Paving and Setts - Part 1

It's been a long time since my last post.  At last the weather has improved, and I've been outside preparing to lay paving. The photo right shows what it used to be like soon after we bought it, and the photo below left shows the view from the other end when the extension was being rebuilt after removal of tons of earth (note higher garden on right).

This excavation gave a recessed pathway along beside the house, and I decided ages ago to put in a retaining wall about six feet from the house (photo below right, taken in opposite direction). 

This retaining wall is essential to prevent the higher ground of the "garden" (I like to call it that - it will be true one day!) moving gently back towards the house; this would again cause dampness and, having spent time and money in sorting this issue, I have no intention of ever letting it return.  However, as you can see, the wall is still not finished!

One of the issues in clearing up the exterior has been the question of what to lay?  For the same dampness reason I have not felt inclined to lay much concrete, or do anything which feels too permanent.  I will admit that I have laid concrete in the front, and just inside the back gates, but I felt this was a neccessary evil.  In the front it is three inches lower than it used to be and there's a recess beside the lounge wall, so I am not repeating the "let's concrete right up to the wall at interior floor height" error which caused floorboards and joists to rot.  Last year, for the back, I purchased some cast gratings which are really heavy duty items (in fact well over the top!); I intend to fit these between the house wall and whatever I do with the paving. 

It seems almost all paving is really quite expensive, but I have made it sound cheaper by comparing it to the cost of carpet.  You certainly get what you pay for; if it's cheap then it looks cheap and you'll regret it.  I did a fair search - cast cement, brick, reconstituted stone, real stone, etc, in a variety of colours and various finishes (but who wants polished stone outside?).  Eventually I found I could get imported tumbled limestone, 30mm thick in regular sizes, for £32 per square metre.  We chose the pale grey (with a faint hint of purple?) which hopefully will set off the greying yellow of the Cotswold limestone.

It seems the modern way is to lay a huge bed of cement, lay the paving of your choice and then add a dry mix for the grouting.  Something in me still rebels at the thought of laying paving on cement - it seems so permanent.  After all, in 2011 we got rid of nine 18-ton lorry loads of hardcore, soil and stuff from this house (and there were yards of concrete path and slabs all at the wrong height) so why should I want to lay more new cement?  So, after a lot of deliberation, I have gone for a dry bed of sand on MoT Type 1 hardcore (which was already laid in 2011). This has the benefit of being easily reversible (a key principle for old buildings) but requires to be held in place with solid edging.  [Top Tip - work out the entire cost before you decide anything - edging can add a lot to your costs, especially for some of those reconstituted stones.]  I decided to use granite setts which I could buy for about £2 each (and they are almost 25cm long); I am also saving a bit of cash and work by laying the sand up to the wall of the new extension (the level being two bricks below the DPC).  Since the extension was laid out with the use of a laser, this also gives me a good level to work from.

So, in the last three weeks I have laid the last little bit of concrete (near the drains) and a lot of setts in a slightly complicated pattern. This is because I didn't
want a straight pathway and, in any case, I have to avoid various obstacles such as the gas meter box and a few drains.  Clearly, you have to get the setts right: the right plan measurements to avoid cutting the slabs, and the right height as well.  The first thing I had to do, therefore, was to cut granite setts.  This is achieved by use of a bolster and a decent mallet; a few good blows with the bolster carefully held yield a pleasing result.  However, it is made more difficult if your setts are not smooth and then the bolster is not making good contact along its length.  Result - it splits in not quite the right direction!

The current situation is that I have finished the preparation along the side of the house.

The setts on the right will separate the paving from a strip of earth so that I can plant a few things to make the wall look pretty.  On the left, iron grating will fill the gap and allow the house wall to breathe.  Notice that the gas meter box is a bit high; this is a good indication of how much lower the ground level is now - when it was fitted it seemed ever so far down!  All I need to do is to work out how much Type 1 and sharp sand I need to order, then I can start laying.  Then I have to do the rear of the house and extension...

Now you see it, now you don't

They've gone and changed their minds; the operation is deferred for ages (even 12 months possibly), so I will after all be able to get on with the tasks that I want to do this summer.  When I said it was bad timing, I honestly didn't really want this to happen.

