Beam and block DPC positions

[ruggers]

I'm due to install my beam and block floor and my plans are generic rubbish, I'd like to know where the dpc should be placed. Ive attached a sketch of my build up.(insulation not added to sketch).

 

A: this Will require dpc under the beam ends. Some builders place a wider dpc under the beams, like a 400mm wide and wrap the end of the beams exposed to the cavity, then bringing it back over the top of the infill blocks at B.

 

Is this ok, or does it cause a slip plane since A & C are required.

 

😄 this will be the dpc skirt 300mm?

[Canski]

usually A & C.
C will be lapped to your DPM which goes on top of your B&B also another membrane on top of your PIR. 

[ruggers]

Thanks, it was to check how the beam ends are protected from moisture ingress from the cavity.

 

Some add plastic caps, or bitumen paint the ends, or dpc wrap as described, others just leave them exposed. The bottom of my insulation starts level with the top of the beams and a thermal block will be used for the first inner course to minimise thermal bridging.

 

The original builder wanted to have a dpc wrap from A to B, said they always do it that way.

 

I'm aware of the make up layers for the dpm and ufh, but not which way they under or or over lap the dpc skirt. The newspaper  builder will know this, but for my understanding, I'd assume the dpc hangs vertically down the wall into the room, and the dpm comes across the floor then laps up the wall, over lapping the dpc and tape sealed between the two?

 

 

[nod]

Ylift the dpc up to lay your first course of internal block Or soleplate TF

[ruggers]

29 minutes ago, nod said:

lift the dpc up to lay your first course of internal block

Masonry build here.

So to be clear, you're going from under the beams, then turn up vertically to protect the ends of the beams, then coming back in over the top of the first block thats laid onto the beam and block floor? Which on my sketch would be from A to C? 100 under the beam, 150 beam, 225 block, 100 back into the coursing, Total, 600 minimum.

 

Where as I was wanting to wrap from A to B because my wall ties and insulation will start At B, so 400 wide roll.

[nod]

5 hours ago, ruggers said:

Masonry build here.

So to be clear, you're going from under the beams, then turn up vertically to protect the ends of the beams, then coming back in over the top of the first block thats laid onto the beam and block floor? Which on my sketch would be from A to C? 100 under the beam, 150 beam, 225 block, 100 back into the coursing, Total, 600 minimum.

 

Where as I was wanting to wrap from A to B because my wall ties and insulation will start At B, so 400 wide roll.

Exactly 600 dpc I did the same on our previous build Belt and braces 

[ruggers]

Are you running the 600 dpc the full perimeter, including where beams run parallel with the wall and the cut block end beds on to the slips?
The photo looks like you do. I just can't see any overlap at the corners, it looks like one sheet which it can't be.

 

I'm doing a similar detail to this and bringing the cavity insulation down to the top of the B&B where my ties will start so I wont be able to use the 600 dpc wrap.

 

Does the lean infill need angled to the outside or optional?

 

Edited October 25 by ruggers