Slapping down our last window – the inside

We have one more window to open up, the only one that we have to make in an existing wall that we cannot open up from the wallhead. We planned it in two parts:

• Firstly to open up the inside of the wall, insert concrete blocks to form the sides, then dig out above to install two concrete structural lintels and support the wall.
• Secondly to repeat the process on the outside of the wall, quoin stones each side then a concrete lintel and the decorative granite lintel above. We will probably notch the quoin stones 25mm or so, so that we can slide a granite sill in place afterwards.

The first part went as planned. I marked out the window with spray paint, then dug out rubble up the left side to at least half the depth of the wall. I used a cement mortar and built concrete blocks up to form the left side of the window opening. Then the same up the right side. Digging out the stones above the window was a lot more problematic. There were two big stones from the front face that went well over to the inside wall, there was no way I could get them out without knocking right through. So I got the rotary hammer out, drilled holes across the stones and used the feathers & tare set to split them. It was a bit of a fiddle, but they did the job. It was fairly straightforwards after that – I made up a dryish cement/lime mix, set up the chain hoist on the joists of the roof trusses and lifted the lintels into place, packing mortar above them as they went in.

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Powder Coating

Having decided on timber windows with powder-coated aluminium exteriors, it was not a big leap to then think about powder-coated
fascia boards. We even have a RAL colour. We drew up shortlists, took the ones that we both agreed on and haggled down to – 6004 blue green. As an aside, do not look for RAL colours online. What with different rendering between devices and poor translation from RAL to RGB/CMYK, it is inconsistent & misleading. We bought a physical RAL K7 Classic colour swatch and were aghast at the difference.

We need to be able to handle chunky lengths of aluminium around 2m long. Ric has specced out a design for a) an oven that will cook them at 180c and b) a bending machine . We will start ordering stuff as soon as we get on site in April. For the oven, we need…

• 0.7mm aluminium sheets 1250 x 2500 to form the oven casing
• 100mm loft insulation to insulate the oven
• strapping to hold the insulation in place
• a 2kW heater and a fan, to heat the oven & spread the heat
• a PID temperature controller and associated bits, to regulate the temperature
• a thermometer, to go at the other end of the oven from the controller, to show when the whole oven is at temperature
• a ‘D’ format kettle lead and connector
• cables, screws etc. to construct the oven and wire in the electrics
• fencing wire, to suspend the aluminium inside the oven as it cooks

The folding machine has a fixed part that the sheet of aluminium is held on and a moving part that pivots round 90 degrees, to bend the aluminium round a sharp angle. It is a fairly standard bit of workshop kit, but ours will be larger than average. We need…

• a 2.7m length of 127x76x13 I beam (UB) for the piece that pivots up
• a 2.7m length of 203x102x23 I beam (UB) for the piece that holds the sheet in place
• a 2.7m length of 75x75x8mm angle to fold the sheet around
• 4 lengths of scaffolding tube to use as legs
• weld-on hinges to attach the two lengths of I beam together i.e. to create the pivot point
• bolts to hold it together

We will probably use 0.5mm aluminium sheeting for the fascia and 0.7mm for the windows. The primer and powder coating both come in handy 20kg packs – we might just get away with one of each. We will doubtless have to improvise a bit to get the whole thing working.

Whilst on aluminium sheet, we have changed our minds on heating the up-stairs areas of the steading. The building warrant expects us to use radiators, we now want under-floor heating. The only practical way to do this without using up room height is to use aluminium spreader plates under the floor boards, with 50mm PIR insulation under the plates. However, commercially-manufactured plates are not designed for using heat pumps (35c water, requiring 100mm pipe spacing) on floors with joists at 600mm centres. We reckon we can make our own, more cheaply than getting someone else to make them up for us as a ‘special’. We are not sure whether we will need a separate folding machine.

More on timber for windows and floors

We discovered the website of the Association of Scottish Hardwood Sawmillers (http://www.ashs.co.uk/) back in September and I picked through it, for a round half-dozen possible suppliers of timber for windows. I emailed each supplier, explaining what I wanted. I had a quick response back from one of them, to say that he had sold his business and had moved to Devon, but he gave me the contact details for his successor, who I also emailed. Other than that, it all went quiet for a week or two. I had expected that I would need to phone up and chivvy them along.

I did get a response, un-prompted, from Abbey Timber, near Duns in the Scottish borders. They suggested ash at £1200+VAT per cubic metre or douglas fir at £700+VAT per cubic metre. This sets a very handy base price of c. £5,000 or £3,000 respectively, for all our windows and doors. This is quite a bit better than the £6,000 or so that we were expecting and ash is one of my preferences anyway. The douglas fir proposal was a bit left-field for me, I checked with Ric and he was positive about it.

It also made us think more about solid timber flooring. We decided early on that the ground floor would be tiles (kitchen area and bathrooms) and engineered hardwood boards. The latter being more stable with underfloor heating than solid timber. Upstairs, where we expect to have radiators, we decided on carpets over chipboard panelling. In which case we would not be looking around for solid wood flooring. I factored all this into my costings and had allowed no more than £30 per square metre, average, for floor coverings.

We discuss with Ric the pros & cons of timber flooring upstairs, over the summer – he was enthusiastic, I was wary about adding cost. Thinking more about it, I conclude that I had assumed that solid timber would have to mean hardwood and that it would be too pricy. In fact douglas fir makes very good flooring and we could keep within the £30psm limit even with comparatively luxurious 1” (25mm) planking. On looking at the Abbey Timber website, I see they do prepared 25mm T&G planking from £24+VATpsm. So that is a definite possibility.

