Cheapest Way to Achieve Polished Concrete Floors (or Similar) in New Build

blobert

Hi There,

We're working on a large new build passive house (bungalow) at the moment. The plan would be to have wooden floors in most areas but we were keen to have polished concrete (or somthing that looked similar) in corridors, kitchen, utility room and maybe bathrooms. We're keen on a light grey very minimally exposed aggregate look like this:

As the house is already coming in way over budget I'm looking for the cheapest way possible to achieve this. The plan was to have the slab, 300mm of EPS insulation on top and then a screed layer. We've decided to skip having underfloor heating as it was hugely expensive so there won't be pipes needed for this in the floor.

My initial thought was to maybe use a screed that could be polish so we could put it everywhere and just polish the bits we want to use. But there does not seem to be many options here and the one or two I found were massively expensive.

I'd looked at other options such as tiles that look like concrete (they don't look great and are quite expensive) and maybe putting in a topper layer that can be polished, but again this was crazy money at €260 per m2.

I'm wondering if it might be possible to use a layer of concrete (maybe some easier flowing version) instead of a screed and just polish this?

As with a lot of other parts of the house we've tried to reduce costs on, I find there's often a way cheaper solution that's close enough to the really expensive option if you look hard enough but I'm struggling here!

Any suggestions would be much appreciated. I asked my architects/builder but they dont have any great solutions.

Biker1

"The plan was to have the slab, 300mm of EPS insulation on top and then a screed layer." The standard for a Passive slab is to have your structural concrete on top of the 300mm EPS and floor finishes above. No screed required.

Dudda

The look you're after isn't cheap. Personally I can't see how removing UFH and replacing it with radiators is a saving. UFH is just cheap pipe that's rolled out. It works out about the same as radiators. Anyway if you're looking for savings you'll have to do without the concrete or concrete looking alternatives. Polishing it isn't cheap. If you look hard and long enough you may find some cheap concrete looking tiles. Again getting them laid won't be free either.

sydthebeat

polishing is incredibly time consuming and thus why it is expensive.

is it something youd try to do yourself? perhaps you can hire a polisher and there are loads of youtube videos on the subject.

SodiumCooled

Personally I would be forgetting about the polished concrete long before considering removing UFH - can you still reconsider I think you will regret this for decades I would see it as in the top must haves in a modern house.

Also the cost difference should not be that big, I was being advised by "experts" I was mad to be considering UFH upstairs and that rads were fine but on chatting with my plumber (also a friend) he said the cost difference would be minimal and the system would be just much better as an all in one. Regardless of cost I dont want ugly rads upstairs either so will be putting in UFH on both floors regardless.

sydthebeat

https://www.boards.ie/discussion/comment/119178875#Comment_119178875

not if the house is certifed passive... and it doesnt look as though our climate is going to become any colder in the near future

blobert

Thanks for the replies guys.

Just on the heating front the heating/ventilation system with heat pump, underfloor etc was coming in at over 90k installed which was crazy for a house that will need incredibly little heating (whole house only has heat load of 3.5kw). So we're dropping the heat pump/underfloor and using electric heating panels in the plasterboard of the walls/ceiling. That + similar MHRV system and a sort of heat pumps system for hot water is costing <25k installed. It'll be less efficient for sure with the heating but I'll be long dead before I'd make up the near 70k in savings from the heat pump!

On the flooring I realise the concrete polishing process itself is expensive/labour intensive. But my thought is if could just put down a concrete layer instead of screed, we could kill two birds with one stone in that we could put floorboards over some areas and polish the others. In theory the layer of concrete should be a fair bit cheaper than screed so that should allow us to have concrete ready to polish for less than the cost of screed and way less than having to put screed down, then a concrete layer, then polish this.

Let me know if you think this sounds feasible?

