This afternoon, after a interruption to our work flow due to other meetings, we first went outside to verify the measurements we made last week on the “N” section and updated our spreadsheet. We then started the preparation job for building the next batch of rafters, this time for the “N” section of the roof. Using the new updated spreadsheet (showing the calculations as a result of our verification task earlier) and proceeded to slice and chop up a half a dozen of CLS timber to go towards the heap of material we will need for making another eight more rafters.
Category: Phase 4
Construction of External Skin of House: External Walls, Roof and Skylight. Slate tiles on roof and timber cladding on walls.
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“N” Rafter Installed and Measurements taken for “N” and “O” secitons
This afternoon, while we had some nice weather, even though it was quite chilly, we went and got our odd “N” rafter (the middle one, which is number 6) up and installed. We had to plane the end a fair bit as it was a complex shaped ends and we had wondered whether we had removed enough in the workshop. So it was a case of removing more until it fitted nice and tight.
We then measured the next subset of rafters on either side, these being the triangular sections going up to the steel I-Beam and down to the outside corner. These are now in our spreadsheet!
We did also the same for the “O” section and took measurements for the similar shaped triangular sections for the 45 degree sloping roof too.
We now have finally collected this data and we now have the means to continue working in the workshop while the weather is bad outside and try not to lose too much more time due to the weather!
We hope!
Grin! -
Oak Timber Arrives!
This afternoon, in the middle of our lunch hour (about 1:30pm), the Oak Timber arrived!! There were ten packs in total, in four stacks on the back of the lorry. Also, on the back of the lorry, was a fork-lift truck which came down two steep ramps off the end! We were lucky that the driver was confident to reverse the lorry back down our Loke and avoided causing major traffic hold-ups on the A143 Beccles Road !
Oak-Deilvery-First-Pallet-Unloading-
Oak-Deilvery-The-Forklift
The forklift the moved the packs to the cleared area by the Storage hut.
Oak-Deilvery-All-Delivered
The pallets were quite neatly organised, each one having the timber of similar dimensions so we could check off against what we ordered. The initial spot check seems to show that we have got a lot larger volume of Oak than stated on the delivery note. This doesn’t means that we got more planks of Oak, just more volume. And in fact, after processing three pallets, measuring every single one and moving them to our sheltered storage area, it seems that most planks are thicker than advertised!
Oak-Deilvery-First-3-packs-onto-rack
We had a cordless keyboard and a cordless speaker sitting outside on one of the shelves on the storage rack (connected to one of our desktop computers inside), and as each plank was measured using a digital calipers and steel rule, the data was typed into a spreadsheet and then moved and sorted on separate sections on the rack.
We will resume on Friday with the sorting out the other seven pallets and get all the data into the database so we can cross reference any piece and mark it as being used and record what left-over there is, to be used somewhere else in other parts of the house. -
Bevels Cut On Latest Rafters
This morning, while we wait for the delivery of our Oak Timber, we got on with the task of cutting angled bevelled ends on the latest batch of rafters we made yesterday.
These have quite a sharp angle, very deep, at 53° and almost 100mm deep. Our slicing Saw machine performed very well! And this second version which has a new electric motor on board, is a better quality unit and doesn’t get hot at all, only the gearbox! It is also much better at cutting the wood without burning the material as we are able to turn down the speed of the saw blade and that helps considerable in controlling this burning effect.
So we have now a growing pile of ready-to-install rafters to go up, all the remaining P rafters and one N rafter. We are just waiting for a day of no falling wetness, whether it is snow or rain! Phew! -
Created Four Rafters
Today and yesterday, we resumed our factory production line to produce the remaining rafters for completing the “P” section of the roof, as well as the first one of the “N” section.
It was amusing to see us racking our brains for all the steps of the procedure of making rafters, getting all the tools, equipment and glues out and get ready.
We finished today at about 4pm and it is snowing outside so that’s the end of our work for the moment!
We will see when we can get them up, weather permitting but also our Oak Timber is scheduled to arrive tomorrow too! -
Six “P” Rafters Go Up!
Before the rain arrived (about 3pm ) we got out there to get up and installed the six rafters we had made way back before Christmas, into the “P” section of the roof.
Rafters-P5-to-P10
These rafters were simple straight ones coming down from the O Ridge beam to the “P” wall, four of them had full eves sticking out and the last two didn’t.
Then after tidying up all our tools, under the steady patter of rain, we went and measured the last P4 rafter position so we can update the spreadsheet and then have the sizes for the last 4 rafters (P1 through to P4) to finish off the whole “P” section of the roof’s framework, covering the Great Room and alongside the conservatory.
We also measured on the other side for the middle rafter in the “N” section coming down from the O Ridge to the corner of the N and M walls. This particular rafter the only straight one in this group of rafters and it is situated in the metal bracket on the O Ridge so once that one is made and installed, we can measure alongside this rafter, on both sides, and get more measurements for the spreadsheet and we then can calculate what we would need to make the “N” rafters.
Finally, we returned back into the dry workshop and drilled bolt holes and sanded little slopes on the webbing so they can slide onto the leg and spread out the glue better. That concludes the work for today and the rain can do it worse. Hopefully, we can see dry weather tomorrow or else, we will be in the workshop and start preparing for those final P rafters! -
Bevel Ends Were Cut on P Rafters
This morning, a slight change of plan as the weather has come over wet again, so we got on with the job of cutting the bevel ends on the rafters going into the near corner of the Great Room near the front of the house. There were six in all, 5 were the full size rafters and the last one was just the top flange piece.