To further muddy the water, Ric suggested using underfloor heating upstairs, with solid wood floors. He gave us tips to ensure that it does not go horribly wrong, including using thinner planking. This would, of course, apply equally to downstairs. So Abbey Timber do hardwood flooring starting at £28+VATpsm. I looked at engineered timber prices and was a bit surprised/shocked that whilst you can get (3-strip) boards at £27incVATpsm, single-strip boards are nearer £40incVATpsm upwards.

So my assumptions that solid wood was not affordable downstairs may be wrong. Because we will use a heat pump, our heating water will never be above 35c and will run most of the time, so we would not expect problems with wood warping due to the heating.

So yes, it is all up in the air…

We need to prepare for windows

With our roof starting to take shape, we need to think about doors and windows. We would like to make our own.

This might seems a bit cranky, but there are big plusses for us. We want wooden windows/doors with powder-coated aluminium on the outside. We can choose the species of wood and we think we can create a big enough oven to powder-coat largeish bits of aluminium. Powder-coating is readily available in a bewildering array of RAL colours. We want windows with a single (probably top-opening) casement & our big 3m x 3m window will not have casements but will be in three vertical sections, each with one horizontal bar i.e. it will be like 6 smaller windows. Ric has a piece of equipment that he can ship up that will thickness-plane timber and has a spindle moulder. Ric would make some of the windows and then train us up to carry on. We can make the wooden shutters we want to use in place of curtains (downstairs, at least) and we are not interested in the current fashion for really skinny window frames. We can buy the grade of sealed units, opening mechanisms and door furniture we want – subject to meeting standards of course. It may also work out cheaper than buying made-to-measure windows – none of our openings are any sort of standard size.

We would not be interested in making our own roof lights – they will be comparative invisible and are more technically challenging to make weather-proof.

We had a look at suppliers of Scottish Hardwood, there are quite a few of them (although some sell more generic UK-sourced wood) and we got a bit of a feel for prices. Typically oak and beech are at the higher end, with ash, lime and larch at the lower end. Ric converted our list of windows and doors into a spreadsheet of timbers, large enough to allow for machining down to size. Most of the window frames will need 125mm x 100mm timber (uncut dimensions) and 75mm x 75mm for the casements. The big window would need 200mm x 100mm timbers, to provide the strength to resist strong winds. We would use 200mm x 65mm timber for the doors and 150mm x 35mm timber for the frames.

Anyway, we would need lots of timber, more than 200 pieces, which amount to 3.24 cubic metres or 114 cubic feet. We need to contact a few suppliers and get guide prices for different types of timber…

Truss preparation – quoin stones

We did not make good progress on getting the north wing ready for roof trusses, whilst we were on site. We lost a couple of working days due to windy weather. Of the three windows that need building up, so we can complete the wallhead, we got three courses of stone in one window, 1-2 stones each side short of lintel height. After that there is the front door that needs a lot of work.

Decisions, decisions!

All of a sudden we are faced with two tangible and, for us, exciting questions that are not about things hidden underground and that we hope to never see again.

So…

1 – do we work on roofs, doors, windows and walling for the whole steading, or on one wing at a time?

By splitting the work into three tasks, we could roof and fit out each wing separately as well. The main pro was that we could move into the first completed wing early, lose the caravan and work on the rest of the site in relative comfort. We would have indoor and outdoor jobs. Without the caravan, we could work on the courtyard and break the hardstandings on the east side, getting set up for our polytunnel and veg plot. It would also clearly break the work up into smaller and more manageable units and we could spread our spending more evenly. The potential con is that we would have to buy the roof trusses in three sections, which might cost a bit more overall. Similarly with the floor screed which we intended to be gypsum-based, self-levelling and thinner than a concrete screed. If we are not pushed for height, we could go back to the idea of the concrete screed and DIY.

The decision was easy, we will split the work up. Ric’s view was that the east wing would be easiest and quickest to start on. This again suits us fine, it has more rooms and the main bathroom.

At a practical level, we will need to run services temporarily into the east wing, given that our main plant room is intended to be next to the front door, right up the opposite end of the north wing. We would install under-floor heating but could not use it until we have the thermal store and one of the air-source heat pump or woodburner installed and commissioned. Given the high level of insulation and draft proofing, it should be fairly easy to heat to a satisfactory level using portable electric heaters. We briefly discussed getting electricity in – we could install a consumer unit in east and west wings, getting each wing fully wired as we went. We might want to move the outside meter a few metres northwards along the west-facing wall and recess it into the ex-garage wall, then run the service cable into the garage area and split it in three, with one distribution cable for each consumer unit.

2 – The aesthetics of our doors and windows

Given we acquired a mass of quoin stones from Mr Aitken next door, which are a mix of red and grey granite, how do we use these to best effect? Our bothy has red and grey quoins and it works (surprisingly) well. We will think more about this once we are up, in the meantime Ric will sort the stones into colours and shapes – some are angled back to create splayed window reveals that will soften the daylight on bright days and spread it sideways. On a related point, we already have some splayed windows, so the lintels on the inside edge of the wall need to be longer than those nearer the front. Ric asked whether I had taken account of this when I ordered concrete structural lintels. The short answer being, No. I hope/expect there is enough slack in what we have on site. For example, the batch we just had delivered have not been cut to size yet.

The other aesthetic consideration is around the window frames to be installed. We had always agreed with the architect that we would use powder-coated aluminium-clad wooden windows and doors. Ric suggested he could make at least the windows, with the provisio that they would not look as factory-made as commercial windows – there would be a little variation due to them being hand-made. Again, we will think about it and discuss once we are up there.