Screeding to fill holes in a workshop floor.

The concrete floor in my new (but old) workshop used to have baker's ovens bolted down to it, and they've left holes. In a room 15' x 25', there's about 6' square to fill, mostly in two large holes around 2" deep.

So what's my best option for some sort of screed to fill these in? Buy something (brandnames?) or mix it myself (proportions?)? What's the best technique for getting a reasonable flat finish afterwards.

The finished surface will have woodworking machinery in there, so the floor wil see "workshop" use, but I'm not going to be rolling steel- wheeled engine cranes or such across it all too often. It will be painted overall afterwards, but I can't afford epoxy.

I also need to trench something in to provide power feeds for a couple of centrally located machines. Any suggestions on how best to cable this? Trench with lid, or just bury a pipe with a drawrope and leave a big open access box at each end?

Thanks for any suggestions

Reply to
Andy Dingley
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Where do you live Andy - any where near Bury St Edmunds? I have some alu trench with ply lid going to waste in my shed which you are welcome to

Anna

Reply to
Anna Kettle

Assuming there's no damp, I'd just pva (4:1) the holes and use bags of B&Q general purpose mortar. After an hour or so, run a length of 2" x 1" across to get it level, and smooth with a wooden trowel. It held up well enough in my old workshop, although I tended not to move heavy equipment about that much. If there are feathered edges, I'd think about a 2 part latex screed.

Reply to
stuart noble

Nice workshop gloat. [/envy]

something (brandnames?) or mix it myself(proportions?)?

If it is 50mm or so, normal screed would be fine. 4:1 or 5:1 sharp sand:cement, in a pretty dry mix.

If the holes are well defined, tamping it down should end up pretty smooth, but it won't feather well if the holes kind of trail out. If that's the case then fill (most of) the holes with screed, let it set for a while, then float over the whole lot with a little self- levelling compound which will also give you a nice smooth surface (helping to sweep it, etc). You'll need to find a mix which can be used as a top surface though (rather than under a floor covering like lino, tile, etc) - try a few helplines (Ardex, Mapei, F Ball are a few names of many). Likely to be acrylic or waterbased, as the latex ones don't set as hard.

I'd go for the pipe/conduit, less to trip over (given that no floor covering is going over it).

If this is permanent, and you have the budget, I'd think about floating a ply or even chip floor over the concrete (assuming it is levell enough), but it would cost a bit more. More pleasant to work on and more friendly to the odd dropped tool. That way you could drop the SLC if you otherwise needed it.

Reply to
boltmail

power wash the surface, then hot water & soap ... to get rid of grease etc.

Etch the surface with floor acid (flooring supplies sell it) .... that gives it a good key ... and then pout over a self leveling polymer screed.

If you follow instructions for self leveling compound (spiked roller etc) you will have a perfectly flat and hard wearing surface.

I would cut trench using a 9" grinder with diamond blade, concrete in plastic conduit with draw string. If trench is shallow, put a steel mesh on top before you pout screed - protection only

Reply to
Rick Hughes

That's very kind of you, but I'm a long way away - right next to the Severn Bridge, Welsh side.

Reply to
Andy Dingley

This is just part of it 8-) One of the buildings - It's about 1,000 sq. ft. total.

(I am St*v* F*rth and you peasants aren't fit to pickle my eggs)

They're fairly square edged, or I can grind of a rebate out to not leave a feather. Last time I messed with screeds it was a too-thin layer of a self-levelling compound over a damp substrate and under tiles - not a successful result 8-(

That's a strong possibility for the adjoining building (it's an L- shape with a wide opening) where I plan to put the benches. Around the machines I think concrete should suffice.

Reply to
Andy Dingley

Gah, stop it.

Fair enough. Sounds like screed in the holes will do, unless you want to get a posher smoother surface with SLC - either way, some surface prep would be a good idea as Rick suggested, given the past usage (at least scabbling the holes or criss crossing them with a diamond blade to reveal some fresh concrete before you screed them). Don't PVA if the base is in any way damp - if it is and you want to prime use an SBR (but I'd just use a cement/water slurry).

Reply to
boltmail

An ordinary concrete mix will do fine. You can buy ready mixed aggregate and adding cement in a ratio of 1 to 6 will give you a medium strength mix which should be ok for a workshop floor. You'll be surprised how much you'll need though. About 0.2 cubic metres or 400kg of materials by my calculations. Slap it in and smooth over with a straight plank then you can run a float over it before it sets if you want the surface to be very smooth.

