Bricks or Blocks below DPC

1 Dec 2019
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United Kingdom
My architect has specified the below.


The walls will be rendered so blockwork to both skins above DPC. Is there any benefit to either brick or block below DPC? Blocks are cheaper to purchase and i guess quicker to lay so why do people use bricks - What am i missing?

Also there is no mention of insulation below DPC. Should a celotex type insulation be used to fill the cavity between the lean mix and rockwool above DPC.
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You wouldn’t render all the way to the ground, you’d stop the render at DPC and have bricks below it
So bricks unless you want visible blocks.
Can the bricks/blocks below DPC be rendered as long as there is a gap so as not to bridge the DPC? Bead below it and drip bead above it?
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Render shouldn’t be in contact with the ground.
Blue bricks with dark mortar is normally a smart looking option. Or whatever other frost rated bricks you might like
If you want to render above and below, use a wider roll of dpc so it extends through the render.
I filled my "water trough" with Dritherm.
They look different
Ok so no structural difference then purely the look if exposed.

The spec calls for turbo blocks above DPC but i have heard these can cause issues when rendering. Does using dense 7N concrete blocks give a better build (slower on the laying)?
If you’re rendering, then yes a dense block rather than an aerated block is more sensible for the outer skin.
Thanks 23vc. If plastering internally and for ease i assume that there is no issue using dense blocks on both skins (its a very small area).
It’s more to do with u values and there are lots of different types of block available. So generally you’d have a more dense block where it’s rendered, and either aerated or other lightweight type for inner skin
Is that much of a concern if using full fill 100mm cavity insulation? In the new area of blockwork i have to fix a lot of timber to the inner skin and thought that dense blocks would give a better fixing.
You’ll need to achieve a certain u value for the wall as a whole, so you need to work out your options with type of insulation, type of block etc.
Inner skin of non-aerated block is very common so unlikely to be an issue
Render shouldn’t be in contact with the ground.
Blue bricks with dark mortar is normally a smart looking option. Or whatever other frost rated bricks you might like

This is what I went with, blue engineering bricks and black mortar (tone).

I also went for 7nm blocks above DPC on the outer skin as they apparently better for rendering. I went for fibolite blocks as these are 'lighter' than normal dense concrete blocks...but I have found that although I can lift them one handed, I am not strong enough to lay them single-handed without making a mess of the placement.
Do the 7nm dense blocks add to the structural stability of teh external walls or is it purely to better accommodate for render/fixings. As said i have a very small area at the front so i cant see the brickie being to upset about it. The rear may be more of an issue due to the amount of blocks involved.

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