Beam and Block floor finishing questions

[If in doubt...]

Just lining up to slurry, DPM and then insulate and finish a suspended beam and block floor (built by others).

Is it best to fill the small narrow gap running the length of the outer beams edges and the inside wall (Cavity wall thermalites) with either mortar or insulation etc. or just leave and let the floor DPM block it off? Was about to fill with mortar to tighten everything up but then wondered about bridging in some way seeing as it's below DPC.

Then where the ends of the beams meet near to the end wall in to an external doorway, the beam ends are sat over the inner leaf and builder looks to have put DPM running up the inside of the outer leaf single course block that is below the door. End of that DPM is loose and I'm assuming that can be tucked under the door, where the DPC also is and then when I run the DPM over the floor it also meets the DPM tail and also gets tucked under the door / DPC?

Elsewhere round the walls they've left DPM tails coming out the walls for the Floor DPM to tuck up under but with the doorway being different just want to make sure I get it right.

Ta

 

[Swwils]

You will want proper perimeter insulation, expansion gap foam roll is not enough.

Ensure that the perimeter insulation isolating the screed has a minimum thermal resistance of 0.8Wm2K/W and is at least 25mm thick to prevent cold bridging.

The upstand should also overlap the wall insulation, with a minimum of 150mm from the bottom of the wall insulation to top of the insulation upstand.

Consider UFH now if you haven't already.

 

[Apacheuk]

You will want proper perimeter insulation, expansion gap foam roll is not enough.

Ensure that the perimeter insulation isolating the screed has a minimum thermal resistance of 0.8Wm2K/W and is at least 25mm thick to prevent cold bridging.

The upstand should also overlap the wall insulation, with a minimum of 150mm from the bottom of the wall insulation to top of the insulation upstand.

Consider UFH now if you haven't already.

Any particular brands that you recommend for under floor heating?

 

[Swwils]

Wet system attached directly to insulation, anhydride screed on top. Yes it takes ages to dry yes it's a faff but done by right contractor and it's very good.

 

[If in doubt...]

You will want proper perimeter insulation, expansion gap foam roll is not enough.

Ensure that the perimeter insulation isolating the screed has a minimum thermal resistance of 0.8Wm2K/W and is at least 25mm thick to prevent cold bridging.

The upstand should also overlap the wall insulation, with a minimum of 150mm from the bottom of the wall insulation to top of the insulation upstand.

Consider UFH now if you haven't already.

Cheers - there's enough gap to get a decent thickness of insulation in there so I'll go with that.

Did initially consider UFH but the room is a tack on to a bungalow and represents less that 10% of the total floor area - and there is unlikely to ever be anymore work done so I felt to introduce a new element on that basis was not ideal. There was also an existing radiator where the knock through is giving me a now redundant rad feed that needs to be taken care of - so will now run in to the new room.

 

[Swwils]

Cheers - there's enough gap to get a decent thickness of insulation in there so I'll go with that.

Did initially consider UFH but the room is a tack on to a bungalow and represents less that 10% of the total floor area - and there is unlikely to ever be anymore work done so I felt to introduce a new element on that basis was not ideal. There was also an existing radiator where the knock through is giving me a now redundant rad feed that needs to be taken care of - so will now run in to the new room.

Big rad sounds ideal then, you'd be surprised how much impact perimiter insulation can have, especially if it's the "weak point" in the insulation.