It'd be much easier to run the cable round the walls and across the roof and then down than go digging holes for it. You don't bollox an otherwise good floor just to get power feeds in to machines which may want to move at a later date anyway.

Reply to
Dave Baker

2" deep is enough for a concrete fill I'd say.

Dunno if this is best practcie, but Id use 2:1 sand:cement and shove a load of pea shingle in as well, then chip out the sides a bit irregular like, and maybe throw a sheet of chicken wire in the bottom ,and splodge a bucketful in and get floating away with a float.

your choice. Id personally put in a pipe and drawstring.

hire a concrete saw to cut deep and then chip out the whole floor depth and lay the pipe deep with same mix over.

Reply to
The Natural Philosopher

In message , Dave Baker writes

Quite!

Also, you may need extract ducting for dust and chips. Route the cable the same way. Benches, morticer, pull over saw, drill press can all stand near the walls anyway.

How are you going to keep the chill off?

regards

Reply to
Tim Lamb

I also need to trench something in to provide power feeds for a couple

Can you drop a supply from the ceiling/roof?

Don

Reply to
Donwill

Not for woodworking though, You need clear access.

Reply to
Andy Dingley

Too right.

Reply to
The Natural Philosopher

8' x 4' stuff on a table saw, maybe. Planer thicknesser needs a mile at either end and space to carry the work back to the front. Don't have a spindle but guess that is ends and front.

regards

Reply to
Tim Lamb

Well yes, NORMALLY.

But jig routing on a table with a moulder underneath will always end up with you needing to get to THAT side for a large piece.

If the machine does NOT have a piece of itself above to restrict where the work goes, its a damned sight better to not restrict it with cable from on high, and ,of course, cable under the floor is protected. From idiots manhandlng 8ft lumps of timber., Or letting pieces fly out of the spindle moulder, or from using chainsaws to rough out some bigger chunks.

Theres anther issue. Restriction of visibility. One office we had had pillars coming down, so naturally we used them for cables, but being in a large space with pillars always resulted in people leaning and stretching to talk to someone the other side..

I say anything you do to keep the eye level space clear is Good News. The only time services high up proved successful, was hand pneumatic tools in spring loaded pull ups, so the airlines were never on the floor or bench where they got damaged.

If a machine is free standing and not against the wall, under the floor is the only way.

Reply to
The Natural Philosopher

In message , The Natural Philosopher writes

OK but...

Let us hope Andy gets his machinery layout right first time, there are never any additions and that dust extract is by some form of magic:-)

regards

Reply to
Tim Lamb

That's why I've got the whole place CADed up. Then printed it out, stuck it to a steel whiteboard / magnetic cardstock for the machines, and played with it as a scale model.

OTOH, I don't even have a couple of the machines yet. One advantage of the new place is that I'm now in the market for 3-phase kit, which will likely be an 18" planer-thicknesser and a spindle moulder. I've left gaps for them, but can't do much more detail as yet.

I don't need much dust extraction on the big iron, as it tends to be slower and throws bigger chips. Most of this is collectable by gravity alone, as it's big and heavy enough to fall out of suspension. I'm only working at a volume where hand-dumping the chip bucket twice a day isn't a problem. The thicknesser needs chip extraction on a 4" hose and the fast stuff like routers and sanders needs high-velocity dust extraction (2" hose into per-machine cyclones) to keep it under control. The bandsaw is somewhere inbetween, but they're easy as they naturally have to have a "blind" side.

The main "island" tool is the cabinet saw. I'm contemplating overhead access for guarding and dust extraction (there's a convenient roof truss) but not for electrics.

If I go crazy with dust extraction I've got an isolated 6' square shedlet alongside which is likely to get sound insulated and used to house compressor, any multi-hp extraction kit and maybe even a hydraulic power supply for a Moog. Running 20-30' dust collection runs is no fun though: you're having to look at 6' metal pipes and that needs an awful lot of power behind the fan. Seems simpler IMHO to stick with a separate cyclone / fan on each machine.

Reply to
Andy Dingley

Pity Wales is so far away. I could dump my big bandsaw on you:-)

I take it that was 6"? Mine runs OK with 2hp. The downside of remote extraction is that you forget to empty the bags and destroy the fan motor.

regards

Reply to
Tim Lamb

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