Insulated concrete floor or suspended timber...

[Carrerahill]

The insulation is nearly done on the extension so the next stage will be to run in services and the floor make up impacts how I do this.

 

The plan was suspended timber frame, I even have C24 joists sitting temporarily on treated plates on top of block dwarf walls, all I really need to do is clean out the solumn, lay in any services that will go under the floor then fix the joists, fit PIR and away we go. However I am thinking that to be honest I could probably get it filled up fairly easily, 150mmPIR then 100mm concrete slab and it's got me thinking. 

 

Option would be to get some more hardcore down there, run waste pipes in with appropriate clean-outs etc. and then do a 75mm channel in the concrete across kitchen floor with a lip so I can have a 18mm panel sit back in - other option would be just to chuck in some 75mm corrugated duct that I can push 15mm pipes through. 

 

I could probably have the solemn filled by the weekend and order concrete next week. I am installing UFH so this sort of goes hand in hand.

 

I think I would need to duct 3-4 vents to the original house but I have plenty 4 inch soil pipe and will buy the vent adaptors. 

 

I also have a lot of old concrete block, I could "lay" these like mono-block as infill, and then grout around them with a sharp sand/cement slurry, then 100mm of hard core, sand, DPC, PIR, conc... It lets me get rid of some used but clean and otherwise OK concrete blocks - it would just take too long to remove all the mortar to make them viable for anything else - I feel like this is an environmentally good option too.

 

The rafters I have will not be wasted, mezz floor in garage? use them for building bulkheads in the kitchen etc.