We dusted off the Slicing Saw Machine and got the template out of the shed and proceeded to slice the angled ends on these rafters.
And that is it for the day as the weather is now hailing frozen blobs of water so we will have an afternoon off and resume in the morning when we can start to put up these rafters and the others into place at last .. .. weather permitting!!! -
Glazing Framework Type, Shape and Size Final Adjustments
As a companion to the report Winter Cold Virus Hits the Workforce!, this blog describes the last two weeks of our building work.
so with the background noises of coughing, sniffing, sneezing and talking with croaky voices, we have been analysing the design of our Glazing Framework for the Skylight. We are thinking of reducing the number of glazing wooden rafters from the regular 600mm spacing to more like 1000mm instead. This would make the aspect of the skylight more pleasant to look at and to look through too. It would mean less physical number of elements to construct, assemble and install.Structural Analysis
But first, we had to analyse the structural requirements of our roof to make sure the glass can take the strain and loading of various weather conditions, like for example, a foot of snow or gale force winds, as specified in the Building Regulations for our easterly region. The result of that research was that our primary glazing layer needs to be 6mm toughened glass, spanning the 1200mm by 1000mm of support.
Size and Spacing
Next, we took each section of the Skylight in turn, to adjust the size of the glass so it is a regular spacing, for each room upstairs, taking into account the maximum we are allowed as per calculation of research we did, as follows:
- Great Room: 1 module – 1200mm and lots of triangular pieces
- Spare bedroom: 4 modules – 1011mm
- Hall & Stair: 2 modules – 813mm
- Study: 2 modules – 1008mm
- Workshop: 5 modules – 1061mm plus more triangular pieces
The other side of the skylight (where our solar electric collectors are located), starts with more triangles and a 1200mm section over the great room then a regular spacing of 917mm most of the way along the whole length, in 13 modules followed by a last few triangle pieces. This deliberate design choice allows us to fix and clamp the sloping wooden rafters right through the ridge beam for extra strength and security and allow
Thermal Properties
the solar panel modules to all the same size.
Another part of our analysis we have been doing, is the thermal properties of these glazing units, whether the cost of double or triple, or even quad glazing would payback and how quickly. Plus, the added complications of wear and tear to these sealed glazing units, during a hot and cold heat cycle and that causes physical stresses to the joints that seals the layers of the glass panes together. Thermal expansion is one of the most powerful forces out there and there is nothing anyone can do to stop it, apart from engineering the joints and seals to cope with the stress and strain of this physical effect.Summary
At this moment, the results of our research in heat loss, the weather conditions and thermal properties of the various glazing options, here is a summary (for the whole Skylight):
- Heat Loss: 12050 kWh per year using a 10 year historical data
- Energy Cost: £1205 per year with single glazing
- Double Glazing extra: £2000 to buy but Energy cost cuts dramatically to £140; payback time is 2 years!
- Triple Glazing: £3000 to buy; £85 per year for energy; 3 years payback time
- Quad Glazing: £4000 to buy; £60 per year; 4 years payback time.
NOTE: One aspect of this research that have not been included in these calculations, is the Solar Gain factor. This is a very powerful energy source and our Skylight is very large and will be collecting a great deal of solar energy during the daylight hours and we haven’t incorporated this into our calculations. But roughly, it will save us even more money and the payback time would reduce even further!These payback times are all based on a fresh start as the building is constructed, but it would be a completely different story if after 20 years, we have to replace the glazing units and it would be a pure fixed cost spread over the lifetime of the product. Everything fails eventually so one has to get into the frame of mind that we should be saving some money away in a piggy bank so we are ready for the replacement. Glazing units are now given a lifetime of 20 to 25 years so if it costs £4000 up front, then we need to put away £250 per year for 20 years, as no doubt the prices will rise too! eeek!
Our next job is to translate all this into a construction plans, building an order for materials and plan procedures etc. -
Oak Timber Ordered
We finalised and double checked our Oak Timber quantity and got a final quote from the timber merchant today.
The major difficulty we have is that the large quantity of the Oak timber, amassing to 6 cubic metres or about 5 tons of timber, needed some means of being off-loaded from the delivery truck and we don’t have an on-site forklift truck and also we are down at the end of an unadopted narrow lane too.
So we are having to pay for the hire of an lorry with all-terrain forklift vehicle, being transported alongside the Oak, from the merchants themselves. It is about £500 but that is less than 10% of the total order which is not so bad, and just something we have to accept as part of our building project’s overheads.
The timber will take about 2 weeks to come and we will do some site management and re-arrange piles of insulation boards and move them into the house and make a cleared area, ready to receive the Oak. -
“H” Section is Now Complete!
We finished off installing the rest of the “H” rafters outside, on quite a balmy day, on the shortest daylight day of the year!
Rafters-H13-to-H17-Installed
Rafters-H1-to-H5-Installed
Tomorrow, we will try and get some of the “P” rafters up before we have to stop for Christmas. We will see how things go and whether we will do some work on Saturday too.
