Despite months of preparing and chasing to get a Green Deal since March 2013, our actual Green Deal installation happened to coincide with my main PhD research in winter 2013/14. This meant I did not manage to blog about the process as we went along; but I did end up taking many pictures - often once the installer had left for the day and I returned from my fieldwork. It also meant that I missed out on being there for several crucial stages. For example it was my husband who was around when Instagroup came to inspect the works on two occasions; when the window cills were measured and installed and reveals insulated (only very few); when the insulation was mechanically fixed and gaps filled; the eaves capping was installed and I was also not present when the services were finally insulated and boxed in nor when the rendering and painting took place.
Being unable to witness and influence the Green Deal installation process is definitely frustrating as an architect (and when knowing a thing or two about thermal bridging), though it probably prevented me from becoming the 'client from hell' by interfering. As such I do think that our experience and installation is probably fairly typical of a Green Deal installation and I will write another blog about some issues with standard detailing and trying to find solutions with the installer (who were as flexible as they could be within the constraints of Instagroup's EWI system and Green Deal approval).
Actually, I bet you can identify some of these issues and (potential) problems from some of the photographs below, without my commentary? Do leave comments!
Roof insulation and waterproofing (not Green Deal)
The existing roof basically was just some asphalt on timber boards over timber joists. You can see here where the previous owner had the chimney removed and had run a new piece of asphalt across this gap! On the right is the new roof on top of the old: 18 mm OSB + vapour barrier + 100mm ECOTHERM insulation board (k=0.025 W/mK) + underlay + waterproofing. The new timber edge is to enable the 100 mm insulation and the roof also overhangs by ~ 150 mm over the wall to meet the 100 mm EWI at later stages, avoiding typical EWI Green Deal capping systems for most of the roof - see pictures. NB: We will still need to insulate in between the joists from the ceiling at some point,...
EWI installation process
Our Green Deal process has finished exactly a year later - and we have just submitted paperwork for our cashback.
Firstly, scaffold was installed in late November to enable flat roof insulation and new waterproofing, a process which took < 1 week. In early December, the scaffold was adjusted further away from the walls to allow for future EWI installation and things initially took off quickly. However, soon delays occurred due to darkness setting in sooner at that time of year and on many occasions the guys on site had to wait until temperatures were > 5ºC and rising to glue the insulation to the walls. As a result the works did not finish before Christmas and New Year 2013, and around this period much of the UK witnessed extreme weather leading to further delays on site: rendering and painting can only happen when there are several days of dry weather so there were several weeks where nothing could happen. A few Green Deal installers told me that they had been under pressure to render several houses to finish on time (before the cash-back ran out or ECO would be scrapped) and overnight rain washed the render away and it had to be all scraped off and redone at another time - so things could have been worse I guess!
Our window cills also took almost 2 months to arrive!
EWI installation stages
NB: I will be taking some InfraRed images too and will post them here at some stage,...
One evening in late December, I came home from fieldwork and before going to bed I noticed that our bathroom floor had a ‘water pattern to it’, but was dry to the touch (see image below).
I found a small (clean water) leak behind the toilet, seeping slowly into the floor grouting, being absorbed by the permeable surfaces under the glazed tile surface. In the kitchen you could hear water dropping every second and a faint mark on the plasterboard had appeared. I knew we had to somehow locate the leak quickly, as wherever it came from, the water was leaking out into the timber ceiling void below. Our kitchen has recessed lights so I switched the electrical lighting circuit off as a pre-caution.
I then armed myself with a torch and climbed up on the scaffolding; to see if the installation of the Green Deal external wall insulation pierced through any services. But I realised that this seemed unlikely: the GD team had shown me the thermally broken plastic fixings (2 per insulation ‘ slab’) – and while they were long enough to fix back through to the brick wall behind, they are not so long to go through the brick and then puncture services behind.
We realised that we could temporarily stop the leak by turning the mains water supply off and flushing the toilet to empty the cistern. At this point we could not access the cistern (we bought the house with the cistern built in and no means of getting to it) so decided to go to bed at this stage, but only after leaving urgent messages with our Green Deal installer. They arrived first thing in the morning and spent a full morning dismantling the WC and fixing the leak. Soon it became clear what had caused the leak:
Had the WC been properly installed, there would never have been a leak. We offered our Green Deal installer to pay for their time to remediate the leak; clearly this was not their fault or responsibility, but they kindly declined.
So kudos to our GD installer, but this story highlights the wider unforeseen problems and uncertainties that may happen when working in existing buildings and GD installers having to deal with and navigate around dodgy building work; not knowing what might happen next.
(and no, we did not keep the T-shirt!)
This is Sofie's blog; or rather a collection of musings & articles sometimes also published elsewhere. More about Sofie here.