Onoff

Nice and cheap and has a phone app: I just found this on AliExpress: ￡24.98 | Tuya WiFi 15 in 1 Air Quality Detector CO/CO2/HCHO/TVOC/AQI/PM0.3/PM1.0/PM2.5/PM10/Temperature/Humidity/AQI Air Quality Monitor https://a.aliexpress.com/_EHYJGnQ

Random site but another option. Solvent weld one of these on the stub pipe:

To me the photos look like you already have a "double female" connector in place on each soil stub coming up. You can see there's a little internal stop that the pipe inserts as far as. In your case, more importantly it stops the connector slipping down. Each appears to then be capped with one of these. These can be simple removed by getting a flat blade screwdriver under the lip and levering up. As an aside I always use a silicone spray or smear of silicone/plumbers grease when assembling this stuff:

Mine in the picture above is old colours, red, yellow,blue,black 10mm². Red sleeved with brown, blue as is, yellow sleeved with green/yellow and black left spare. I'm coming in through the back of the EV charger as coming up into the bottom is just plain fugly imho.

I mulled something like this:

Just run separate SWA and Cat-6e to your EV charger like I am:

Well worth a a watch:

You might also consider running your SWA in oversize ducting. You can then run Cat-5/6 cables etc in smaller ducting within.

Moisture resistant plasterboard is GREEN!

Tanker.

No he didn't say that at all. No offence but you come to this with seemingly zero concept of what is to most a basic understanding of how you mix concrete and the ratios. You're being given good advice. I'd suggest you listen / take it. You risk people ignoring you. "2 x half gates will be more stable Quick sum. All approximate. 45 gallons, 200 litres. Concrete is 2200kg/m3. so 440kg. A big bag of ballast is 800kg. So with cement and water one bag will do 2 barrels, approx. If not quite, then chuck in some rubble. Presumably you will cut the tops off the drums".

I'd think about insulation under the floor, like 150mm min. If you're laying a concrete slab then why not incorporate UFH pipes now even if you never use them? You'll want the walls insulated too. Pointless not too. At that size I'd have put a trench in with soil & water pipes coming up through the slab as future proofing. Decide on your plan where you might later on want a WC / shower room.

I had a Vaillant boiler in a rental with BG's top cover package for years. It was annually serviced by them along with multiple call outs and failures along the way. Not once did any of the engineers mention there was no mag filter fitted or recommend doing so. It got to the point different BG engineers were saying different things. One would order parts then another turn up to fit them saying they were the wrong ones. Another did suggest a power flush might work. I got so fed up I outed BG and employed a family friend to fit a new boiler a lot cheaper than BG. He did attempt to power flush the old system first to cure the old boiler but to no avail. At the outset he said he'd attempt it but it was unlikely to do much. Think he charged around £300 for the flush. He did add cleaner & leave the apprentice there all day with the flush rig running saying he wanted to see "clear water" running out of it before he called yay or nay on the boiler. Sure he said modern boilers have quite a small heat exchanger that's prone to blocking which is why the system must be kept clean and have inhibitors in it. Something too about, again modern,heat exchanger materials being prone to corroding / blocking.

The small 20mm ducts are for Cat-6e cables for the EV charger, PV, gate intercom, CCTV etc. I'll use a shop vac to suck/blow draw strings through them.

I just PUSHED a 16mm² SWA and two 20mm conduits through a 21m 63/50 corrugated duct. No draw wire and 4 bends on the run. Thanks to mine and my lad's patented, 3D printed bell end esque pushy thing and a good dose of lube!

You should really have had a power flush at the time of the new boiler maybe? A cruddy old system can as I understand it block even a newish boiler. Old man had BG install a new boiler and they didn't flush the old system first. Had repeated issues thereafter. Changed multiple parts and at one point even removed the mag filter they had previously fitted. Utter farce tbh.

Power flushing won't necessarily work if your boiler is goosed.

It won't set particularly well and be a very weak mix if you're talking about a standard bag of concrete. For an 800kg bag of ballast you'd need x5 20kg bags for an 8:1 concrete mix or x10 20 20kg bags for a 4:1 mix. You might achieve a circa 500kg barrel weight with a well vibrated mix, probably a bit under.

ChatGPT says:

I would clean that up with a bleach solution and scrubbing brush then apply shower tanking paint and see what happens.

@zoothorn put one in his riverside shed / cabin as well:

Neatly cut and stick some insulated pb around the faces? You'd have to mitre the corners to ensure the insulation layer is continuous.

Some cold bridging maybe? Make airtight & insulate?

Our first Starlink, bought from Costco in the UK was faulty out of the box. Called the US helpline. New one was delivered the next day if I recall. Customer service is brilliant.