Withington Co-operative Eco-house - insulation

Spacetherm - 1st day

Robert — Wed, 25 Sep 2013 18:44:49 +0000

Here's where the ground floor front room is up to, after the first actual day of Spacetherming:

They've approached in a fairly sensible manner: yesterday they set up a cutting area, and did a couple of tests with small pieces, figuring out the fixing and jointing methods. Turns out that it can be drilled OK (we were advised that drill bits would get snarled up), but getting continuity on the outside angles is really tricky; because there's a built-in VCL behind the plasterboard, any discontinuity of this will create more work afterwards, to get the vapour seal.

Another issue that's cropped up is that due to irregularities in the brickwork and the walls and joists not being quite at right angles, they can't slot the Spacetherm down between the frontmost joist and the wall; some PIR will have to be used instead here, which again is a risk area from a VCL-continuity perxpective.

In other news:

The builders took advantage of the fine weather yesterday to do some snagging on the roof (though still a little more to do there), put the fascia boards on the front
Today they also did one of the knock-outs for the rear patio doors
The plumbing is progressing, but very slowly. I had to resort to ripping out some of the pipework that the "plastic plumber" had fitted, because it was unsatisfactory; needless to say that this didn't go down well! I've resorted to installing the rainwater harvesting system myself now - managing someone else into doing quite literally would take longer than doing the job myself - whilst leaving him to do more "normal" plumbing like radiators
I also had a very positive conversation with a Viesmann installer regarding a replacement for the now effectively abandoned Baxi Ecogen; awaiting costings etc from him in the next couple of days

Spacetherm internal wall insulation (and a general update)

Robert — Fri, 20 Sep 2013 18:32:11 +0000

A while since the last entry... we've now taken delivery of £4,500-worth of Spacetherm, for internally insulating the front wall (see article for a more detailed description). As the delivery was on an 18-tonne truck, we had to decant it into my 3.5-tonne van in order to get as close as possible to the house. The contractors are using their joiner to fit the Spacetherm: a slightly curious choice, but makes sense given that there's some difficult angles around the bay windows, and cutting the stuff neatly will be half the battle.

The walls have been prepared now, and the actual fixing is due to get underway next week.

The plumbing is ongoing, with domestic hot and cold water and most of the waste pipes in now, we're moving on to the rainwater system and radiator circuits next week. Although the on-site work is progressing slowly, the bigger difficulty is that I've had to pretty much abandon the original idea of using a Baxi Ecogen MicroCHP unit in conjunction with a thermal store/buffer vessel. Although it's great in theory, the reality is that Baxi don't have a wide enough installer network for a one-off installation like ours to be achieved cost-effectively. So I am, reluctantly, looking at a condensing boiler system instead - will write more on this next week.

The plaster is pretty much dried out; the builders have fitted the new lintel over the front door, and the new kitchen door was delivered today; will be fitted next week.

United Utilities have promised us that they will be gone from outside the house by 2 October. Fingers crossed!

About road blocks, and burning gas

Robert — Mon, 19 Aug 2013 22:12:49 +0000

It's rather ironic given today's events in Balcombe that, as far as the Withington Co-operative Eco-house is concerned, roadblocks are bad news, and burning gas is good (well, less bad, at least).

Unitied Utilities have enlarged their fenced off area and moved about half their equipment into the new part; it remains to be seen whether they'll hit their latest self-imposed deadline of clearing the part in front of the house by the end of this week. I intend to get a clearer picture of this by the end of tomorrow. Back To Earth, the EWI supplier, are concerned about being able to gain access at the pre-agreed time, so to be on the safe side I have pushed back the EWI to September. As things stand though, the window delivery and fitting is still timetabled in for next week (and given the difficulties I've had with the window company, I really don't want to change this).

I've been to-ing and fro-ing with my contact at Baxi, regarding our proposed Ecogen installation. It seems that it is do-able, so I now need to get the company that will be doing the Ecogen install to agree to the specification from myself and Baxi - but my contact there is on holiday until next week.

It might seem paradoxical that burning gas is the most appropriate choice for an eco-house. I'll be writing a full article on this once the details are finalised, but in the meantime suffice to say that we did look into the issue, and gas-fired plant is very much the lesser of evils for a house of this type and location. What's actually more important than the choice of fuel is to minimise the amount of fuel burnt - hence the superinsulation. And according to our calculations, the size of boiler we need to heat our 6-person eco-house is smaller than what is typically installed into a one bed flat.