PS I looked at tiles that look like polished concrete but they are expensive. They's probably work out as if not more expensive than the polished concrete route and look substantially worse.

sydthebeat

90 k for heating and MHRV ???

sounds like your building a huge house.

maybe cutting down the size of the house is a better way to save money?

on the polishing, teh aggregate used in a typical concrete slab / screed isnt very good for polishing. You would be much better off sourcing an aggregate that is designed to be polished ie some with shells etc in it.

some tips here

https://www.renobuild.ie/blog/expert-tips-for-laying-concrete-to-achieve-unique-polished-floors

blobert

https://www.boards.ie/discussion/comment/119180649#Comment_119180649

Thanks, yes it is a very big bungalow with a load of windows in so it was always going to be pricey. Keen not to reduce in size but there's lots of areas (like with the heating) where we can shave a decent amount off the price while not sacrificing too much.

Thanks for the link, that's a good read.

I'm finding with a lot of stuff there's a huge variety in pricing to achieve pretty much the same thing. For instance we are using porcelain tiles for the patio area, the architect was suggesting ones that cost €150 per m2. I found similar ones from Spain that look nicer, are better performing and are costing me €12 per m2!

Likewise with this, despite price rises, concrete is still a very cheap material. While I get the grinding is avery labour intensive and I'm fine with paying someone €80+ per m2 to grind it (we only want very light grinding, no exposed aggregate), where the price seems to be getting silly is when some of them want another €100 per m2 to pour it. We're talking about a 70-80mm layer, concrete is give or take €100 per m3 so in theory €100 of concrete should cover 10+ m2 at that level (ie <€10 per m2) so their pricing seems nuts.

Thus if possible I think it makes sense to get someone else (cheaper) to pour the concrete and just have it polished if this is doable. I've thought about doing it myself but it does look hard work and I'm wary of messing it up on first go. I suppose I could try it out in an area that I'm going to be covering with timber first to get the hang of it.

Thanks again for the advice!

Dudda

Have a read of this from another thread here on Boards:

https://www.boards.ie/discussion/comment/105768995#Comment_105768995

The pouring of the concrete is a skill and takes ages. They guys were powerfloating the concrete in my house (circa 100 sqm of polished concrete) until 2am the day it was poured. I've put in polished concrete floors in lots of projects from houses to universities and other public buildings all over Ireland. Very few in Ireland can do it correctly and I've seen some incredibly expensive modern houses (that have won Architecture awards and featured in magazines) that have terrible polished concrete floors because they did them themselves. I remember visiting one award winning house in the west and was shocked. Blown away shocked! It really looked terrible but you can't see it properly from the photos in magazines. They just got the builder who had no experience to pour the concrete floor. When the guy came to polish it their was nothing he could do to fix it so just grinded and polished as best he could. I also know of another project (county council offices) where the polished concrete floor has cracked all over the place because they put the concrete in wrong. I also remember watching Dermott Bannon on Room to Improve and they visited this very cool modern house in Dublin. They had a rug in the middle of the floor to hide a crack in the polished concrete floor. I took a screenshot of it at the time and it's someplace on my phone but can't find it right now. (EDIT: see below post with photos) I'm one of those guys when everyone in a new modern art gallery is looking at the art, I'm looking at the architecture and materials.

What's even stranger the less grinding and polishing you want (which you'd think is cheaper) the more perfectly smooth the concrete has to be and therefore the more the person pouring the concrete has to powerfloat and ensure it's super flat. Honestly €100 per sqm is about the going rate to pour a concrete floor correctly and a fair price in the current market. You might also need to hire a concrete pump which is another few hundred.

As I said earlier the whole process isn't cheap and if you cut corners it will turn out crap and it can't be fixed. If you're on a budget you can get some convincing vinyl floor coverings with polished concrete effects. I've a few Forbo samples currently on the desk beside me we're putting into commercial toilets that are very convincing.

Dudda

In relation to my above post I found the photos (when looking for something else) I took of the TV when Dermot Bannon brought clients to a modern house in Room to Improve. 19th September 2019 it was on. Apologies for the quality

This is a close up of I think the bright kitchen door he was proposing. You can see the crack at his feet.

You can see the length of the crack here. It gets worse as you get to the couch.