Sunday, September 30, 2012

Aluminium raised seam roofing goes on

30 Sept 2012: [Extension] I'm lucky to have Henry on Sunday for another half a day, because we both had to go elsewhere at lunchtime, but that helped us to work faster as we had a deadline to work to. We've managed to run out of all materials, no more roofing felt left, and all aluminium used up! The roof is now watertight without needing a tarpaulin. 
At the start of the day, the extension is felted at the east and west walls and across the roof. The scaffolding above will be needed for the amendment to the Surya Sunbox.This is the view of the house for the walkers passing the house. It is a 'stealth extension' !
Time to get started with cutting. The first sheet takes the longest time - we are nervous about it, and you always have to think of the first one as the 'research' workpiece. We had our cardboard template that was near enough perfect - only the smallest mods were required. We have cut both sides of the sheet according to the template. The blue colour is the protective plastic covering the metal. The 0.7mm sheet is easy to cut with a power tool, and is also very easy to cut with a hand tool. 
Now getting ready to FOLD. We have bent test pieces, but this is the real thing. It's time to feel how stiff it will be, and whether we get a nice sharp corner. The sheet has to be clamped along its entire length.First fold 'Male' went well, so now the second and larger fold has also been done. This is the 'Female' side and the final welt will be done when the tray is set into its place between the angles. We are using a much stouter piece of plywood for the hard edge, and one can put one's knee on the ply, so that the grip is very firm - and use a rubber mallet to beat the metal into place.
Henry carries the first aluminium tray to the scaffolding to fit into its place. It was a windy day, so gloves are advisable in case the sheet is blown in a gust.It fits! the tray is a perfect fit, with enough space for thermal expansion from summer to winter thermal difference. It won't get massively hot in summer because it is reflective, and most of it will be covered with the solar panels. 
The remaining metal trays are produced with great speed now that we have established a good working method.The abutment fold is also done, and there is enough sheet left to make a small securing tab to maintain the tray shape. This might well be riveted when it is finalised.
Henry is considering the welting process. We found the 'male' part to be up too high above the angle top by about 5mm, so we had to decide whether to cut it back or beat it down…. beating won.The three main trays are in place, and it's now time to make the end panels for the verges. There is only enough aluminium to make one, so we make the east end, and I will order another sheet for the west end.
Henry works his way up the seam, beating the up-facing edge to the left and downwards so that the seam angle is well gripped.The rubber mallet is about 37 years old, still doing a good job. I've hand-built a house extension to every house I have lived in (in Nottingham), and this is the latest in the line.
We are using 1metre wide sheets, so the seam spacing is precisely 900mm. 100mm is the sum total of the male and female parts of the welting detail. The three middle trays are 895mm wide, so there is a comfortable fit. The extension is exactly 3600mm long, so the end trays are 450mm each.It's nearly lunchtime so it's time to go, but the extension is now well weatherproofed. the little white pipe in the distant panel is actually a conduit into the room below so that we can draw a cable through from the loft. We intend to have a 12v lighting system.
Another task is to build the vertical duct that comes from the loft down to the extension roof. Its a lot easier to build this with all the scaffolding up, instead of having to climb a ladder. The metal hook has been there for a while, it was put up to give me a safety point for when I go up the ladder. Two 22mm holes are now drilled. They are diagonally related, as a horizontal pipe run in the loft has to convert to a vertical pipe run in the duct. I started drilling a hole next to the first, then remembered the need to 'mitre' the joint.
At Sunday sunset, it's looking good. The scaffolding and garden can be tidied of scrap wood, tools, tarpaulins, bits of insulation etc.
Some people have asked for a drawing of the raised seam.... here it is!

September 2012 Reports

For those just arrived, this news item is updated each week with any regular reports on performance of the systems in the Peveril Solar house, notably the annual consumption and generation figures. There has been no heating requirement since April / May, and the only demand on the heat pump is hot water use, that has little variation unless we have people staying to use more water - not often. Until the winter restarts, it seems that the system has settled down to a House consumption of about 5,030 kWh and a GSHP consumption of 2,985 kWh. It will get worse when the heating season starts.

