Dunc

thanks for the reassurance! Yep, generally very happy with my groundworks team. Quick, efficient, adaptable and communicate well, and to the untrained eye seems good quality work. If anyone reading in future wants a recommendation for a groundworks team in the Highlands drop me a line!

I noticed that my groundworker has provided the soil pipe penetrations of the slab with a male end up-over (currently covered with a female blank). I had expected to have female ends up as I presume it's usual to have flow from a male end to a female to reduce risk of leakage...is what he's done normal? (am I worrying about nothing prior to setting all this "in stone" 😉)

Any tips on fixings/glue for installing compacfoam at door/window thresholds? The foam blocks are 100x150mm section and will sit directly ontop of concrete block work. They are 970mm long so I need to install several end-to-end to make up the 3m openings under some large windows.

Anything up-stream of your meter will belong to SSE, as far as I know, so they should specify. Others here may have better advice.

Just lay some duct with draw rope in it if you need to go ahead before you have the specifiications for the pipes/cables. Water will have to be BLUE duct 110 external/90internal, minimum 750mm under ground. Marker tape in the trench ~200mm above this. Make sure you take lots of photos with tape measure to show depth as in my experience SW were fairly stringent in their track inspeciton. Electricity will need to be black duct. Make sure that there is appropriate separation between the ducts vertically and horizontally if they are in the same trench.

Great to see! Must feel like a big milestone achieved? Hoping for our MBC frame up early May. I see they've moved away from the green-faced OSB internal airtightness finish.

Just to feed back on this in case someone else has this question: Marmox tech support (yes, I should have phoned them first!) confirmed that the sealant is only recommended where airtighess or DPM function is needed; there is no problem using the blocks without the sealant.

I don't see why not. Maybe need a bit of plastic down first to stop the screed running through any gaps? Are your joists engineered to take this load? Another alternative is laying the pipes between 25mm battens and surrounding with a dry mix.

Specifying a course of marmox thermoblock to break a thermal bridge in my foundation blockwork. Is there any value in using the sealant? Tech data from Marmox says "Marmox sealant should be used to seal the ends of the Thermoblocks together to prevent moisture creeping up between blocks and to ensure air tightness of the building." I don't need the air tighntess as that's dealt with at the timber frame/slab junction and the blocks are below this. It's outside the DPM so I don't need the blocks to be sealed to keep water out of the rest of the structure, just wondering if there's concern with water ending up bewen the blocks?

This is where I've got to at the moment. Suggestions welcome!

@Big Jimbo not sure I can envision this - is this a cast concrete (or similar) cill with the door sitting on top?

@Kelvin Did you solve this? I have a very similar detail to complete and no great ideas...

Marmox in 12.5mm + 4mm + skim = 19.5mm? Bit of a faff using the two board thicknesses, but gets you close to the required 15mm PIR? Our window fitter (going into a timber frame) has requested a 10mm tolerance, which I thought was rather large.

Useful feedback @Redoctober, thanks! Can I just ask do you have any creaking problems with the upstairs floor? My architect is pushing hard for the Lewis deck & screed which he says would remove such a risk. (apologies to @North Coast Self Builder for hijacking the thread!)

Won't the acoustic insulation between the joists be providing sufficient insulation to push most of the heat up in to the upstairs rooms? That's what I'm hoping will happen for me Despite the general consensus on the forum that UFH is not needed upstairs, where people have provided data, there seems to be a 2-3oC drop from downstairs. Most people reporting this seem to have near-passive type houses. Problably fine if you're sleeping, but if you use the rooms during the day (e.g. work from home in an upstairs office, kids play room) maybe not so good? Just my humble opinion. However, that 2-3oC can probably be provided in other ways like towel radiators, panel heaters and the like. I don't have the technical knowledge to do the calculations to know how much heat would be required upstairs, so I'm putting UFH in as it's relatively inexpensive in the grand scheme and not easily retrofitted. Caberdek on joists, plastic sheet (maybe not needed?), UFH pipes clipped down, dry mix sand&cemet ("Pug" mix) surrounding the UFH pipes, between 25 or 30mm battens (depending on UFH pipe diameter and clip size), caberdek on top to support final floor covering. @Redoctober has a very nice blog post on how theirs was done if you can find it. I think this will work out about £1500 cheaper than Lewis metal deck with liqid screed for me, over about 57m2 and seems very DIY-able. If paying a contractor, I'd just do the liquid screed as that will be much quicker.