20 years it sank about 75mm! in one corner and a crack developed through the middle across the 5.3m length and the same side with the corner dropped about 25 mm. As I increasing spent more time in the shed I didn't notice this although I wasn't working in the dropped corner which was occupied by a bench. When I started buying machinery I just I filled the cracks with cement and levelled each machine by adding custom feet. In 2011 I built a new shed attached to the old one and replaced the floor so that it matched levels with the new shed.