Structural walls in the middle of my B&B floor

[Tony L]

@Mike  Thanks very much for taking the trouble to post these two images.  Yes, you’re right: what I have, according to the builder, is what’s on the left, & your drawing shows the beam placement accurately – ie it’s on the edge of the blocks that come up off the poured concrete. I’d have rather had what’s on the right, but with the addition of a DPC between two blocks below the bottoms of the beams, & an aerated block penetrating my insulated floor, to prevent a cold bridge.  As I’ve said, there was no detail to show either the left or right solution on the builder’s drawings, so I’m going to have to be happy with what I’ve got, & I am reassured by roughly half the BH community saying this is the way to do it.  Also, my SE is happy with this, as are the LA BCO & the warranty inspector.

 

I was talking about starting at an edge to remove blocks all the way to the middle so I could have a look at what’s been done, but according to the warranty inspector, I can just smash the blocks either side of the supported block, & look in from the sides then replace the blocks.  That sounds easy enough, so I’ll probably do that before we start building up off this part of the floor.

 

@Canski There’s DPC under the ends of the beams where they sit on the two long sleeper walls that divide the ground floor into thirds (see image at top of thread).  For my two piers (which are the subject of this thread), there’s DPC, as shown in my update of Mike’s diagram, below, but there isn’t DPC directly under the sections of beam over the piers.  I know this, because the beams were put down & blocks were being placed into the beams, further along, before the builder built up the support under the beams & block that are over the foundation piers.  So blocks will have been laid onto slips & mortar, but if there’s any mortar under the beam, it will have just been pushed in from the side – not ideal, to my mind.

 

The B&B is finished now, apart from a few loose blocks around the perimeter that are waiting for the ends of the periscope air bricks to go in.

 

Thanks again for your input on this.  I’m surprised to learn that these two solutions don’t have any part that mitigates the cold bridge – so my internal structural walls will be sucking heat out of the house & transmitting it straight through nothing but concrete, into the ground & the cold air beneath the B&B.

[Mike]

21 minutes ago, Tony L said:

Also, my SE is happy with this, as are the LA BCO & the warranty inspector

If your they're all happy, problem solved! Just make sure that it's done properly, so that the block is actually supported beneath.