markc

Welcome, High ceilings are good, old buildings with thick old stone walls (no cavity), uneven floors, no DPC under concrete floors etc etc etc. can be cold and hard work! ... but everything is do-able and someone on here will have seen it before.

4:1 will be fine, i would fill to almost level in one go, leave to go off and then finish to level. this will prevent sagging while wet

What is the building construction? or at least the balcony floor? this will affect the choice of waterproofing

If you are dead against any form of skirting and finish is not important I would go for a sand/cement render mix and a a hard corner (piece of concrete lintel or steel) to prevent the exposed corner chipping off. Plaster wont stand up to the knocks from vacuums and sweeping etc.

Got to agree with @BMcN

Welcome and sounds like an interesting project.

No idea what the blocks are, but i am curious why there is what looks like skirting on the ceiling

waste disposal

M12 through 3x2`s is massive overkill, plus 1200mm centers is too far to be of any real benefit. Clamp the timbers together and then screw or Annular ring nails in a zig-zag pattern at around 150-200mm spacing. (this is how trusses and joists are doubled or trebled)

where is the small area that squeaks? mid span? near a wall? service void? etc. i reckon it could well be a joist hanger/connection noise depending on location

some of the pans do slope towards the front, i always assumed it was to ensure any splashes disnt rest in the joint line. i wouldn't bung the hole up as it could cause the whole pan to fill with water and stay there ... although it would be clean water so no real detriment.

fresh air .... and the condensation disappeared

Nope, if you can score 3 sides, sharp bolster hits (not hard enough to break it) to the 3 sides and then crack it and it will break pretty cleanly

thats how i would do it

Generally speaking, single thread for softwoods, end grain and polyethylene (soft plastics). twin thread for hard woods and chip/OSB etc.

If you are going straight through, then the length of cable covered by the insulation is short and will not cause overheating, so yes its ok to seal around the hole.

Good idea, technically the joists could just sit on the shelf, no fixings and be stabilised with noggins both ends.

How are you looking at fixing them? Really should have vertical plates welded to the box sections to fix to

Thats a pretty good description

It will, but unless the lamp fittings are really tall no one will ever notice the small tapering gap, i thought some i did would annoy the hell out of me but ive never notioced them.

Yes, 6mm studding into 8mm hole is about as small as you can go or the resin nozzle wont go into the hole far enough to pump it in and let the air out

Just put a packer under the top edge, dont `seal` the back as water will get in but then cant get out

As big Jimbo said, clean dust free hole is the secret, also (If possible) use a drill in reverse to push the fixings in - the thread then tries to force the resin back into the hole and ensures it is forced into the masonry or concrete pores/cavities and fixing threads, something we learned while installing thousands of them on big construction projects.

16mm SWA is more than sufficient for this purpose. Close the duct off with some insulation or squirty foam. Also drill your hole though the wall slightly downhill towards the outside to prevent water creeping along the cable and into the house.

@MortarThePoint, Again, most floor stiffeners/noggins are there to prevent the joists/beams from rolling over when loaded. If you look at a pozi type joist (its easier to explain than a solid member) then floor bounce occurs when the top cord compresses and/or the bottom cord stretches allowing the joist to deflect downwards. Solid noggins or Diagonal (top/bottom/top/bottom etc) mid or part span braces have very little effect on deflection. If you want to reduce floor bounce you have to increase beam depth or increase section on the top and bottom cords