[Long] Arsecarrots! Or, Asphaltic crap, floor planers and general brutality - and builder related death

[Tim S]

Jules wibbled:

Like a pingfuckit, but more circumstantial rather than event based :)

[Phil L]

Nearer to 500 methinks

£150 plus VAT here for an 8 yard, but how big is the floor? - I assume a 4 yd will easily do it

a m3 of anything, be it concrete, earth or insulation will cover a 10m2 are

100mm deep...my guestimation of that room is about 12m2?

So if you take 200mm off, this will be about 3m3, then you add 100mm of jablite polystyrene insulation, cover it with DPM, and order 1.5 cubes of concrete to give a depth of 100mm - no screed required, no paint-on chemicals and one man could easily do it in two days

Digging out concrete isn't as hard as people imagine - a 15lb sledgehammer and a good pickaxe will have it in manageable sized lumps in a few hours, plus a few more hours to barrow it to a skip, then a brisk rake over to get the extra depth, and if you want to cut a few corners, you can use 75mm insulation and 75mm of concrete, which is more than adequate, which means less digging, less skip space, less concrete to buy, but as you appear to have made your mind up, good luck, but I'll reiterate WRT the floor scrabblers - they don't work

[Tim S]

Phil L coughed up some electrons that declared:

Hi,

I have to admit, I hadn't realised that screed was optional...

Thanks for the good advice. I'm going with the plan I have because I'm comfortable with it. If I follow every opinion, I'll end up blowing around like a reed in the wind ;-> Sure you can see my position. I don't think your advice is invalid, but just that I'm not comfortable with it in this situation. Next time maybe :)

What I should have done is to research and quantify the problem 6 months ago to my own satisfaction instead of subbing the whole job to builders who where far from expert in flooring matters. Given the whole picture, I might have gone for this solution up front.

However at this stage, I'm not up to concreting (it's 21m2 BTW) such a large area and I'm not letting another builder in the house (plasterers welcome though ;-> ) - rather live or die by my own hand this time.

Thanks for the good luck - it will succeed...

But - there will be a couple of "next times". One is the shower room floor and the other is a possible future conservatory. Both do get new floor slabs.

You mention that screed is optional. But I presume, not, if one is going to stick wet underfloor heating pipes in? Or can these be buried in concrete, assuming insulation under the concrete?

Cheers

Tim

[Dave]

Big snip

Is this one of those machines much like a rotating vertical cylidrical object fitted with tungsten carbide cutters on the bottom?

If so, the builders had to use one of those when the concrete arrived for the new school classroom. They couldn't get any water into it and it was setting as they laid it. They spent the next 2 days trying to get the floor smooth and level.

Dave

[Tim S]

Tim S wibbled:

Follow up:

Hired something like one of these (in the 110V, not petrol):

(at half that price - we like our small local hire shop :)

It has a drum like this on:

's noisy, it produces more dust than even an angle grinder (though heavier so it does settle down quicker).

But it does certainly work! We took about 95% of the asphalt crap off - small trace patches left only and a strip round the edge where the machine can't go. Strip round edge dealt with with a very sharp wide SDS chisel.

Machine made light work of thin old cement levelling compound - asphalt crap took several passes but it was a pretty painless exercise and well worth the 45 quid + VAT hire.

It was powerful enough to grind down 1cm off a high area in fairly hard screed too.

The finish is generally flat with slight grooving. I don't see any problems now in getting a good key for the next layer.

I did try it on the hall to see how subtle it could be on rubbery glue residue on screed - answer - with careful control of the height knob, it is subtle enough to scratch that off without major damage to the screed.

In the end, the hire time was expiring and I decided the very thin and non asphaltic glue residue in the hall and other rooms was unlikely to be a serious problem to applying floor tiles etc, so I didn't bother doing those. If faced with that alone, something with a wire brush on would probably be better.

Re-did this too. Once the acro prop was in it took all of hand effort to remove the old blocks. The so called tying in to the old wall consisted of exactly 2 screws protruding into the new mortar courses.

Pathetic...

I cut out some of the screed down to concrete to give a good seating to the bottom brick, soaked the concrete in SBR twice to aid in water resistance and primed with cement/SBR to give a good bond.

Every 1/2 brick in the end of the old wall was previously removed with an angle grinder and SDS and the mortar cleaned off, including any exposed frogs.

Did a new column in brick and a 3:1 sand/cement mortar (normally too strong for regular brickwork but it's my standard for repair work like this). All new bricks were soaked in a bucket of water and the the old brickwork sprayed twice with a garden sprayer. I aimed for zero suckage.

Where possible new bricks were oriented so that new frog was adjacent to old frog to give an extra mechanical bond.

Mortar was packed in medium wet until every joint was solid.

Acro came out the next morning and the brickwork is most certainly not going anywhere... Very pleasing result... I will wager it will stand a club hammer if allowed to cure for a week or so...

Cheers

Tim

[Andy Burns]

In practice, even the Brandon hire shops work out at about half their catalogue prices (and it's not like I'm a regular hirer or anything).