Ho hum - time to remedy.

[Onoff]

I wonder if you could fill the cracks with say molten solder then seal over the top...

[Hecateh]

My sparky today was talking about a job he had recently done where the owners had diy'd a resin floor with marbled dyes.  They said it looked good - if you liked a pink, blue and purple marbled effect.  

the surface is was good though

[MikeSharp01]

Ok so I am getting there with potential solutions but I want to press on so I thought I would move ahead allowing for all permutations when fitting the sole plate. The cost of the finish won't change much once the sole plate is down as long as I leave the internal walls out for now. SO I need to get a sole plate detail that ensures we can either go down (easy) or up with a screed.

 

Its all about making sure the DPC comes out above the screed - so here is my thinking which would allow up to 60mm of screed assuming the mortar bed, which sits on the DPC, is about 10mm:

 

Is this a runner, any thoughts?

[mvincentd]

On 06/08/2018 at 13:03, jack said:

Can you experiment with gently grinding/polishing a bit of the slab that'll be out of sight and see what you come up with? It may be that you can get away with some sections (maybe per room?) with a bit of aggregate on display and other rooms with no aggregate showing.

My powerfloat had some 'failed' areas and I experimented with grinding those smooth.....however the moment a diamond grinder goes on the surface it creates a distinct edge....which i've yet to succeed in feathering off to the powerfloat.  I also hired a slow spinning machine with 5 carborundum blocks on it...this was quite gentle so minimally affected the powerfloat while doing fairly well at smoothing the 'failed' areas.  However theres typically unevenness at the transition area and it struggles with this, ultimately failing to feather.  I'm still experimenting.

@jack I love your result...fairly seamless transitions in and out of exposed aggregate....I just cant find the machine with the right balance of oomph/finesse.

On 05/08/2018 at 21:36, MikeSharp01 said:

The polish we achieved was not good enough across the whole house

Assuming by 'polish' you mean powerfloat,....what are the bad bits like?  I found the rough areas that didn't float well to be much softer and so responsive even to a p40 grade sanding disk on a 4" random orbital sander...it's just the bloody transition that I cant feather.

 

On 06/08/2018 at 11:37, MikeSharp01 said:

Jackie is not keen on the terrazzo look and I think that is where we would need to go with it. 

Agreed, i've not been able to find examples of a grind feathering back into a powerfloat.

 

Also wherever i've tried hiring concrete grinders its as if they know nothing of the theory of working through the grit grades....machines come with whatever disk is on it.

[jack]

7 hours ago, mvincentd said:

 

@jack I love your result...fairly seamless transitions in and out of exposed aggregate....I just cant find the machine with the right balance of oomph/finesse.

 

It may be more than just the grinder choice.

 

The surface was power-floated to within an inch of its life before a grinder touched it. It was actually pretty shiny even at this point!

 

They then came back with the grinders a few days later, before full hardening.

 

I vaguely recall them saying they used a very specific mix to make sure it polished well.

 

Overall, I suspect a good result involves a lot of parameters.

 

Perhaps the key is to learn to love the transitions and find a way of living with them. We have three or four spots where it's clear the power float was stopped, leaving four dark lines. There are also some very ropey areas along some edges and corners where the hand polishing with a small grinder really didn't work. We've just accepted that concrete is a variable product and learned to love the rough bits.

[Ferdinand]

1 hour ago, jack said:

Perhaps the key is to learn to love the transitions and find a way of living with them. We have three or four spots where it's clear the power float was stopped, leaving four dark lines. There are also some very ropey areas along some edges and corners where the hand polishing with a small grinder really didn't work. We've just accepted that concrete is a variable product and learned to love the rough bits.

 

Do polished concrete floors get sealed? What with?

 

There should be nothing to stop you imposing a pattern on top if you find the right material, before sealing. A long time ago my father stenciled a border onto a (I think) chipboard floor with an appropriate type of paint., as opposed to trying to hide that it was a cheap and cheerful material. The effect was to turn the chipboard tinted by the sealant into a background texture.

 

I think it was resealed once or twice in a couple of decades.

 

But he had the same sort of resin / fibreglass experience as @SteamyTea, and was an architect to boot. There may have been a tinted sealant under the stencil, and a more transparent one on top.

 

I would not have expected it to work, but it did. I would probably not be that bold without a lot of homework first.

 

There is probably a type of paint that would do it over concrete then be sealed. Just one way to alter the impression.

 

Best of luck.

 

F 

 

Edited August 10, 2018 by Ferdinand

[Ferdinand]

8 hours ago, mvincentd said:

i've not been able to find examples of a grind feathering back into a powerfloat.

 

That sounds like the same texture quality issue as trying to touch up over a spray painted surface. It may be necessary to rough up an entire section / room, or create a feature (eg area for a sitting area or a dining table).

 

Or I suppose one could rough it up in patches across a region so that the larger texture becomes the feature.

 

F

Edited August 10, 2018 by Ferdinand

[mvincentd]

4 hours ago, Ferdinand said:

Do polished concrete floors get sealed? What with?

If gone through the full grind process to fully polished I don't believe they need any sealer.  Powerfloats are hard to use a sealer on without defeating the object of the powerfloat and roughing the surface.  Mine is also waterproof concrete so I have to use a topical (not penetrating) sealer.  Watco do a powerfloat sealer that doesn't require any surface roughening.

5 hours ago, jack said:

Perhaps the key is to learn to love the transitions and find a way of living with them.

Absolutely......i'm experimenting for the hell of it but am actually happy already with the house showing the scars of its difficult birth....thats a personal aesthetic though and @MikeSharp01 might not have it in his minds eye, hence I was detailing my experiments more in the hope they might help him....i'm speculating his powerfloat has 'suffered' some of the same characteristics.  Yes, probably a lot of parameters to add up to a great result..and a spot of luck also in the mix! 

[MikeSharp01]

On 10/08/2018 at 13:39, mvincentd said:

i'm speculating his powerfloat has 'suffered' some of the same characteristics.

Yes I think so, we are still working out our next step and all the above experiments might form part of it. I am meeting a concrete grinder on site Monday so I hope to have a full prognosis and all the options thought through quickly after that.