UKH

Pic attached 

An old concrete fireplace base in our bedroom. Ideally should be levelled down to be flush with the floor.

Any ideas on how to do this would be welcome.

Can't see from pic how much higher the fireplace is than the boards, but depending on what floor you plan (carpet, laminate?) you might consider laminate floor underlay fibre board beneath the carpet underlay or laminate. Commonly available in 5mm but other thicknesses exist. 

https://www.screwfix.com/p/wood-fibre-underlay-boards-7m-15-pack/7824R

About £2 per square metre

Hack it all out and re-lay it.

Be easier to break out and lay some chip board flooring. May have to remove the boards on either side or fit a timber frame before flooring. Break down and use a self leveler is another option.

Hilton TE80 with a transformer. SPEEDY hire.

Hilti TE80. Don't think the Hilton does beakers m 

That small an area is possible to grind away fairly easily but it's quite dusty work.

Thanks.What tool would you use?

Thanks. We're a second floor flat. Any idea if the use of that would effect the ceiling of the flat below? Cracks...

Ta

you could grind it, it you've got an angle grinder: https://www.toolstation.com/diamond-concrete-grinding-disc-100-x-22mm/p6251...

but that could be time consuming and a bit of a pita.

if you're going to break it out, I'd cut slots in it first (angle grinder with diamond disk) - this makes it easier to chisel out bigger chunks - any sds drill on hammer mode will do it.

depends a wee bit on what the plan it to finish it (I tiled the concrete ex-hearth in my bedroom, left it as a feature for standing pot-plants on)

seriously, if you're going at it with a grinder or cutting disk - get a quality mask, the rubbery type with replaceable filters, and consider setting up a extractor / blower to get the dust outside....

What DaWalt said. In fact I think he's covered it all!

Hire or borrow a small belt sander with 40 grit diamond belts. I've used this Bosch one for sanding floorboards, and it should also be good for levelling a small patch of concrete: 

https://www.tooled-up.com/bosch-pbs-75-a-belt-sander/prod/198529/

Slow going and very dusty, but you can reduce this by attaching a vacuum cleaner hose to the dust outlet. 40 grit will destroy the floorboard edges so try and keep the sander away from them.

I assume you're laying carpet/underlay on top? In that case the finish won't matter. 

Bear in mind building regs probably stipulate some sort of fireproof hearth in front of a fireplace, so if it's got any chance of being used in the future I wouldn't remove it completely.

Cutting slots with an angle grinder and chiselling between them will work well if you want to go down a centimetre or more, this is my standard procedure for chasing in granite or concrete block walls. It makes industrial volumes of dust though, and the risk of silicosis is quite real so a proper mask is essential.

It's a small patch, a cheap 4" angle grinder will make light work of lowering that. Either grinding disks or 40grit flap wheels. Flap wheels are more controllable but will probably work out pricier. It's dirty work: mask, goggles (it'll get round glasses), stick a towel under the door to save the rest of the house and run the hoover in the room with you to filter the air (not very kind to the hoover if you have a fancy one or that might get you in trouble but the dust will end up in there one way or another).

jk

I wouldn't do this unless you plan to re plaster the ceiling in the room below.

These hearths are usually just poured into the lath of the ceiling roughly supported by the structural timber around it. If you try to break it up it will destroy the ceiling. 

Personally I would go with the slit and chisel method that Dewalt mentioned.

It will be dusty but nothing like as dusty or time consuming as trying to grind it down.

As a few others have said, invest in a decent mask, we used to use Sundstrom SR 100 masks at work. Forget the disposable ones, some are very good but without a face fit test you won't know until its too late but with something like the Sundstrom the seal is that big and squashy it fits most people. 

I have ground concrete with one those. Slow it won't be. Dusty - - - really good extraction required.

I would try a scutch chisel.

https://www.toolstation.com/footprint-scutch-chisel/p51712?utm_source=googl...

Will probably do it unless concrete mix is superstrong. 

Less dust, steady away. Cheap. And you will be able to see what you are doing which is tricky when there is a lot of dust coming off it. 

Have a like for supplying advice dependant on the actual construction in the bedroom  and flat below.

Might be a lot safer to put a wardrobe or set of drawers over the old hearth

I have recently done this in a first floor bedroom. I was lucky that it was only about an inch thick with rubble underneath. First try drilling in to it to get an idea of how thick it is. If it's not very thick you can probably lift it out if you can get under it, this is what I did.

Drilling will make less mess than an angle grinder and will help break it up. If it's really thick then grinding and chiselling is probably your best option. 

Once you have removed enough of it you can either use self levelling compound or board it over to get it level

now that's using your loaf - rather than just setting about it with with brute force and ignorance

Thanks,

I only know this because I own a house that seems to be of a very similar construction and considered doing the same myself until I lifted a few floorboards to inspect some wiring ans saw what was really there. In the end I used a fibre-reinforced resin to smooth out the transition to the rest of the floor and bought a slightly better underlay for the carpet that went on to of it. You could still feel it to some degree but for the majority of the time I was living there there was a king size bed covering the spot so no worries.

You could hire a pneumatic scabbler. Job done in five minutes - disputes with neighbours forever after

It's only the width of one board and looks like it was for a gas fire. The picture's not clear but it doesn't look like there's a traditional fireplace. 
It already looks cracked. Probably quite thin. I think you'll be lucky and find you can chisel/lever it out. Let us know what happened!

Reminds of this Swiss Tony sketch:

”You know, smoothing down concrete is very much like making love to a beautiful woman. First of all you need put on your goggles and dust mask. It might be worth letting the neighbours know that there’s going to be lots of noise and banging. And finally, turn on the extractor fan, turn up the radio and smooth away. “

Grind?? Have you used a grinder indoors or seen the mess made when someone thinks it's a good way to chase a slot in a wall to trunk some cable or something.

The words dust and mess don't even begin to describe the problem I agre it's an option, but surely this is last resort.

If it's a second floor flat, it might be nothing much worse than a fancy paving slab type thing. You might be able to just rip it out, but do it carefully

'Take your tool in hand and get ready to drill or hammer away as the job demand'

Its been done now. Heavy duty power drill and chisel bit plus pry bar. Removed the concrete from one end exposing the layer on which it sat then pryed that away with help from the drill.

Well done. On a totally unrelated note, watched a group of young jays a few days ago. 

Nice!

Been feeding two adult jays at the park. They're getting more comfortable with me.

However most of my bluetit and great tit horde have disperswd for the summer