Onoff

Was it maybe covering the soil pipe at one time and slipped when backfilling?

Put a few extra rivnuts in and you've easy access for a periodic squirts.

Spray inside the box sections with ACF-50 when it's all done.

A raindrop bounces up a nominal 6" when it hits the ground. It's why house DPC is traditionally at 6" off the deck. Maybe clean the area and run overlapping, horizontal, beads of clear CT1, starting at the bottom.

I just put your picture in ChatGPT along with your question: https://chatgpt.com/share/680d3594-29ac-8006-9ae4-c42b6e6afa1f

Sadly he died the other year 😢

Me and my then neighbour:

I did my own imprinted concrete in 1991. A strong concrete mix with lashings of waterproof PVA at 5:1 and red dye. I imprinted it with a pattern made from an old wardrobe that had some tacked on batten for pseudo mortar joints. Once imprinted a dipped a 1/2" brush in black dye and went along the joints. I then dipped a broom head in the black dye and spattered it over the lot. I never sealed it. It still looks like new now:

😉

The Lidl one is a wet spray so graphite in a carrier. It's good. I usually hold a rag behind if spraying on window hinges. If doing a door, open it ajar and place some rag or something absorbent on the floor. The powder one is this sort of thing that you "puff" in: https://www.ebay.co.uk/itm/376002352482?

Lidl do a good graphite spray.

Get some graphite oil spray in there or graphite powder in a puffer.

Pah! Last "big" unit I was involved with replacing was 540 kg, 150' up.

Got adders in my compost pile.

I reckon get two blue MDPE barrels with lids, one smaller than the other. Lay a slab of PIR in the bottom. Place the smaller blue barrel in the bigger one with decent gap around the edges - ideally the gap the same as the insulation slab at the bottom. Fill the small barrel with water. Drill some holes in the outer barrel and fill the gap with expanding foam. Then an axle...a support frame...a hinged hatch... Or something like that.

You can use grey foam pipe insulation slit lengthways if you don't have any foam backer rod. No Nonsense silicone remover works well if you do get any on the bricks. You could...underfill the gap with Illbrück FM330 then silicone over.

Time for the old gloved finger check?

Seriously, you might want to invest in some leak detection dye.

🤭

Every hole's a goal 😉

"foams" is an anagram of sofa...sort of... 😉

Would you screw on a joint like that? (I wouldn't).

I'm thinking a few more plasterboard nails wouldn't go amiss...

This will likely remove the silicone from the bricks. Worked for me when I made a mess:

Sorry but that looks like a quick bodge. Just had my roof done on an 1863 cottage. I'll let picture show the difference. Re-mortared (though probably not lime based as original): I have used buff coloured silicone mind, where my sliding gate posts project from the brick pillars. (This so the gate moving etc doesn't impact the pillar as much as if it were solid mortared). That would have been better than the white your lot used but still not right. This is what I used: https://www.toolstation.com/silicone-825/p93228