30 Sept: It's been week-one at the University, so not a lot done on the extension until the weekend when my son Henry visited for a day and a half of labour, getting the roof felted and metalled. In the rest of the world... the Brits were wondering what happened to the missing school teacher-pupil duo Forrest and Stammers, but they turned up in Bordeaux. For the annual figures for the Peveril Solar house:
House meter: 5,133 kWh. GSHP meter: 3,085 kWh. PV meter 3,050 kWh. I feel sad that the GSHP has passed the PV, in an unpleasant direction, but I have to take the long view. Averaged over three years, the PV figure I am aiming for is 3,333 kWh (see another article explaining that), and for the GSHP, the annual figure is going up because the 2011 heating season did not start till mid October, a full month after the start-date in 2012 - I just hope that it doesn't get to 3,333. The ground temperature is looking OK at 12.6º, helped by a sunny saturday during the week.

23 Sept 2012: Another grey week, although good progress has been made on the house extension. The heating season began with a run of days with some below-10º temperatures, blowing all my annual figures into a bad place, considering that in 2011 the heating season didn't start until October 16.
For the Peveril Solar house, in kilowatt hours per annum:
House meter annual 5,089 (5,189 over 2 yrs), GSHP 3,039 (3,166 over 2 yrs), PV 3,177 (3,196 over 2 yrs). The Sunbox is at 2,589 (it's a long climb back to the days of being above 3,000 all the time). At the end of a cool week, and the heating back on, the ground temperature bounced downwards to 12.5º.
In the outside world, the shooting of two female police officers in Manchester took most of the headlines, and as a surrealistic follow up, the Tory chief whip Andrew Mitchell is in trouble for using a lot of abusive public school boy language towards a female police officer in Downing St only 33 hours after the shooting. The US election campaign rolls on, and I give thanks that Romney's campaign appears to be sinking with team members quitting after the video revelations about the '47%' of welfare scrounging democrats, and consequent criticisms even from conservative media like Fox.

16 Sept 2012: The week has been greyer weather, and despite a small amount of time lost to rain, we got the extension built and the roof on, and more or less watertight. But we need to wait until next month for the windows, so the openings are presently boarded up.  In other parts of the world, the 11 Sept anniversary passed of quietly in New York but with extreme violence in other parts of the world with the US consulate in Benghazi attacked with rocket launchers (killing the US ambassador) and copycat attacks in Cairo, Yemen and Khartoum, and even in London - linked ostensibly to a Youtube movie mocking Mohamed that was made by a convicted fraudster who is breaking parole by having access to the internet with a false name - funded by Xtian fundamentalists. What else?... Andy Murray delighted millions by being the first Brit to win a grand Slam in 76 years! He ended a great year of achievement with a Wimbledon Final, the Olympic Gold medal and winning the US open. The British public were outraged that french paparazzi had photographed Princess Kate sunbathing topless in a very private location in Provence. As there is no public interest in this (compared with similar toe-sucking photos of Fergie), the photographers deserve to be sued for all that the Cambridges can take them for. The Hillsborough enquiry found that there had been evidence of Yorkshire police guilt at the time and in a later cover-up, and exonerated the suffering Liverpool fans.
   What about the Peveril Solar house? Well the figures are much the same, as we haven't turned on the heating yet. We were on holiday a year ago, and so the figures worsen briefly. The GSHP is just scraping under the line at 2,999 kWh. The ground temperature is 13.5ºC, after a week of not much sunshine, although PV figures are looking better at 3,194 kWh.

9 Sept 2012: After a week of working on the house extension, and sunny weather almost every day, our annual figures are at last beginning to improve noticeably.
House and Heat pump are holding steady because it is summer. The PV figures have risen to 3,101kWh, a welcome improvement.
In other places, it was the week of the Democratic Convention, with Clinton, Michelle Obama, Biden, and the President himself all making good speeches.  In France, near Annecy, there was a very scary 'hitman' type murder of a British family in their car. It was the final week of the Paralympics, and more medals have been won by British athletes than ever before. The night closed with a wonderful closing ceremony.

2 Sept 2012: August ended on a good note of improving weather, and September is bringing the summer that we didn't have earlier.

Extension felt very good

29 Sept 2012: [Extension] Son Henry has turned up for the weekend to give us a working Saturday and Sunday morning and we have made good progress. The extension is now felted, roof and side walls, although we didn't have enough to complete the south facing walls. We are beginning work on the aluminium raised seam roofing.

