Can I build my threshold like this?

[VDubDan]

So as alluded to in my other thread, I basically didn't do anything regarding door thresholds when I built up to DPC - so below DPC is just one continuous cavity wall all the way round.

I've got my oversite concrete in, and walls/roof build up and that's it for now. Obviously there is a doorway built in above DPC

Just wondering if there was any problem with the following approach to the threshold:

• Knock out inner leaf bricks down to the level of oversite concrete
• Use half bricks to "return" the internal leaf to the exterior leaf up to below DPC height
• Lap the DPM so that the DPM goes up the outer leaf
• Pour new concrete in the cavity up to oversite level
• Insulate above as normal, 25mm upstands all round
• Screed as normal

I figure this is a solid, long term solution and pouring that much concrete won't take me many minutes (I have cement and ballast left over). I shouldn't ever see any movement near the threshold that might risk cracking screed

 

[noseall]

• Knock out inner leaf bricks down to the level of oversite concrete

This bit's ok.

• Use half bricks to "return" the internal leaf to the exterior leaf up to below DPC height
• Lap the DPM so that the DPM goes up the outer leaf
• Pour new concrete in the cavity up to oversite level
• Insulate above as normal, 25mm upstands all round
• Screed as normal

​

Don't return the bricks. Use cavity closers to shutter off the cavity and then line the trough with polythene and screed up to the slither of perimeter insulation against the door. We tend to ask the customers what floor covering they intend using before fitting any insulation against the door - gripper rod fixing and all that.

 

[VDubDan]

This bit's ok.

​

Don't return the bricks. Use cavity closers to shutter off the cavity and then line the trough with polythene and screed up to the slither of perimeter insulation against the door. We tend to ask the customers what floor covering they intend using before fitting any insulation against the door - gripper rod fixing and all that.

Cheers! We're going tiles so no drama there.

I'm just a smidge confused - would you literally just put a normal cavity closet at the bottom and insulate/screed over that?

Nothing underneath?

 

[noseall]

Nothing underneath?

Sorry I was on about the wall cavity. Yes, you can continue the floor insulation into the door threshold.

 

[VDubDan]

Sorry I was on about the wall cavity. Yes, you can continue the floor insulation into the door threshold.

Sorry if I'm being properly dense mate, I just can't wrap my head around the detail! What do you have under the insulation? Or do you mean the insulation just goes above the cavity closer?