Posted By: crosbieYou may also find you need an interim photovoltaic supply at latter stages of construction (prior to installing the main system). And at the end of it, the interim system becomes a back-up, in case the main system goes offline.

Exactly. What I hope to do is get a watertight and moderately secure structure up then get one string of batteries and a few panels on a temporary mount for when I'm doing the more detailed stuff.

Like your barn. It's indeed a similar structure - just more cladding round the side and underneath on mine!

I suspect that DandJ may be labouring under the assumption that the visible face of the concrete pad is all that exists. From a comment on your page about one plate sitting in concrete but having mud around it, I suspect those visible pads are the tip of the iceberg..

If you're bothered about galvanising etc, just use a quality rust eating paint like hammerite, possibly overlaid with waxoyl, a rust eating car body sealant.. I've just pulled some 60 year old brackets out of a wall - a thick enamel-like paint and encased entirely in concrete and the steel they're made from is shiny as a new button..

You're stressing about corrosion of the steel, but don't forget that steel nuts in contact with zinc plate, surrounded by a liquid will set up a galvanic corrosion cell anyway.. You might end up hammeriting every nut a few times if your night worries get the better of you :)

DomJ may be referring to the fact that it looks like there has been no compaction on the concrete and it looks crumbly quite close to the edge of the brackets in some pics - it looks like the concrete was just dropped in the hole rather than formwork being built at exact spacings, tops levelled and pads pokered as one might expect when pouring that many pads. It is quicker and cheaper just pouring into the ground I know. Common when building bigger steel portal buildings, but the pads are a lot larger as well and fewer of them. It would also be less common for them to be above ground level so much in the way Eds are.

Everyone has different ideas about how to do things and what's appropriate, I think getting your BCO out to check things would be a good idea because if he's happy then it is reassurance you won't be asked to remedy it later on when it could be a real hassle. It won't cost anything for him to come out and confirm if he is happy that all is structurally sound, he won't be concerned with the aesthetics. With that many pads I don't think it is in danger of blowing over in a gale. All I can say however is that any discrepancies at foundation levels will cause problems all the way up if they aren't ironed out.

SDS battery drill a good idea, shame in a way as its the only concrete in the project. They are MUCH faster at getting through concrete. I know you are a Makita man, but I know Lidl have a £50 SDS battery drill this week, for only a few holes I would be very tempted.

Posted By: cjardPS; you drive home to charge batteries rathe than running a tiny petrol engine for a few minutes to drill a hole?

And I thought this site was about saving the earth.. ;) ;)

Yeah, terrible, I know. It wasn't plan A but there would be the embodied energy in the tiny petrol engine… ;-)

£300 gets you a £50 Titan TTB278 SDS (I have one), a £90 deep cycle 12V battery, and a £160 5kW inverter. For a bit more, with a 2nd battery, and some cheap chinese panels, you can get a SinusPro 2000S 2kW solar inverter/charger (their 5kW needs 48V).

The Titan may be heavy at 5Kg, however it's not only good for concrete, but excellent at drilling bolt holes through umpteen inches of wood with SDS auger bits. Normal (single speed) drills tend to get jammed and you have to unscrew the bit from the wood with a wrench. But maybe your design needs no holes in the wood?

A rechargeable/cordless SDS drill will do a tenth the work of a 110Ah Leisure battery. It may be convenient for the odd job, but will not be up to a day's regular use.

Are you going to buy umpteen 18V 3Ah Li-Ion batteries at 50 quid, or one or two 110Ah Lead Acid batteries at 90 quid?

Are you putting shelves up, or building a house?

And bear in mind, there's a lot more things you can power with 12V batteries and inverter than some Makita Li-Ion battery packs.

However, if you're cycling to your building site, then, ok, the Makita might have the edge.

Thanks for the clarification DandJ - you're not seeing something I don't see which is a relief as I thought you might have some specific concerns with the concrete.

Yes, pouring the concrete without shuttering is a bit of a short-cut but it was basically one lorry load of concrete whatever so it made sense.

Yes, it's not pretty with the brackets off centre on the pads and I can't say I'm entirely pleased. The engineer's spec says the 300x300 brackets need to be on 500x500 pads so in effect he's saying at least 100 mm of concrete all round. Apart from these end ones, which I'm sorting, the others meet this requirement, pretty much.

I expect the issue is that the batteries start of run out a lot quicker once they have been charged too many times. If Makita allows this, people will keep using the batteries, and come to believe that Makita tools are not good.

That may have been the intention, but it's not the effect. My 'won't charge anymore on stock charger' pack has _more_ capacity (~3.0Ah) than the others that still will (~2.8AH) (no doubt because it gets less use in practice).

Just wondering why you want to try to use only battery tools for the build?

Perhaps Ive missed something but I couldn't imagine doing a house build with out mains powered tools, it seems impossible. But then Ive often been proved wrong on building sites so always willing to learn something new.

Wish you all the best with the build, I'm going to be following with great interest, its a unique design!