We carried on with the preparation task of getting things tidied up and getting things ready for doing the Skylight. We put up the remaining foot-rails on the roof around the Skylight.
We then started measuring the “hole” to see what reality is, compared with our drawings. There were variations in the width along the rectangular hole, measuring 2.5 metres in some spots but also 2.495 metres and 2.520 metres in other spots. We decided that we had better pull a string from corner to corner and see whether the sides of the Skylight’s kerb is straight or not. Alas, we discovered that we have a kink in the middle. The string shows that we have about a 45 mm offset on both sides, both leaning towards the swimming lane. Oh No! We will have to take everything apart and straighten out the steel I-Beams and the two middle steel legs!! Only Kidding! It seems that the transition from the heavier wider steel I-Beam to the lighter narrower I-Beam is where the kink is and of course, we hadn’t realised that we had this little kink when we originally mounted and positioned the steel legs in the first place. We calculated that this offset is equivalent to a 0.3° angle, calculating from the length of 7.49 metres against the 0.045 metres kink or about 1 in 200 ratio. We went back to our drawing to put in this kink and it doesn’t really make any different to the shape of the skylight and its glazing panes. We will just build the Skylight with the kink in it and everything should still fit quite comfortably.
Tomorrow, we will start building the “work-table” down on the ground level inside the house so we can assemble the whole skylight module, test it and confirm our thinking about this kink.