Speaking of which, the roof insulation is almost complete now, with Andrew on-site today and returning tomorrow to work with the builders to address a few detailing issues with the air-tightness tapes and sealing.

Insulation again

Robert — Sat, 10 Aug 2013 22:21:07 +0000

Today I went to the house because I'd agreed to meet the electrician on-site, to go through a few issues regarding cable routes etc.

Whilst I was there, I noticed that the builders had completed the insulation in the front attic room, ready for beginning the taping on Monday morning (the back rooms still need another layer). However, although they had mainly done a good job, where they had stuffed the void behind the purlin with quilt insulation, it had pushed up the 25mm PIR boards, compromising the air gap for ventilating the roof:

Something to take up with them on Monday, no doubt. They've also taken delivery of a pallet-load of 9mm plasterboard, which seems a bit premature to me considering they haven't even started the taping yet, and still have the bottom layer of PIR to put on at the rear.

Meanwhile, the costs are in for the VIP - significantly cheaper than Spacetherm. I've been reading various things about VIP and the main concern (apart from vulnerability to puncture both during installation and in service - both of which I think we can mitigate on this project) is degradation in performance over time. Need to clarify the situation with the suppliers on this issue.

More insulating

Robert — Thu, 08 Aug 2013 23:02:09 +0000

Today has been all about insulation. The builders have been making good progress with the PIR in the attic - more on that below. I've just ordered another £180 worth of air-tightness tapes and sealants from Green Building Store, which should arrive tomorrow, ready to start taping on Monday. And I've also been costing out the VIPs (that's vacuum insulated panels) for the internal walls in the ground and first floor rooms, at the front. VIP is the only thing that can get us the required U-value in minimum thickness, but not without difficulties, in terms of needing battening (recommended in phenolic foam, but still, relatively, a cold bridge) and danger of puncture (ruining performance) both during installation and by occupants of the building. Hopefully the costings should come through by the end of tomorrow.

As I mentioned, the PIR installation has been proceeding: they've got most of the first layer (25mm between rafters) in, started the second (75mm) layer at the rear, and completed this and on to the third (75mm) layer at the front. The builders came up with an unusual-looking, though effective method of holding the third layer up to the second, whilst the adhesive cured:

Overall, both Andrew and I are pleased with the standard of the insulation work. However, there have been a few issues, the worst of which is this:

Needless to say, I need to have a word with the electrician when he comes back on-site on Saturday!

The roof insulation begins

Robert — Mon, 05 Aug 2013 16:51:52 +0000

Today was an important moment for the Withington Co-operative Eco-house - the first time in the 100-odd year history of the house that a piece of insulation was fitted! And here's Eddie the builder putting it in (sorry about the thing in the foreground):

We're insulating both between and below the rafters with PIR insulation (not the most eco-friendly of materials, but weight limitations preclude using anything else). This is the first layer of insulation, which goes between the rafters:

After this, there will be 2 * 75mm layers below the rafters - total thickness 175mm.

Great care is being taken to ensure a through-flow of air through the roof structure, behind the insulation. For this reason, in addition to using a breathable membrane, we've fitted vents at eaves and ridge levels, and only used 25mm PIR between the rafters:

Getting ready to begin the roof insulation

Robert — Fri, 02 Aug 2013 22:38:14 +0000

We've engaged Andrew Gill, a CAT AEES graduate to assist with overseeing the fitting of insulation and air-tightness tapes, as this is beyond my expertise (I'm mainly focused on building services), and Andrew has first-hand experience of superinsulating a house in Manchester (see https://sites.google.com/site/lowerenergyterracedhouse/ for Andrew's very well-documented project).

The builders are almost at the point of being ready to start insulating the roof, so Andrew was on-site today going through things with them, and advising me of the (very expensive!) tapes and sealants that will be required - which I am to purchase directly.

Withington Co-operative Eco-house - insulation

Spacetherm - 1st day

Tags:

Spacetherm internal wall insulation (and a general update)

Tags:

About road blocks, and burning gas

Tags:

Insulation again

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More insulating

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The roof insulation begins

Tags:

Getting ready to begin the roof insulation

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