Casting Padstones with building sand

[unspecified]

Background: Currently extending out the back of the house, opening up the kitchen and dining room into the new extension. SE specified three padstones in total, 2 of 300 x 300 x 150 and the centre one as 450 x 300 x 150.

It was quite difficult to find padstones of this size, as they span both inner and outer skins of the wall. Contacted SE and he said it's fine to cast my own, should be done using 1:2:4 cement/sand/gravel.

When making concrete before I've just ordered ballast and just mixed the two, however on this occasion I did buy the individual elements to make the padstones but picked up building sand rather than sharp sand

Fast forward a few weeks and the beams are in, padstones were put in first then beams on top, relaying all bricks on top of steels since most were fairly easy to remove, rather than dry packing.

I've only just thought about it whilst reading another thread, now I'm slightly concerned that they won't be up to the job so after some advice!

I have no problem with doing any job properly, so I'm happy to prop the steels back up and cast in situ another padstone mix and try again. Thoughts?

 

[tony1851]

Manufactured padstones have a much higher crushing strength than 'home-made' ones are likely to achieve, but with the sizes you have there, and the relatively low loads (assuming the spans are 3-4m-ish?) you shouldn't have any problems.

 

[^woody^]

It depends on how the padstones were made.

If you just made a box and poured the concrete in, then it would not matter if building or concrete sand was used, they are likely to perform equally crap.

 

[unspecified]

Yep, spans are almost 3m for the one opening and then 4.5m for the second opening.

Concrete was mixed, poured into moulds and tamped with timber, with the sides being knocked to try and force any air out. Then levelled and left to set.

Ideally I would have just bought them, but unless anyone can suggest where to get them from this was my only option. My account with Jewson only had concrete block sized ones or smaller for bearing on single skins. SE wasn't happy for two padstones on each skin.

Wickes sell a Blue Circle 40N ready to mix in the bag concrete, that was my only other option but it would still have to be cast in the same way.

 

[tony1851]

If it ain't broke, don't fix it.

 

[unspecified]

If it ain't broke, don't fix it.

That's certainly a good way at looking at it! There's no obvious signs of any issues currently, and like Woody said, there's no way I'm going to be able to create a certified padstone to 50N or so at home easily.

Probably over thinking it tbf.