MortarThePoint

Thank you for all the suggestions. Hopefully it is a bridge we won't have to cross. We have already been through all the site investigation phases and there is some old road planings that need to be dug out anyway, other than that all good so far.

Thanks guys. We will use professionals for all of this, but I wanted to work out if there was a way of reducing the amount that went to waste if the issue were to arise. Fingers crossed!

I'll crush and reuse all the concrete I can, but if any is contaminated with asbestos it would need to go.

Thanks Russell, but I'd be keen to get it off site. As I understand it, the 'rules' do allow you to use such material on site if your landscaping plan requires raising levels and it is then suitably covered by clean soil.

Hope everyone is having a nice break over Christmas / New Year. Thank you to those who might be working. We are clearing our site ready to get started in the new year. Part of this involves demolishing some ex commercial buildings that are in the way. The largest (300m2) was built in 2010. As there were previously old sheds on the site (seen in some aerial pictures) I am nervous that there could be fragments of asbestos roof sheeting underneath the concrete floor, and worse could be stuck to the concrete. Sending asbestos contaminated concrete to landfill is eye wateringly expensive. If the concrete is 150mm thick and all had to go it would be 45m3 and cost about £13k, of which about £10k is landfill tax. Businesses would be able to reclaim that tax, but not us selfbuilders as far as I can work out. I don't know if the problem exists, but the risk is pretty stressful and I need to be prepared if it does occur and we end up under pressure to make decisions (plant on site etc). Any thoughts as to how to reduce the quantity of concrete would be greatly appreciated. There are some companies that undertake the treatment of soil contaminated with asbestos fragments (Provectus and Biogenie) and I think that involves hand picking at their facility. Bonded onto concrete is a different matter though. I have thought about 'planing' ~120mm off the concrete to thin it before lifting and therefore reducing the quantity to ~9m3 (£3k). I had a quote for water cutting and it was 10s of thousands so not viable. Any thoughts would be gratefully received and hopefully provide some sleep filled nights. Hopefully won't be needed but pays to be prepared.

The total area is 300m2 (~100 panels) so it would take about 5 days (~40 hours) to liberate the lot. As new it would be worth a pretty penny, but in this sort of condition there are occasional listings on eBay at around £10 a panel. I wouldn't need that much and I've already learnt that I can't chase every opportunity even when it's tempting to do so. I hate to have it go to waste, so I will talk to the demo guys about whether they can get it out faster with a 20 ton digger.

Thank you for all the suggestions. I gave it a try using a mini digger and after about 2.5 hours I had freed up 5 whole panels and 2 half panels so I'd say it's it's not worth the effort. The panels are not it great condition either, but will hopefully be useful for something. It was interesting to see that the interface between the panels and the underlying concrete was completely wet. Some pictures of how I got on:

Nice idea, I've got lots of 18mm ply as well.

Speedy look to do one for about £110 a week, but I don't know about the blade. I think it would take an age to lift all the rectangles though. If they were 1m2 they would weigh about 100kg each and there would be 300 of them. That's 5 hours if it took only a minute to shift each one and I think it would be more 5 five minutes each though.

I'd thought of that and think that would be the end of the road as it would then takes ages

I like your thinking Mr Punter, can screed become MOT Type 1 as I need plenty of that? The photo is probably a bit confusing. I think you're referring to a thin draft strip in a metal channel that the perspective makes look thick.

Russel griffiths, you must be pretty nifty with it as it would scare me trying to get the right height without gouging the insulation.?

It wouldn't be rewarding if it was easy, that's what I have to keep telling myself when it get's hard. It's also important to appreciate my limitations though so I will be getting the ground works contractor to do the major demo work that is beyond unbolting.

Nice idea Ed Davies, but the foundations etc will be very different.

Thanks Onoff, I have a fork lift paying me a visit soon so I can ask them to try that. I fear the sledge hammer will do too much damage to the insulation. The 300m2 would also be pretty daunting by hand. I had wondered about using a walk behind saw to cut rectangles and lift using concrete anchor eyes. Even that would take a long time.

I've been dismantling a cold store type barn ~300m2 in footprint. I have exposed the makeup of the floor and it looks like there is a screed ~50mm thick below the floor tiles, a DPM/VCL and then 100mm of Celotex insulation. It would be great to reclaim this insulation as it is expensive and would save on waste. Does anyone know how I can go about extracting the insulation intact without it taking forever? I have attached a photo, this is the worst bit as it was below an exterior door. The rest looks like it was built yesterday.

You are right AnonymousBosch, it's a hard balance but hopefully I'll get it somewhere near right

Thanks joe90 it's difficult to know where to turn sometimes and so I am please to hear that ?

Hello everyone. I can't believe I have only just discovered this forum, I've clearly been looking in the wrong places. We have permission to take down some ex-commercial buildings and replace with a house which is very exciting, if it took a while to get. It's been a long road already (looking for ~4 years, then permissions etc) but we are now starting the exciting bits. I fill my weekends with dismantling the largest of the buildings which is a well insulated kit type barn. That's been going well and hopefully next year things will be going up rather than down. I want to be as hands on a possible including laying the bricks/blocks etc. I'm not in the building trade, but am practical and (hopefully) good at taking advice. As always, the challenge is to know what things you don't know that you should (the unknown unknowns).