epsilonGreedy Posted June 12, 2019 Share Posted June 12, 2019 I need to buy some tools for my first diy concrete slab pour, it is a ground bearing slab of just 25 m2 and 150mm deep. Following advice received previously on this forum I will be pouring the slab into a concrete block walled pool where the top of the blocks will be just 30mm higher than FFL. Access around the perimeter wall is unrestricted. I would like a finish something better than a basic garage floor should I return to doing basic car servicing in future years. I thought a long handle float about a meter wide was essential for this job but having seen the price? £300 to £400 for a metal floor mop, they must be joking. https://www.screwfix.com/c/building-doors/concrete-floats/cat8730003 Link to comment Share on other sites More sharing options...
joe90 Posted June 12, 2019 Share Posted June 12, 2019 Jeez, that’s expensive, surely not that difficult to knock one up. I would be tempted to make up a long straight edge with 30mm recesses on the ends so it can sit on the wall and tamp the concrete flat, then hire a power float to give a good finish , unfortunately I left my garage floor too long before power floating so I did not get the surface I wanted but my previous garage had a lovely “polished” finish by using a power float. 1 Link to comment Share on other sites More sharing options...
PeterW Posted June 12, 2019 Share Posted June 12, 2019 Nice tilt head bull float is only about £20-30 to hire. Wouldn’t buy one. @epsilonGreedy that is a Belle float with a very nice tilt mechanism built into the head - you twist the pole to make it go either way, depending on push or pull stroke. 1 Link to comment Share on other sites More sharing options...
ProDave Posted June 12, 2019 Share Posted June 12, 2019 Can you hire one? I used one for my concrete. Be prepared to spend an hour or more working it to get a decent finish. Link to comment Share on other sites More sharing options...
Oz07 Posted June 13, 2019 Share Posted June 13, 2019 Got great finish on 20m2 garage slab with planks and hand float. Poured 9am finished 8am next day got lucky really Link to comment Share on other sites More sharing options...
Russell griffiths Posted June 13, 2019 Share Posted June 13, 2019 It depends what you actually need the tool for in your link there are two trowels the top one is called a bull float the bottom one is a stick trowel both do very different jobs the bull float is used after tamping or screeding of the concrete, you use it in a very smooth motion in straight lines going across the slab to remove the marks left by the screed. After the concrete has has started to cure you then hit it with a stick trowel to remove the marks left by the bull float. For you size slab you will will want to hire a bull float, and by a hand held concrete finishing trowel, buy a small one as you will find a big one hard work on your wrist. You will need a plank that will span from side to side. 1 Link to comment Share on other sites More sharing options...
ToughButterCup Posted June 13, 2019 Share Posted June 13, 2019 9 hours ago, epsilonGreedy said: [...] having seen the price? £300 to £400 for a metal floor mop, they must be joking. [...] Try using one. I was 'given' a second hand one - now I know why they are expensive . The mechanism at the end (that alternates and lifts the leading edge a bit) is critical - as is the total wight. I am not the roughy-toughy I once was, and Lordy was that float heavy and the mechanism sloppy. 30 minutes was all I could manage without a rub down with the Sports News and a Woodbine. The results ? They would shame even Boris. Link to comment Share on other sites More sharing options...
ProDave Posted June 13, 2019 Share Posted June 13, 2019 I did mine all with a bull float and got a pretty good finish. the key is to keep working it as it goes off. A replacement swivel mechanism is £150 so half the cost is just that bit. Link to comment Share on other sites More sharing options...
Tin Soldier Posted June 13, 2019 Share Posted June 13, 2019 I hired one from local timber yard - £14 for the weekend big belle float. Link to comment Share on other sites More sharing options...
epsilonGreedy Posted June 13, 2019 Author Share Posted June 13, 2019 (edited) 13 hours ago, Russell griffiths said: It depends what you actually need the tool for My guide is this YouTube video https://www.youtube.com/watch?v=e6fiqAoLSRQ At time 3:05 he is using a bull float with a long handle. At 3:30 eighty minutes after the concrete delivery he begins hand troweling the semi set concrete to get a more consistent level with a square edged trowel. At 4:00 he does something unusual and moves over the setting surface using a pair of thick Styrofoam tiles to continue the first stage leveling. At 4:30 a second similar size hand trowel with rounded corners is used. At 5:20 a larger long (700mm?) narrow hand trowel with an off centre handle is used for large radius smoothing sweeps. Finally 1 hour 40 after the pour at 6:11 he returns to using the rounded edge trowel, the sound track indicates the concrete is getting dry at this stage. I cannot afford all that so taking the advice here I will hire a posh bull float with the remote head pivot feature and buy two hand trowels, one square for the firmer leveling stage and a round edge version for the final dressing/smoothing. Edited June 13, 2019 by epsilonGreedy 1 Link to comment Share on other sites More sharing options...
epsilonGreedy Posted June 13, 2019 Author Share Posted June 13, 2019 (edited) 11 hours ago, Oz07 said: Got great finish on 20m2 garage slab with planks and hand float. Poured 9am finished 8am next day got lucky really Intervention over 23 hours! I had assumed 2.5 hours after the pour there would be no further gains to be made from manual surface smoothing? Did you lay the planks directly on the semi cured surface during the smoothing operation as did the YouTube guy featured above with his large Styrofoam tiles? Edited June 13, 2019 by epsilonGreedy Link to comment Share on other sites More sharing options...
epsilonGreedy Posted June 13, 2019 Author Share Posted June 13, 2019 3 hours ago, ProDave said: A replacement swivel mechanism is £150 so half the cost is just that bit. I guess only well paid full time concrete pro's buy these infrequently hence the market does not question the price. I note there is zero customer review feedback on the Screwfix site. Link to comment Share on other sites More sharing options...