Before the roof is felted over we do a very taping over of every roof-seam and nylon bolt, with external quality duct tape. We run the circular saw along the eaves board to make sure that it is perfectly straight and even.The gap between the roof and wall has been filled with expanding foam and the surplus is cut away level with the roof deck. We have one red brick course for the roof upstand and the flashing (which will fit under the blue brick).
Henry's busy getting the details right before we fasten down the felt. Small gaps at the top of the wall between the wall and the roof deck are filled in with compressible foam, then taped over to make them airtight.That edge work is done, and a final aluminium connecting bracket is fitted. This baby isn't going to fly away in a strong wind!
Before fastening down the felt, we remember that it's better to groove out the mortar just below the blue brick course now. If we do it later, the brick and sand dust will ruin our lovely aluminium sheet roofing. So the heavy duty masonry blade is fitted to the angle grinder.We were right - a helluva lot of abrasive dust is created, and it is an unpleasant job needing goggles and a breathing mask. We now have a very good 10mm gap about 25mm deep, which is enough for me to insert a lead flashing in a bed of resin, sometime in the future.
Another job that is needed is a small conduit from the solar panel into the room below, so we can have a 12volt DC lighting system in the extension, running off the future batteries. Don't worry, the rain will come down the conduit, there will be a vertical aluminium duct here for the solar thermal pipes from our PVT panels.The moment arrives when we can fasten down the first large sheet of roofing felt on the roof. Later we are going to fit the aluminium roofing and it is vital to know where the nylon bolts and aluminium connecting plates are.
We have devised a dry welting detail for the eaves and here goes, this is the first clout nail going in to confirm our decision.The long felt is lined up with the edge of the board, and another 200mm strip is worked in along the eaves. It's tucked under the main felt, and then wrapped around and under the roof deck and secured.
At the top edge, the felt is brought up to the underside of the blue brick. We've had to tailor it around the vertical conduit. the centreline chalk line indicates the centre of the roof, as a guide to fitting the upstanding seams.The standing seams are being prepared after dark, all based on 40x40x3mm aluminium angle.
During dinner, we are thinking about the cutting details for the aluminium 0.7mm sheets that will go between the seams. They will be like stiff trays with upstand and downstand at the end details, and a welted detail along the roofline, finally fixed with rivets along the seams and along the eaves detail.The template is now finished, so in the morning, we will be able to cut each sheet accurately.

Saturday, September 29, 2012

Work starts on the solar shader

28 Sept 2012: The work on enclosing the extension is the main task, but other work has to be done too. This is the start of work on the triple louvre solar shader. This will be over the main south window. The window is a thermal window, meaning that it can gain more heat than it loses. Clearly, this isnt completely desirable in the height of Summer, so a solar shader is a good device to fit.
    Dave Oliver (of our department), a metals engineer, is routing out an 80mm long slotted hole in the cantilevering arm. This is part of a friction hinge design for a 'Yielding cantilever' whereby if someone reaches up and tries to hang from it, the shader will yield gracefully, lowering… and can be pushed back into place. 

Dave has a digital router, that can work metal to accuracy of thousandths of a millimetre - slightly more than I need for this, but a lot better than I could do in my garage with the angle grinder. Close up, the cutting head is subjected to a continuous flow of water to cool the cutting head and to assist in the cutting action. 

Thursday, September 27, 2012

Holscot ETFE and Charred Cedar


27 Sept 2012: [Extension] The Holscot replacement ETFE frames for the Surya Sunbox have arrived, and are still in their packaging. It's best not to open them until I am ready to make an outer frame as there is a risk of damage if they are unpacked too early.


Another development is further thinking about the wall cladding. All along I have been thinking of some hi-tech finish, in particular Trespa board which is a thin, durable composite board with a wide choice of print finishes, including wood finishes. I have been put off real wood by the risk of maintenance tasks. However, there is a fashion for charred Cedar which is very durable and said to be maintenance free, and it is easily fastened with self tapping screws. However, it is difficult to find a supplier - most of the Grand Designs examples have people doing it themselves with a blowlamp or wood fire. On the campus, my department has been building a house clad with charred cedar, and all the sidings are vertical, leaving an abundance of offcuts, because they try to avoid a joint in the wood. So I am going to try to save a roofrack load from being put in a skip, and see if they will fit our extension. Only 14.4 sqm are needed, and my longest length would be 1.45m if I run them horizontally.

Extension, quiet progress

27 Sept 2012: [Extension] I've been quiet for a while, as the University term has started and we have things to do there, but also, it has been raining on and off from Sunday afternoon to Wednesday evening. It is a lovely sunny day on Thursday, but DOH! I have to read more dissertations by the end of the day.

