2022 So Far

An Eccentric Anomaly: Ed Davies's Blog

The weather up this end of the island this winter has mostly not been too bad. It's not been particularly cold or wet with only a few short groups of days with a cm or so of snow lying and the unusually strong wind storms have all passed us by to the south. It has, however, been persistently a bit windy so I've only really got going in the last week or so which has had some lovely weather (which has, sadly, come to an end for now).

As previously noted I only got one roof sheet up in January (a top-row one above the main-bedroom window). I also painted over the fork-lift scratches on the bottom of the bottom sheet from the last batch delivered and the next batch was delivered.

February managed to be even less productive. In the first half of the month I made a couple of visits to the site to tidy up scrap sheets which had been blown around by the wind a bit. Towards the end of the month I moved the gutter above the study window up to make room for the Velux flashing above that window.

If I'd understood Velux windows a bit better I'd have mounted the windows a bit further out from the roof surface (maybe 22mm) to allow that flashing to go over the top of the gutter but never mind.

On March 6th I took down the remains of the tarp over the study window, re-battened under that window and put up the first small sheet there.

There's a bit of a conundrum with these sheets and the flashings round the Velux windows:

The way round this I'm using is to have an off-cut of roof sheet about 150mm tall to use to mark out where the ridge positions from the sheets to the right fall then use that to position the sheets under the window. It seems to have worked in this case.

The next day I put up the second sheet under that window.

On the 14th I put up the one to the east (right) of the window and drilled the one to go above it.

There was quite a pretty sunset that night, presumably as a result of the Saharan sand which had been blowing up across Europe. Nicer than the effects it was having further south.

On the 16th I put up the sheet to go above and to the east of the study window …

… coming up with this mechanism to vertically position it in small increments:

and also the top sheet above and to its right:

The sunset theme continued. Here's the view looking east late in the afternoon with the shadow of my house and container across my neighbour's field:

On the 21st there was finally the start of a run of nice weather. I put up the easterly of the two sheets above the study window and the top sheet above and to its right:

On the 22nd I put up the westerly of the two sheets above the study window.

On the 23rd I put up the top-row sheet above the study window using a more experimental technique. I put my ramp over the top of the window held off it by some timber bearers lying on the top gutter of the window:

That worked well until the sheet tipped down at the top just before it got on to the upper ramp:

I worked around that by pushing a piece of batten across to lever it up a bit, after trying to just hold the bottom of the sheet down with a bit batten from below.

Up and screwed in place:

Having had a bit of a sedentary winter I was pretty tired after these days and the 24th was grey and chilly with a enough breeze to be unpleasant so when I got to site I decided to just go home again.

I wasn't feeling much better on the 25th and the weather hadn't really improved so I just stayed at home and got some paperwork out of the way.

On the 26th I was feeling a bit more energetic but still not great so I decided on a short day, putting up the bottom-row sheet to the west of the study window.

On the 27th I re-did the battening under the four remaining windows:

It's probably worth explaining what's going on here. The main battens across this roof are 35x50 mm on, nominally, 850 mm centres. This is because the membrane came in 1 metre width sheets and is overlapped by 150 mm so spacing the battens like this allows them to pin the sheets top and bottom.

All this goes on top of the 12 mm battens under the membrane which go up and down the roof.

The solar thermal panels are going across the roof below the windows. The mountings for those want three screws/bolts each side on 600 mm centres (that is at 0, 600 and 1200 mm above the bottom fixing). Commoning up the bottom batten for both the roofing and the bottom solar thermal fixing means having battens at 600 mm, 850 mm, 1200 mm, 1700 mm, 2550 mm and so on up the roof.

The complication, though, is that the sheets below the Velux windows want to go under the skirt flashings so need to be quite noticeably lower than the others. To get this, under the windows, I've replaced the 35x50 battens by 22x50 battens (actually 22x150 sarking boards ripped in three; they were painted brown with fence paint for another use before I decided to use them like this).

Rather than just put the 22x50 battens across the gaps cut in the 35x50 battens I thought it would be better to overlap them a bit hence the 22x50s sit on top (higher up the roof) than the 35x50s and so are on 900 mm centres relative to the bottom battens.

The photo above is a bit distracting in that it shows a bit of 22x50 batten on the bottom 35x50 batten (under the kitchen window). That's just a spare bit which happened to be resting there when I took the photograph.

With the gaps in the battens under the windows the solar thermal panels will need to be mounted on rails which are screwed in where there is batten available. I'm thinking Unistrut or similar.

Yesterday, the 28th, I went to site with the hope of doing the two sheets under the living room window and the one up its east side.

As noted above, the main roof battens are on nominal 850 mm centres and the thinner battens under the windows are 50 mm above those. Actually, measurement in this case showed the thinner batten was 897 mm (not quite 900 mm) on centres from the bottom batten. I added that to the 140 mm the bottom screws are above the bottom edge of the sheet to get 937 mm for the distance from the bottom edge of the sheet and the screw holes, losing a carry somewhere. Consequently, the pilot holes I drilled were 100 mm too low.

Hmm, what to do? I certainly didn't want to scrap this sheet for this and obviously couldn't leave the extra holes exposed as they'd rust quickly. I could've just put short stitching screws in but they don't seem to hold very well in a single sheet; they need two sheets to pull together to get proper tension. So, might as well have the extra strength of an additional row of full screws and batten. With extra batten added below the main batten, so 100 mm lower:

Both sheets below the window added. Click for full size to see the row of extra little screws on the right side.

Quite large parts of the left and right sides of these sheets will be overlapped by the sheets up the sides of the window. This is a bit wasteful of steel but does give a good seal as these sheets change level. It also means they aren't screwed down yet, that'll happen when the side sheets are added, hence the batten tied across temporarily to prevent the sides being picked up and twisted by the wind before I can get round to adding the side sheets.

It might be a while before I do add those side sheets. The weather today was OK but not great and it looks much worse for the foreseeable with wind and rain and, depending on which forecast you believe, snow overnight. It doesn't seem uncommon at this time of year; my neighbour shrugged and called it “lambing snow” when I commented that some of his new-born lambs probably wished they were still inside their mums in similar weather the other year.