All I need now is some half decent weather to let me make a start outside.  The walls, pointing, edge setts and flagstones will all take ages, and I'd like to tidy up and sow some grass seed as well.  Then there's refurbishing sash windows - perhaps I'll get a couple done if I'm lucky this year - and repairing some stucco work at the front (although it's actually cement so shouldn't be too difficult).

In the meantime there is some decorating inside to be done, but that's a job I hate - removing the black gunge that the doors are coated with.  Sanding it just gums up the sandpaper in 15 or 20 seconds, and a heat gun requires three hands as you get these sticky dead slugs on your scraper which have to removed with a sharp knife or else all you do is to spread it around.  The other hassle with the heat gun is having to remove the smoke detectors as they tend to get set off by it.  I've never had much luck with paint remover but perhaps I'll give it another go. 

Bad Timing

I know my brother needs my kidney (see link on previous entry), but in many ways this really is bad timing.  I now have less than six weeks to do a whole load of work in the garden in order to get it ready for my convalescence.

I rather like the idea of sitting out in the summer sun for six or eight weeks, drinking a little lemonade and watching the birds feeding.  The plants will be growing nicely with a gentle fragrance filling the air, while swifts will be wheeling in the sky above.  The alert among you will have noticed the possibly erroneous assumption in all this: what summer?  We're into spring and even that refuses to work this year.  I certainly cannot do any lime brickwork while it's so cold, and I don't even really want to do any concreting or cement work while we're likely to get a frost at night.

I took delivery today of some granite setts which will act as one edge for my paving.  The other long edge is alongside the house; part will be a concrete strip which will support my cast iron grilles where I don't want to pave up to the wall of the old house. Where the paving goes up to the wall of the new extension I will have a strip of self-compacting gravel against the wall of the house as I don't mind that going a bit higher (and I don't have enough grilles!).  There is no point is replicating the earlier errors (of high ground against a porous wall) which I have permanently eliminated by spending a considerable amount.

Once I have done the edges, I can lay the flagstones.  These are on order at my favourite reclamation yard, and I think I've got him down to the lowest possible price of £32/sq m, which isn't bad if you say it quickly - mind you it is for proper 30mm thick real stone, not some thin reconstituted stuff.  I must admit that does sound expensive until you think how much good carpet costs; this stone will be around long after the carpet has given up.

If I can get these done before the operation, I'll be pretty happy, but if I can also clear and lay some lawn I'll be even happier! So, I have work to do as soon as I can persuade myself that the weather is (a) warm enough for me to work, and (b) warm enough for concrete to set properly.

All Quiet on the North Western Frontier

The garden to the west and north of my house is still technically not a garden but a builder's yard.  I made some progress with walls etc in last year's dismal apology for a summer, but I really want to get some major fine weather jobs done.  These include stone facing on a long retaining wall, 10 m of setts laid, 25 sq m of limestone pavers, a fair bit of earth removal, clearing the rubble from the "lawn", planting the new lawn, painting 16 m of picture rail for the lounge and refurbishing some of the 7 sash windows.  (Recently I turned a window cleaner away on the grounds that the state of the windows meant that he would be likely to damage them!)  Even recently I have been too busy with accounts to do much so the garden has been quiet for the entire winter.

However, all these best laid plans really have "gang agley".  I have an operation provisionally booked for May 1st, and so whatever is not done in the next six weeks will not get done until July or August.

I have been running a blog about this potential operation which you might care to visit: http://diaryofakidneydonor.blogspot.co.uk/. If you know of any one who has done something similar then please point them to it - I'd love to have details of people's recent experiences of this.  One thing that surprises me is that the whole thing now is VERY emotional - I can hardly talk or write about it without welling up.  I think this can only increase!

I'm glad I never actually set a completion date; we set (and met) the "move-in" date in July 2011, but thereafter it's just one task after another.  'Er indoors is very patient!!

Ze Flashing Lights!