A few small things have been done.
  • I have started work on putting roofing felt around the exterior. This will be on walls and roof.
  • I have foamed up the gap between the extension roof and wall, and the east wall and brick wall where there was a gap. 
  • The brick/block opening below the lintel wasn't quite plumb, so this has been straightened up with a bit of filler. 
  • Paid the second half of the invoice for the windows installation, as this is now in the UK.
  • I've been reading up on plastering and plasterboard and dab (including Youtube training videos) and feel pretty well up to doing this, although I need to invest in a few additional tools, like a plaster stirrer, plasterer's saw and rasp, and a new Stanley knife. 
The black felt is going on, but I must not forget where the nylon bolts are, in case I try to drill or nail into them. These locations are being chalked on as the felt goes up. Another bottle of squirty foam goes into the remaining gaps where the blue and red bricks alternative. There is a minimal amount of 'ooze' which is easily cut away with a plasterer's tool.

Monday, September 24, 2012

Scaffolding, fixings and rain

23 Sept 2012: [Extension]  The Sunday started with an early knock on the door and Richard Pearson arriving to put up the scaffolding. I am really grateful to him for this as he has a full order book for the week, and wouldn't have been able to do our house until next Saturday. I don't want to lose a whole week's work.

Richard getting to work. He has to build a tower either side of the extension and form a bridge across with a walkable deck, and another deck for the extension roof. Verticals going up on a Sunday morning... just before the rains come down.
Nearly done! It is a complex 3D geometry, but somehow he has a design and is able to build the most economical structure.
PS shortly after this was photographed, we had a continuous 24 hours of rain, but with the tarpaulin up there, and the shelter from the scaffold boards, not a single drip or drop came into the extension!
Meanwhile, I do more on the interior, putting connecting plates between the panels and roof cassettes. Also, I have started the small bit of flat ceiling up by the roof connection to the wall, and will stuff more newspapers etc in there, in a weather proof bag for future generations. Every possible hole or crack is being taped up from within, and I shall use external quality duct tape on the outside, if it would only stop raining!

Sunday, September 23, 2012

Records will be broken... in the wrong direction :(

22 Sept 2012: The heating season has started already, with two cold days this week. I've been looking at the metering records and in 2011, the heating was not needed until mid-October. During 2011, almost every week, the metering results seemed to be setting new records, and yes, they were. transitioning from a cold to a warm year, you get some amazingly quick improvements in annual performance.
  2010 was an shiveringly cold year with a stiff winter period at each end, and the heating season starting in September. Conversely, 2011 was stupidly warm with no winter periods, double figure temperatures in January, sunny spring and light autumnal weather lasting right through to mid December. Weather like that cannot last... and it has not, we have been punished in 2012 with record rainfall and cloudiness.
   I have to accept that in the autumn of this year of 2012, transitioning from a warm to a cold year, the figures for annual consumption will go higher than I would like.
   The new target is that the GSHP consumption should still be lower than the best or a high average achieved by the PV roof. That was 3,450 kWh earlier in the year, and has averaged 3,300 kWh since the PV panels were installed. The GSHP consumption will go above 3,000 this week, but I am 'desperately hoping' that it will remain below both of those two PV figures - it's needed for me to continue to claim 'Net-Zero' status.

Structural strengthening with brackets

22 Sept 2012: [Extension]  A nice sunny day, and a small amount of progress was made, mainly in making small brackets in aluminium to hold the structure together - which until now has enjoyed the benefits of Gravity, and henceforth is properly stitched together. My original idea was aluminium strip on all seams and corners, but this seems a bit over the top. One function of the aluminium was to make it airtight, but I have discovered the magic properties of aluminium foil tape, and it is sufficient for airtightness to tape every joint. Structurally, it is sufficient to have angles in some places, but to have brackets in less critical places. All the angles will be covered either with plasterboard or rain screen cladding, so looks do not come into it.

Some 105º angle brackets are required, so the easiest method is to make these from 1.2mm aluminium… you will not find these in B&Q!105º brackets now made, and some had to be made at 75º too, for the roof junction with its wall plate.
Earlier seams in the construction were over structured with continuous strip, but they can stay now. I can save aluminium by using smaller plates and brackets in future, and relying on the special metal tape for the airtightness - here you can see it has been put on every nylon bolt-head. The roof is still a large tarpaulin, held on with clamps.Some stronger brackets in 3mm aluminium are used for securing the roof panels to the gable walls. 
I have run out of the metal tape and must go to Screwfix in the morning - tape will be continuous on all joints. But I have taped where all the brackets are going, and a group of brackets are illustrated here. 

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