Roundtuit

May I suggest Mumsnet. I'm sure someone will have an answer that aligns with your requirements.

OK, it's only an AI summary based on limited information, but it passes the laugh test. Did you read it? If you have, and assessed the risk as acceptable, crack on 👍

I think you're getting confused between one bag of cement and one bag of ballast. Have a re-read and come back if it's still not clear, but fundamentally, I think the consensus is that using barrels full of concrete as free-standing gateposts isn't a great idea.

Is the 3 inches the full depth of the rafter? If so, I'd be cautious of hanging any additional weight off 75mm rafters, and be looking for a solution that added strength not just extra load I think.

The ratio is the same no matter how much you mix. The tabulated quantities are approx what you need to mix .204 m3 (which is 204 litres or roughly 45 gallons). As above, more details required. I'm struggling to see where 45 gallon drums fit into this.

Google suggests:

Surely. Unless you're building it big enough for the sheep as well.

Hire a couple of hand pallet trucks and use one each end maybe? Just remember to build it on blocks so you can get the trucks under easily.

I have a separate thermostat for upstairs. What have you got upstairs that should be 'calling for heat'? TRVs?

Probably just tape the small bits. For anything bigger, I believe the recommended fix is to slit the membrane horizontally above the damage, slide a patch up and in so that the top of the patch is on the inside of the membrane and the bottom of the patch is on the outside to shed moisture, and then tape in place.

Once it starts, its like an expensive roller coaster ride that you can't get off until it's liveable. Pace yourself, improvise, adapt and overcome, and remember it will be worth it in the end!

Wheelbarrow and shovel for me, or bucket and trowel for really small mixes, but that amount doesn't go very far.

I've got a 10ft container to pretty-up at some point. I think I'd drill the holes first and screw from the inside into the timber, or weld a few angle brackets on to avoid holes in the skin.

Probably not a massive oversight then; more a difference of requirements. Night latches usually require additional locks on the door for security so are superfluous with multi-point locking systems. I can't really see an overwhelming argument for having one tbh, but if you can, probably best to replace the door with another timber one and fit one.

I'm guessing you're used to a nightlatch type lock?