Those of more mature years will remember the wonderful spoof TV comedy series "Allo! Allo!" from thirty odd years ago - I'm sure it's still shown on some Freeview channel somewhere (or else BBC will show it when they finish "Dad's Army" again).  It was all silliness about a cafe owner who was reluctantly involved with the French Resistance in WW2, in case you're wondering.  One of their running jokes was how the knobs on the elderly mother's bed flashed when "London" was calling "Night'awk"on the radio.

Why am I telling you this? Well, we have experienced the same sort of flashing lights over some period of time. The problem was usually associated with high winds (in my trees) and so it seemed to me to be something to do with the above ground cables which supply the mains electricity to all the houses here. The supply to our house is via a cable hung from the terraced house on one side, through the trees to the corner at the front left; there it splits and our feed goes left around the fascia while the feed for next door routes to the right along our fascia (old photo right; the cable is not visible but goes from the top left corner of the picture to a point above my head, level with the gutter).  I was misled by the same symptom happening to other people locally which caused me to believe that it was affecting a good number of houses.  When we moved in I had some interesting times with the electricity supply (which I mentioned in this entry) as the old cable was perished and totally covered by the ivy.  Although it took a fair few phone calls, the job did get done properly and so I thought it was unlikely that the flashing issue was with my end of the cable.

However, I got fed up with the flashing in the high winds a couple of weeks ago - it wasn't just the flashing, but the fact that it tripped our answerphone which then reset itself saying "Answer on; calls will be answered in five rings".  When the power dip is repetitive, you hear "Answer on - Answer on - Ans - Answer -Ans" etc which is really annoying when you know you are alone in the house.  Curiously the power issue only seemed to affect the phone.  No digital clocks reset themselves and there was no other symptom, until the day when (unusually) I had the digital radio on and it all went garbled for some time; it only came good when I switched it off and on.  Then later the same day it went off entirely for over a minute and I decided this was too much so called the electricity supplier.  Of course, I got cut off once making that call by the answerphone resetting itself!  Aaaaagh!

Anyway, at last the problem was reported and they promptly came with the emergency team.  To my surprise they reckoned there was indeed a problem with the new connection - it had overheated (WHY?) and melted the plastic sheathing.  Worryingly, they said that it did happen sometimes even with new bits (but I'm a Chartered Engineer and I like to know WHY!). It's been replaced now and the problem has not recurred, so tranquility rules again.

The Saga of the Water Meter

In almost every decision on restoring this house, I deliberately tended to adopt the long term solution.  After all, we expect to be living here for a fair while, so the more expensive long term solutions were always worth considering as we would derive the benefit.  One such was the sheepswool loft insulation (see this page); this was quite expensive but it allows the ceilings to breathe, and is so much nicer to work with than the glass stuff which irritates.  Another has been the acrylic secondary glazing (see this page), which has made the house so much more comfortable, and in any case will have paid for itself in two years or less.  Other investments are purely financial, based on the expectation that we will still own the house in ten or more years' time; one such item was the water meter.  We had one in our rented house in 2010, and the experience was that, with just two of us living there, the meter had saved us about £150 per year.  So it was a no-brainer to have one fitted here and, quite naturally, I wanted it done early in the restoration.

I had identified that the mains supply for the house had a stop cock under a plastic cover in the pavement; there were two stop cocks inside the house; the main one was in the hall and fed a flexible (washing machine quality?) pipe which went to the bathroom above and had supplied the cold tank (which had already been removed to the garden!).  The other supply went to the old extension, and I had had the plumber fit a new internal tap so that we could properly attach a hose for the plastering and floor laying.  When that was working I had the plumber feed the other supply through to the kitchen so that it was ready there, but out of the way of planned work.

So, early in 2011 I made an application to Thames Water for a meter.  They sent out a workman (actually a contractor) who looked at everything and asked me if I wanted an internal or external meter.  I said "external if possible", not wanting to have a meter getting in the way of the kitchen floor and plaster work about to be tackled.  Little did I know.  A crew was sent without delay, and they very speedily fitted a meter under the pavement.  OK so far!

