Leaderboard

The spray is a cleaner and a finisher. You can't lick your finger and wipe CT1 like you can with silicone, as this stuff works underwater too the multisolve is used AFTER preparatory cleaning of the surfaces has been done, and is basically there to remove contaminants that could stop the CT1 adhering properly ( and thus making the process a waste of time and money ). You'll also need the MS to clean up afterwards. It's a bloody handy spray which also removes cured silicone from tiles etc, and general cleaning where conventional cleaners won't shift it. DONT leave it on any surfaces as it soaks into silicone, for one, and dissolves it nicely. NOTE : The white CT1 goes custard yellow and looks terrible. Don't use it as a finish anywhere where it will be seen ! Use clear, wipe it all but completely off, as a sealant, and then go over the top with white silicone as a finisher The other colours are fine, grey, beige, black silver etc, as is the clear. The white sucks, but is still good for purpose.

Do you still have their number?

Use a listening rod. It's a rod around 4ft long with a cup on the end that you stick over your ear. Poke it on the ground along the run of the pipe and you'll be able to pinpoint where the leak is. It's what the water company use, believe it or not. It works a bit like a stethoscope. You can probably make one. The ones I've seen have been something like a fibreglass tent pole, with a hard rubber disc on the end you hold hard against your ear.

This needs to be a really good sealant to make that joint 100% air tight - frankly I don't like the idea of there needing to be packing under there anyway, as it's asking for poor airtightness and indicative of a foundation that wasn't properly laid. It also means that the frame is putting point loads into the foundation, rather than having the load evenly distributed. You need to seal this gap up to absolutely, 100% stop cold air getting in under the sole plate from outside, anywhere, as that risks cooling it and causing interstitial condensation from vapour movement that could, in time, cause the untreated timber to rot. Can you get at both faces of the sole plate? If so, then injecting low expansion foam as deeply as you can get it, from both sides, may be an option. It's going to be fiddly to do, but you are where you are so have to deal with this somehow. After injecting low expansion foam and after it's cured, then sealing the remaining edges with a decent quality PU or MSP sealant will stop moisture penetrating the foam (the foam is fairly air tight, but will most probably be vapour permeable).

Bear in mind that, with no air anywhere, there may well be a marked variation in pressure with temperature. Water volume increases with increasing temperature above 4 deg C. Because of this the pressure will vary, as it's a closed system with nowhere for the additional volume to go (except the air bubbles that will inevitably be in there somewhere at this stage). Odd things happen when you dissolve gasses into water as well (which is what will happen with an initial fill like this). Ideally any pressure test like this needs a near-constant temperature. There is another effect too, caused by the way concrete contracts slightly as it cures. This is useful, as it causes it to grip reinforcement very tightly, but a nuisance when you have pipes running through it and are trying to measure pressure, as the pipes will be squeezed as well. This means you can see a slight pressure rise as the concrete cures and very slightly compresses the pipes. I'd not take too much heed of any variation in pressure measured between pre-pour and post-pour. It's likely that there were temperature variations, and the effect of the concrete initial cure, that have messed up the readings. Best to do the test when conditions are stable. FWIW I didn't bother with any pressure testing at all. I took the view that the pipe was pretty tough, there were no joints anywhere and a visual inspection would be fine. I used the same philosophy as when laying MDPE water pipe, where the chances of the pipe itself developing a leak are so close to zero that it's commonplace to not bother pressure testing it before backfilling trenches.

It could well be due to the heat of the concrete curing has increased the pressure and it has now settled down keep an eye on it over the next 24 hours as it should have stabilised.

Repressurise and give it another 24hrs. There's a lot of pipes coming out of the slab, what's the method for pressure testing all those, and what are they all ?

Then I think I can give my 'seal' of approval Bonding the timber down with CT1 or sikaflex will pay dividends IMO, in addition to a couple of mechanical fixings.

What sort of temperatures can you expect the genny cooling system water to produce? Eg I'd have firstly thought about heating a very big primary TS ( adjacent to the genny ) as an additional heat battery, say 1500-2000 litres, then, when the TS is fully charged, would it be better to glean the heat from the TS and export it to the cylinder in the house or would it be better to use a diverter valve to send the heat directly to a secondary TS or UVC ( via a dedicated coil )? They'd have to be hydraulically separated I assume as the external arrangement would need antifreeze / inhibitor etc.