Category: Build Progress

Over the last three days, we have been measuring, calculating, sorting, adjusting, calibrating and humping all sorts of stuff that are all aimed towards the next stage of creating the Rafters that makes up the majority of the roof structure.
We started on the “A” wall and measuring the distances from the wall to the PA diagonal rafter and also up on the steel I-Beam too. It was proving difficult to get an accurate measurements. Even after we built a laser projector so that the detector would find the laser beam up on the PA rafter but even this proved a bit wild. So we waited for the darkness, in order to see the red laser beam directly shining a line right on the wood surface and drew a pen mark at those points. The following day, we then measured these marks and even this was a little wobbly too. after careful thoughts and discussions, we concluded that the only reliable measurement was the rafter that fits up onto the steel I-Beam, this one is called A6. This measured as 4815 mm. we moved along to A16 and measured that one too, which came out as 4840 mm. we know that the steel I-Beams are straight so we calculated that for each subsequent rafter, we added 2.5 mm to the length.

Then we humped into the workshop 21 lengths of the 89mm CLS timber, but we discovered that most of the timber was rather wet from rain showers we had over the last few weeks and the wind and sunshine has not been strong enough to dry it off fast enough. We will need to sort out the pile (see previous blog report). Anyway, we needed to put 17 of these CLS timbers into the Bird’s Mouth template. But we needed to adjust and recalibrate the template so that the Bird’s Mouth was coming out at the correct depth, size and angle which is 32 degrees for the “A” wall. We verified that all was correct now, and then proceeded to cut these Bird’s Mouth and Angled ends on the 17 lengths. After that, we put 12 of these into the “scarf” joint template plus 12 shorter pieces and today, we glued and screwed together this scarf joint on these 12 length (A scarf joint allow two pieces of timber to be glued on a long diagonal resulting in a longer piece of wood). They are now drying overnight.
To confirm that we were on the right track, we took outside one of these new scarf joined pieces and cut it to length then we went to place it up into the A6 position and discovered that the length was too long. We then realised where our calculations were being misapplied so we have updated our spreadsheet to take this into account.

We are learning! Phew! Tomorrow, we will go through the task of slicing up all the plywood sheets into 400mm wide strips and then put the resultant huge pile back under cover outside!

Today was the day when we grabbed the three rafters that we created yesterday and the day before, and took them outside to get them up and installed!
We only needed to do some little extra work on them in the workshop like putting the bevel slope on the longer MN rafter and round off the edges where all three fitted into the metal brackets.
But first, we went out to slice and remove the cement board and bit of wood off the top-plate for the outside corners (the NO and OP corners) where the eves are sticking out, and the inside corner (the MN corner) needed the pointy bit sliced off the top-plate too.
So after that preparation tasks were done, we got the first rafter, the OP rafter, out and it went up and slid into place more or less straight away. We then glued and screwed tight the corner post against the cement boards and then We got the rafter itself all glued and nailed just before lunch.
After lunch, the second rafter, the NO rafter, also went up and installed with little fuss too! WOW! This is good!
Then we started on the third (the very last LVL special rafter – this was the MN rafter) and lifted it into position and slid it down into the metal bracket .. and it got stuck half way in! The rafter was too long. We had already glued and screwed the corner post into place as well and aligned it all up correctly, but the rafter seems to be too long. So we brought the rafter back down to the ground level and roll out our power planer to take a thin slice off the bevelled end and tried fitting it again. it didn’t get all the way, still 50mm short! So again, rafter came down and more slicing was done. Up it went again and .. nope! It didn’t fit, gap down to 35mm now. this was repeated two more times and we got the gap down to 15mm so we filled the gap with a lump of wood and settled for that solution. All was glued and nailed into place.

That concludes all the LVL special rafters .. 12 corners (5 valley types and 7 hips) and 3 ridge rafters (1 straight and 2 bent with 45 degree elbow joint). It took a long time to do all these (2 months!), but they are a major structural element of the roof and they have to be well prepared and carefully created so we couldn’t cut corners!! The next job is to start making the regular rafters (the 400mm wide ones) and they don’t need to be so fussy about cleaning joints and don’t use special LVL timber, also they come in regular shapes and sizes so we should be able to get a mass production scheme of working and get many more created and installed quickly.

Today, following from yesterday’s job of preparing for NO and OP rafters, we sanded and vacuumed these two rafters so it all came together and got glued and nailed tight shut!
Then after lunch, we tackled the third and final LVL special rafter for corner MN. This one is 413mm wide and 5420mm long on the bottom flange. All the bits and pieces were sliced and chopped at the required angle of 26.6degrees, clearance notches and noggings etc. The webbing and LVL timber were sanded and vacuumed as usual and then glued and nailed together.

We managed to do three rafters today, they are sitting there drying and will be ready for tomorrow when we hopefully can get all three outside and installed into position. That would be nice – grin!