There was an amusing small glitch later in the year - when doing the extension we found that the water supply in the old extension actually carried on under the brick wall separating our back gardens and fed our neighbour's outside tap.  This would not normally be a concern, but in fact it had been used as the sole supply for the construction of a £3 million building at the back; this was an arrangement which preceded the sale of next door, and when they purchased it, the builders had an obligation to pay his water bill for a period.  As it happens, the construction had been completed about two months before I asked for the meter, which was fortuitous.  My neighbour admitted that he had been puzzled that his water bill was completely normal!

Having moved in (July 2011), I had a very low bill the next month, followed in February 2012 by a quite reasonable one of £91 for a six month period.  You can imagine my consternation when in August 2012 I received my second six month bill for £274.  Now, the house next door (not our other half but a separate cottage) had been rented out from February 2012, having been empty for over a year; it was not difficult to do a quick bit of detective work and spot that there was no other water main cover in the pavement for 15 metres, and so clearly they had fitted the meter to a shared supply. D'oh!

I can write this now in the cool light of reflection of the last five months.  That time was regularly punctuated with me telephoning Thames Water and getting not much satisfaction.  It took a considerable amount of persistence to resolve this issue, and their first level help desk staff became predictable in their complete lack of ability to achieve anything.   Their typical response was to say that someone would call in 6 working days but nothing happened.  One really stupid thing that someone did was to rescind all their bills back to when the meter was fitted (although the meter readings WERE valid and acceptable to me for almost a year), and then send out a bill for the standard rate for April 2011 to April 2013, so that I owed them £789, payable at once!

If you have the same sort of issue, my top tip is that at the first excuse you say the magic words "I want to escalate this issue".  Once I had been passed on to the "Escalation Department" I had much better service and progress was made, ultimately successfully.  Sadly for me that did not happen until I had wasted nine weeks and many phone calls in trying.  A second top tip is to keep a good record of your phone calls; it really gets the attention of the Manager in the "Escalation Department" when you can name the idiot who failed to do what he promised four months ago, and when you give a string of names and dates they quickly realize that you do indeed have a point.  The other thing to remember is that it is (usually) not the fault of the person to whom you are speaking, but one of their colleagues, so a plaintive sob story with a hint of desperation gets a far better response than shouting at the poor unfortunate one who was unlucky enough to get your call.

The result for me was that in order to have a meter it had to be internal.  Of course, this would have been much easier if it had been done before installing our new kitchen (June 2011), so there was a bit of an issue as to where to put it.  The only sensible place was under the sink, and Thames Water said that their installer needed six inches "all the way around" to fit the meter.  Now, it is natural to fit pipes within two inches of the wall and floor, isn't it?  This is what my plumber had done, and they wanted me to sort out the pipes before they would send someone to fit the meter.  I rather griped at that generous use of space which would have used the entire space underneath my sink for just the meter, and asked if my plumber could fit the meter as well.  This did not seem to be allowable, but they sent a man to look at the possibilities; he actually brought a meter with him, which somehow I persuaded him to leave and I then paid my plumber £96 to fit it right at the back of  the sink cupboard.  Good job!  All up and running.

I have today received their latest bill and I'm £165 in credit.  They wouldn't pay my £96 but the nice young woman has used a low figure for estimating the consumption if I'd had a meter which gave valid readings.  This has (deliberately or inadvertently?) given that sum back to me, so I'll let that drop, as I am really fed up with phoning their hepdesk!

Little Bits of Progress

It's really cold outside right now, so you won't be surprised at my lack of activity out there, even before it snowed.  All I can manage is an occasional quick foray to feed the birds or to bring in some more wood for the lounge fire - it seems to us that this fire is producing more heat into the room than last winter, but perhaps that's just us being older? We're still burning the trees from the front garden and the (untreated) old battens off the roof - I think that will see us into next winter fairly comfortably.  There is a nice feeling of burning fuel that actually cost us nothing as the battens would have gone to landfill if I had left them for the roofers to get rid of; the only cost of the trees was that the tree-fellers had to do a few more strokes with their chainsaw to give me the fire-friendly lengths to split.