Temp Posted June 13, 2019 Share Posted June 13, 2019 Amazon have one without handle for £71.. https://www.amazon.co.uk/OX-OX-P016612-Aluminium-Float-Multi-Colour/dp/B01M17S3SF/ref=sr_1_2?keywords=OX+Aluminium+Bull+Float&qid=1560425379&s=diy&sr=1-2 Link to comment Share on other sites More sharing options...
Oz07 Posted June 13, 2019 Share Posted June 13, 2019 No in bearers screwed into the walls looked like something out of india Link to comment Share on other sites More sharing options...
Russell griffiths Posted June 13, 2019 Share Posted June 13, 2019 6 hours ago, epsilonGreedy said: My guide is this YouTube video https://www.youtube.com/watch?v=e6fiqAoLSRQ At time 3:05 he is using a bull float with a long handle. At 3:30 eighty minutes after the concrete delivery he begins hand troweling the semi set concrete to get a more consistent level with a square edged trowel. At 4:00 he does something unusual and moves over the setting surface using a pair of thick Styrofoam tiles to continue the first stage leveling. At 4:30 a second similar size hand trowel with rounded corners is used. At 5:20 a larger long (700mm?) narrow hand trowel with an off centre handle is used for large radius smoothing sweeps. Finally 1 hour 40 after the pour at 6:11 he returns to using the rounded edge trowel, the sound track indicates the concrete is getting dry at this stage. I cannot afford all that so taking the advice here I will hire a posh bull float with the remote head pivot feature and buy two hand trowels, one square for the firmer leveling stage and a round edge version for the finally dressing/smoothing. Ok you have one major problem looking at that video, and that is the concrete specification, you will need to be very specific with your order, that mix is very creamy and has a good cement content to obtain the nice paste topping, you will also notice how dry it is. Your traditional English mix is like some watery slop with some stones, very few English contractors screed like he did, they mainly tamp it with a piece of wood, that’s why they like it wet, and that’s why you read so many topics on people unhappy with their concrete finish. We really are very poor at this over here. That is why @Oz07 said they troweled it up the next day, I bet it went in like soup. Looking at the vid is a good example of how many lads you will need to help, you will need two others to place nicely and rake out, once it starts picking up you will need to work fast, ditch the idea of the kneeling boards they make more problems than they help, by the time it is firm enough to place them on you will find you will not be quick enough to finish it, you will be waiting and waiting, and then BOOM flipping hell its gone to hard to touch it and you start flicking water on top and panicking. You need a board to stretch from one wall to another so you can bull float it and then walk across the board to trowel it up. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted June 13, 2019 Share Posted June 13, 2019 Regarding timescales, our slab (RC35 IIRC) was supposed to be poured first thing, but (as often seems to be the case) the concrete trucks arrived hours later than promised. The result was that the slab got poured late in the morning. The guys didn't stop floating it until about 10 O'clock at night, as they had to wait for it to cure enough. This was compounded by the pour being during October, so the weather was a bit cool. Link to comment Share on other sites More sharing options...
Oz07 Posted June 13, 2019 Share Posted June 13, 2019 Not so much soup but was in January and just over freezing. Even had extra cement in but no joy. Link to comment Share on other sites More sharing options...
epsilonGreedy Posted June 13, 2019 Author Share Posted June 13, 2019 1 hour ago, Russell griffiths said: Ok you have one major problem looking at that video, and that is the concrete specification, you will need to be very specific with your order, that mix is very creamy and has a good cement content to obtain the nice paste topping, you will also notice how dry it is. Your traditional English mix is like some watery slop with some stones My pro self build neighbour said "just phone Henry and tell him you want a garage floor mix". I need to enquire further about what national standard Henry's local Lincolnshire garage floor mix equates to. Anyhow it is good to have some realistic expectations set as to what I can hope to achieve with sloopy English concrete. Link to comment Share on other sites More sharing options...
Declan52 Posted June 13, 2019 Share Posted June 13, 2019 The guy on the video is using a float to rub it up. His looks a bit funny because he has been using it for about 30 years so it's well worn in. The other is just a large finishing trowel. Again it's got a great finish on it as it's been polishing floors for a long time. Your brand new trowel won't get it like that. If you have never worked with concrete liked this before your setting yourself up for a major fall. With wet concrete the time you have to work with it is tiny. One minute it's too wet the next it's too dry. Or its been sent out too wet and your there till 3am before you can touch it. I would price up using a dry screed mix. Much easier to work with than a wet mix. And don't underestimate how much work physically it is. You will need some guys just bringing the concrete in and raking it out while the main guy gets it level. If you think you can rake it out and then level it out you will be clean busted before you start the trowel bit. Most of the guys I know who do screeding have shoulders like Olympic weightlifters. 1 Link to comment Share on other sites More sharing options...
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