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External Corner with 228 Uncured Flashing Tape

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Right. So, external corner. So, this is one of the details that we form out of our 228 uncured flashing tape. This is detail tape. It's an uncured tape, which means it stretches and once it's stretched, it stays there. It's not reverting back to its natural state. It is a tape we use for all our detail work. Sold by JJs at the linear metre, so you don't have to buy lots and lots of it, you don't have to buy 30 metres on a full roll. If you just need a piece, then you can come here and you can buy it. It's just for the detail side of it.

So, I've got an external corner here which I need to detail. This is where we need to have as much coverage as possible. We've got that 75 ml away from the weak point. So, I've precut my tape. Now, the measurement we've got here is 50 millimetres. So, I'm 50 millimetres beyond this 45 degree cut and I'm around the corner and I'm 50 millimetres beyond this cut.
So, the first thing I need to do is to remove the protective cellophane. Now, I've pre-primed this area. This primer here, this one, it needs to go touch dry. If we don't let this primer go touch dry, the gases will breathe through and we'll end up with blisters and bubbles and that within the tape. The tape is vapour permeable, so the really bad bubbles will drop out of this tape. But what we do, the way we put this down, we try not to let the air get caught underneath it.

So, for my external corner I've just removed the cellophane off the back here and I always, always drop that cellophane down. Now, that's now my safety net. As soon as that butyl adhesive touches that primer, the bond strengths are phenomenal. You will not get it off again. So, to have that safety net in place can actually help.
So, all I need to do is find my mark and I'm gonna drop my tape onto that mark. Nice and straight along the wall there and lock into place as I go. Work my way down the wall with my flat hand, stopping any air from trapping in there at any point. Once I get towards that level, I return around the corner here and I repeat that process. So, I can seal this down the wall nice and tidy here, not allowing any air to get caught at any point and then I'm down. So, I'm down onto the flat. A little roll down, dress the tape into the angle change. We don't use tilt fillets, we don't use harris rail, we're into that 45 and we're straight up. Cellophane away and repeat the process around this side here. There.

Now, this is where we start the stretch. Now, there aren't many systems out there where that will come to there without cutting. You would have to normally cut it. But with this tape being the sort of tape it is, we can stretch it and it will stay there. The reason we use this tape in particular. It's uncured, so it will cope with a stretch. So, this is the tape we use for our detail work and it's an uncured flashing tape, so it's actually capable of a large amount of stretch and it doesn't revert back to its natural state. So, once stretched, especially on these details, once you've done that stretch, it stays there. You know, there's no returning back to its natural state. Once it's stretched, it stays exactly where you've put it.
So, I'm gonna start my stretch here. I've got a bit of slack here, so I'll sit that down as soon as I get it. I'm pulling away from my corner there and I'm going round and I'm repeating the process here and as soon as I get a bit of slack available, I need to sit it in to primer very, very quickly. So, stretch away and I'm manipulating that tape. I'm forming that stretch. So, I'm trying to stop any air getting in at any point and I'm pulling it away and I'm stretching it down.

That is our external down. That's our... It's down. The tapes are down. It does require a bit of extra work. The whole thing needs a really, really good roll with a pressure-sensitive roller all over and any areas where we've got a change of angle we must, must lock into place. So, from that point out we lock off. From this point we lock off. We're stopping the air getting in at any point there. And that there is the external corner complete.
Minimum tools - a roller, a brush and some HP250. That's our external corner complete.

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