So, I've been doing little things inside - the sort of job that normally I don't find time for as there is usually something far more important to do.  Last winter there were lots of tasks left on the rebuilt extension, but now there's no excuse.  The first thing to do was to sort the wardrobe: I built this in 2011 as a stud wall, a foot in front of the fireplace in our bedroom, the whole way across the room.  This was done so that when we moved in we had somewhere to put our clothes which was a little less dusty!  Sadly, the recycled doors sat forlornly (getting in the way) awaiting repair, repainting and fitting from then until I managed to do the repairs and repainting last autumn (only a whole year...).  However, the fitting had to wait and was eventually done in a hurry on the Saturday before Christmas 2012 (that was 17 months...) as I had some time and realized that it would make Jane smile.  They are all done now and look really good - they even make the room seem bigger as there is nothing falling out of the wardrobe!

Also before Christmas I made a new coat rack for the hall, recycling some old coat hooks which I had kept from two years previously.  The previous coat rack is still in place but hardly used as (a) it is above the radiator and seems to absorb the heat and (b) it is so high that Jane cannot hang coats onto it!  Having moved the coats, the hall now seems larger as well.

Now I've moved on to finishing the tiling in the bathroom - there was an annoying bit which was where the tiles met the window frame; this needed some decent cutting and of course I had bought a good tile cutter ages ago but still never got round to this little job...  It's done now and is awaiting grouting - that reminds me, there's also a bit left for grouting in the extension utility.

Perhaps next I will see if it is possible to fit the bath panel properly - this has also been left since we moved in, resting almost in place, due to the impossibility (it seems) of getting it to go under the lip of the bath.  Then there's the repainting of the doors on the landing; these were also done just before we moved in, and it is amazing to see how much shrinkage there has been since then - on the door panels there is a whole centimetre of dark wood showing where I had painted white.  The dampness in the house must have been much worse than I had realized.

One other external and long awaited job that was done before it snowed was that the roofers came back to fix a slipped slate which had been outstanding since about last April.  This had not been done because it was directly under the chimney and thus a roofers ladder couldn't be used, but it was too far up the roof to allow it to be done with a ladder resting at gutter level.  Hence a cherry picker was required and, to save money, this had to wait until one was hired for another job.  Hence after such a long wait I was quite surprised when they turned up in early January.  As you might expect, it took longer to position the cherry picker than to actually do the job, which was a single lead tingle to hold the slate in place.  Since the cherry picker was resting on the lawn, they needed some spreaders to stop the feet digging in, so I found some rafter ends (7" x 2") from the construction of the extension and left them to it.  When I came back, they had finished and gone, taking my bits of rafter with them!  Oh well, I suppose they weren't valuable, but they have been useful for a good number of tasks in the last year.

Fat Birds and Drunk Slugs

We've been getting some surprising pleasure form watching the antics of the birds in our back garden.  I knew there were lots of bird resident locally, and was quite worried about depriving many of them of their nesting places when we cleared the garden.  Hence I made sure that the hedgerow around the walls of the garden was left as it was, with thick ivy and various other shrubs growing up/on/through it.  Last autumn we put up a bird feeder in which Jane puts those fat balls that you can buy; this hangs from the apple tree just outside the new kitchen window and so we have a good view of the goings-on. 

Firstly, there is a healthy flock of house sparrows here (some of who actually used to live in the wall of our house!), and they are quite adept at imitating blue tits and hanging on the feeder cage to peck the fat.  The apple tree has a high canopy and a single low horizontal branch which is bare for the first ten feet, and there are often three or four sparrows perched there waiting whilst others are feeding.  Then there are some Blue Tits and the odd Great Tit - they prefer not to mix with the sparrows who are quite noisy and possessive.  A surprise earlier in the year was the sight of three juvenile Long-Tailed Tits, and we were very happy recently to have further sightings of several of these relatively unusual birds.  There are a couple of Dunnock who only peck at the bits on the ground which have fallen from the feeder, joined occasionally by a Chaffinch.  Finally, there's a Robin who is more than possessive.  He is a little thug who terrorizes the other small birds to claim ownership of the worn patch immediately below the feeder, and occasionally (largely unsuccessfully) tries his own impersonation of  Blue Tit on the feeder.