Today, in lovely sunshine, we started to get the final set of special LVL rafters created. We first went outside to install the three corner legs for MN, NO and OP corners. We chopped a small bit off the ends to make them fit nice and tight into their corners and then measured the distance of the bottom flange from the steel brackets to the face of the leg, down at the correct point. The numbers came out pretty close to the drawing as follows: NM was 5420 mm, NO was 4350 mm and OP was 4320 mm.
After an early lunch, with our freshly printed drawings of the NO and OP rafters, we started preparing all the material bits and pieces. The webbing plywood was sliced down to the correct width of 436mm (we had already made eight of them but at a wider size of 455mm), then sliced angled ends (32.7 degrees) on all of them in pairs. The LVL timber was next to get the treatment of being chopped with this 32.7 degree angles and then the bird’s mouth marked and cut away too. Finally, a heap of internal noggings (both straight and angled ones) were made. The final job of the day was to cut away clearance gaps within the webbing, at the wall end so when the rafters are lifted into place and slid into position, the wall’s top-plate can wiggle into the rafter and settle into the bird’s mouth properly without jamming up.

And in the afternoon, we finished off slicing all the remaining polystyrene sheets into 250mm wide by 38mm thick strips.

The 14 boards were sliced (using our hot-melt wire machine) into five chunks (four of them 250mm wide and the fifth 200mm – the left over) and then pushed all these into the machine flat with three wires to slice them into 38mm thick strips. We made a total of 210 strips. These are now ready for when we start creating all the regular rafters that builds up the main part of the roof structure.

We then moved them all outside to wait for use.

This morning, we finally managed to get out there and get the big heavy O Ridge rafter installed!! We checked to how dry the rafter was and brushed off the dirt that has splashed on from all the rain we had!!
It was the usual case of moving the two towers into place and lifting this 130kg piece of structural roofing element up and swinging it along into place. We had to carve off a small chunk of wood at the steel I-Beam end of the rafter so it can avoid hitting the sticking out upper flange of the I-Beam but apart from that and being very tight indeed, it fitted quite well indeed!!

Now we can measure the final three special rafters and have them created, nothing complicated about them, just straight and we will get them done in quick time!

We spent the day inside our workshop to avoid more rain. It has been quite wet these last few days and we are having to do other work while we wait for better weather to arrive. So in our workshop, we did several different things. Firstly, we repaired the hood over the circular saw blade that serves both as a safety net against fingers touching the spinning blade, and the hood to act as a vacuum collection chamber to remove the sawdust.

We improved on the previous design to have two arms instead of one, and also these multi-jointed arms are much stiffer, thus making the hood much more stable and won’t bounce around anymore.

The second task we did, was to slice up all the remaining sheets of the polystyrene foam into lots of strips with width of 250mm.

We are about 25% through slicing each block into the required 38mm thick strips. We did this job because the weather got bad again and we didn’t want to get our plywood boards wet sitting on the trolley outside the workshop doors as we pass each sheet through the circular saw, so we switched over to do the foam boards instead.

Today, we tidied up the two sections of the O Ridge rafter by running the power planer along all the edges, the top and bottom edges. This made sure that they were fresh and clean as possible, ready for the gluing and bolting on of the steel strips.
Then dragging out half the workshop tools (well it seems so!) and brought out our two sections of the rafter and laid them on trestle legs. We proceeded to drill the eight bolt holes on around the steel elbow bracket and bolted the two plates together. While this was done, we took the two 6 metre steel strips and bent them at the required 45 degrees angles and drilled and bolted those two strips on too.
After a quick lunch (as there was rain forecast to come in the middle of the afternoon), we then unbolted the two big plates off and, after cleaning the metalwork with orange oil cleaning cloth, spread glue all over the surfaces (both the metal and wood) and re-bolted them back on again. The next job was to take off each edge strip one at a time to clean them and apply glue and again bolted it all back together. Nice and tight this time!
Finally, we got out the metal primer paint to quickly cover up the bare metal strips to protect them against rust while it is still exposed. Thank goodness that this paint dries very fast indeed!

We dashed back indoors with all our tools, electric cable and bits and pieces and just made it before the heavier rain came down!! That was close!! Grin!

This morning, we resumed our work on the O Ridge Rafter. The first part (the horizontal Ridge section) was vacuumed and then glued and nailed together. Then the second part (the 45 degrees angled section) was cut, sliced and adjusted for all the bits and pieces and after lunch, was sanded and vacuumed and again, glued and nailed together.

Having done that job nice and quick, we had time to take our other rafter, namely the one going into the LM corner, and take it outside to install it into position. The end results was a clean and neat job without fuss! Yippee!

Tomorrow, we will take out the two sections of the O Ridge and start assembling it with the metal elbow joint and the two metal strips on the top and bottom edges, hopefully the thunderstorm weather front will keep away as promised by the forecasters!! Smile!