Block choices for foundations above ring beam

[dnb]

I have just got all my piles installed - blog photos will be up soon - and am preparing for the ring beam to be completed. I have a plan, section drawing and buildup scheme worked out with my architect that makes sense and meets my requirements. I now come to find the parts and I have a few choices to make so am looking for a few words of wisdom.

 

The inner leaf is specified as 215mm 7.3N block work, a 60mm cavity and an outer leaf of 100mm blockwork. The beam and blocks sit on the inner, followed by another course of 215mm wide blocks. The sole plate of the SIPS panels sits on these blocks. (Note I have neglected DPM, telesope vents etc for simplicity in this description.)

 

I have found 215mm dense concrete blocks locally, but they are hollow. I don't much like this for either the sole plate attachement or supporting the beam and block.

The next option in dense concrete is a 140mm block and a 100mm block together. With mortar, it's more like 225, but there is space on the beam to accomodate this.

The third option is a thermalite hi strength (or the Celcon equivilent) 215mm block. It looks like the easiest option but various people have warned me off these (reasons seem vague)

I can't find any 215mm solid concrete blocks locally. And I probably wouldn't be able to lift them even if I could!

 

I am leaning towards the light weight blocks at the moment because they have the right material specification, are a little better at insulation and will be easier to ship and handle. (The shipping is always a concern when you live on a small island serviced only by ferry.)

[Russell griffiths]

You won’t find a 215 solid, they are too heavy and I don’t think they even make them any more. 

You normally use a 100mm block laid on its side, two courses brings you back up to height. 

 

If you get the right blocks you can you can probably save a chunk of cash by having a full load, as you can use them in the block floor as well. 

Edited February 3, 2020 by Russell griffiths

[dnb]

6 hours ago, Russell griffiths said:

 

If you get the right blocks you can you can probably save a chunk of cash by having a full load

Good call. The floor needs approx 1000 blocks. The wall build up is small in comparison.