The heavy mob obviously are ground feeders as well.  There's a number of Wood Pigeons (and the Robin knows his place with them), but there's also a pair of Collared Doves who dislike the Wood Pigeons!  It's a real soap opera out there sometimes.  Blackbirds are rarely seen - there was a melodious one who used to sing beautifully, up and down the street every morning and evening, but he fell silent in August and so I expect a cat got him. The last of the ground feeders is a mouse who I have seen just twice, when the area was quiet. We also have a Wren who lives in the hedge on the wall, but he is rarely seen and is cetainly not tempted by the fat balls.

The front garden wall is unfortunately just the right height for passers-by to sit on. I don't usually mind this, apart from those who sit there talking loudly, especially when we are trying to sleep, but since I did the secondary glazing this has not been such a problem.   I also object to those who sit there eating and drinking (again, usually at night) and then leave their rubbish in our garden. One of these the other day had clearly had too much to drink, as I went to pick up a can in the morning and found that it was still sealed. Shame I don't drink lager...  At the same time I picked up another open can which clearly had some liquid still inside, and found when I tipped it out that it contained about 20 dead slugs!  Obviously the advice to gardeners to use beer in a can to eradiate slugs does work! 

Reflections on the Last Two Years

Now that I have a bit more time for activities other than building work, I've been thinking about what has been acheived in the last two years and two months.  Specifically, I've been thinking about two aspects of the work, namely the things I've done which have really pleased me, and the things that I would rather had been done differently.

Under the latter heading come a few things which still bug me:

• The attitude of the Conservation Officer - this relationship seemed to have gone wrong near the start, but I still don't really know why, other than because (just possibly) the CO really IS an unhelpful person.
• The fact that Highways at the County Council told me that I could not widen the existing gateway to make a single driveway entrance for both houses as it was too close to a junction, but then (after I had made an entrance in the old wall) they allowed my new neighbour to make a new entrance even closer to the junction!
• A newly laid slate has slipped from the roof to the gutter, but the roofer has yet to come and fix it.
• The new kitchen sash window is four over four, not two over two as the rest of the windows.
• There is still no vent to the kitchen...
• Thames Water fitted an external meter in the pavement and this has been found to be a joint supply. Now we have to get an internal meter fitted, but that would have been so much easier if done before the new kitchen was fitted, as I intended.
• My new loft hatch is not quite square, because the joists were not parallel!
• The new extension is not exactly as intended - the roof is higher, the chimney lower and the plasterer gave me incorrect answers to two clear questions, with the result that the internal work I did is not perfect; one window cill has thicker render than he said, so it's almost level with the top of the lower window frame, and a plastered stud wall is thinner than the rendered blocks that it rests on.

Looking at the good side, there are lots of things which make me smile:

• The stone wall where I filled in the bottom of the old doorway
• The wall which I lime-plastered myself (the stone wall which is the join between the old house and new-build extension)
• The new 6' stone wall beside the front door, and the attached gates
• The new sash window which cost just £95 from a reclamation yard
• The front room floor where I replaced bits of joists and re-laid most of the boards plus some reclaimed ones
• The stud wardrobe frontage which I built for the master bedroom
• The wood-burning stove in the kitchen, in the alcove which I "found" by removing the old tiled fireplace
• The recently fitted secondary glazing (we are cosy, and it is quieter now)
• The limecrete/black limestone floor in the kitchen (laid by Chris, Shane and me)
• The black limestone floor in the new extension which I laid entirely by myself (on concrete...)
• The extension roof on which I laid over half the slates in just over a day on my own, much to Chris's surprise
• The casement window in the new extension which I salvaged from the old extension and did a major repair job
• The 1800+ Imperial bricks from the old extension which Jane and I salvaged and were re-used in the new extension (I only had to buy about 200 more)
• All the other little bits and pieces from the old building which I laboriously removed, kept and re-used
• Buying my own mixer, instead of hiring one
• Deciding that I would manage the entire process myself, instead of paying a builder to project manage it

Actually, the whole place makes me smile - it just feels so safe, solid and secure, just as a home should feel.

Secondary Glazing

I mentioned before how the Conservation Officer (erroneously in most people's view) sweepingly declared that "you can't have double glazing in a listed building".  That was in relation to a brand new sash window (far right below) which replaced a metal Crittal door and two windows on the side of the house (near right below), which seemed an inexplicable decision; I made sure that the design of the window will allow for double glazing if I so choose in the future, and the CO never realized!  I should point out that I agree that, in a building like this, one should not remove old sash windows and fit uPVC ones as they always look wrong - the thickness of the glazing bars is a real give away apart from the lack of wavy glass - but I did think that DG in a new window would be allowed. Anyway, with that history, I was never going to bother to mention the subject again to the CO, and so the house has remained draughty with a corresponding high gas bill last winter. As a result, I turned my thoughts to secondary glazing, and recently this came to the top of my list of "Things to do before winter". 

Secondary glazing is acceptable on period properties without conservation consent as it a reversible change (other than a few screw holes), and also it is not like double glazing, in that the space between the two panes is not sealed so it does not provide the same barrier to heat loss.  Basically it does reduce heat loss to an extent, but it also reduces draughts and noise.  The sash windows in this house are ideal for secondary glazing as the frame of the sash provides a good flat surface for the inner sheet.  You can get complicated systems which, for instance, add sliding glass in a frame, but I chose a simpler system which comprises a sheet of acrylic with a soft plastic edging strip, held against the sash window by little nylon clips and screws. I'm sure there are other suppliers, but I bought all my stuff from Tubeway Easyfix (http://www.tubeway.co.uk/).  They were kind enough to send me, free of charge, a plastic mitre block for cutting the plastic edging, which got omitted from my order.  Since this item retails at £7.05 + VAT, I'm glad I didn't pay for it; you would think they would always throw such a little bit of plastic in for nothing.

There are relatively few issues with this system, although the price of the acrylic sheet surprised me; I used 2mm thick sheet, although you can use 3mm or 4mm (even more expensive!).  One issue seems to be the size of the sheets; most of my windows are 90cm wide, and so need acrylic sheet which is about 95cm wide; of course, one of the standard widths is 92cm so I had to go to the next size up, with consequent additional waste and cost.  One potential difficulty is cutting the acrylic; I was told that could probably score the acrylic and break it like glass, but even with 2mm thick, this just did not work reliably.  Hence it had to be cut and I quickly proved that you cannot use a hand saw as this causes cracks along with a very rough edge. However my jigsaw with a fine blade proved to be the business so long as you don't move it too quickly, but even then you need to support the edge at the point of cutting or you get a jagged edge with cracks.  Straight edges help with positioning the clips, so I always made sure I had an edge cut by the supplier along the bottom when I fitted the first clips.

I've now done five windows, including the large one in the main bedroom.  This one was so large that I was unable to buy a sheet of acrylic big enough, so I have made a wooden horizontal support which runs across in line with the join in the sashes, so that it isn't seen from outside.

This support was made from four bits of stripwood, and there is a groove top and bottom to hold the edges of the acrylic; the strength is primarily from an expensive piece of hardwood (30mm x 10mm) which forms the visible side in the room. Photos of the system are quite difficult to do, as all they show are the windows and you can hardly see the edge of the acrylic, which is the whole point really.  However, here's a detail picture so you can see the edging and the clips:

The draughts have largely gone and the difference in room temperature is quite noticeable; it really does make a difference and there is now less need to keep all internal doors closed.  I've still got to do one in the hall, one in the extension and a pair in the bathroom (left); the bathroom ones fell to the end of the list due to the refurbishment work needed on the window frame and the fact that I will have to re-fit the venetian blind on another bit of stripwood to hold it away from the acrylic. The main renovation of all these windows will get done next summer (if we have one) and the main aim will be to keep the old glass wherever possible.

Having eliminated a lot of draughts, I will have to make sure that the house is still well ventilated - there has been no dampness or condensation anywhere in the last year since it dried out, apart from what we caused with cooking and showers.