An Eccentric Anomaly: Ed Davies's Blog

I've made quite a few mistakes building this house (not to mention finding a lot of things I'd do differently in hindsight) but I think the worst has been thinking I'll get the roof covered soon then not doing so.

But first some eye candy. When I arrived on site on quite a few days in the early autumn there were one or two buzzards sitting on the roof.

A rather intense rainbow late in October.

Just down the road after leaving the site in early November. View down the coast to the SE. North edge of the Cairngorms south of the north Moray coast visible across the sea.

As previously mentioned I have in mind to cover the roof with corrugated (as opposed to trapezoidal) steel sheets. Early in October I approached a company I'd talked to previously about putting this on but, with the Covid working practices and furloughs, etc, they were booked up well in advance and didn't want to even quote.

Over the rest of the month I thought about the practicality of doing corrugated steel sheets myself. Keeping them small it wouldn't be too bad, I thought, even though it'd use extra material in the overlaps.

The battens up the roof are on 850mm centres. There are 10, so 9 gaps to cover. Accordingly, I had in mind to use 2850mm sheets needing 3 sheets for each “column”.

On the 21st I popped into a roofing company in Inverness to try to get a quote. They were too busy to talk to me (I wanted to ask about colour and coating type options, relative cost of 0.5 and 0.7mm thick sheets and delivery) despite the likelihood of me spending something like £3000 with them. I left my details and got an off-hand quote the next week by email but was a bit underwhelmed.

Accordingly, I visited a local builder's and agricultural merchants (which, though I've got bits from them from time to time, I keep forgetting about) who were much more helpful and a bit cheaper. Accordingly I ordered enough sheets from them to do a little under half of the north roof to see how I'd get on.

They didn't have many of the screws for these in stock so I had another trip to Inverness to get some from the previous roofing company. In the evening while reading online about fitting them I realised I'd need short stitching screws for where the sheets join unsupported so ordered them off the bay, noticing at the same time I could have got the main screws for £25 less from the same source. Oh well, I'll know for the next lot.

In November I did the boarding at the top of the east gable. This took quite a while as I found it quite difficult to get the measurements for the slopes right and consistent with each attempt taking, essentially, a whole of the very short days, what with putting the scaffold tower up and taking it down.

At least I could make use of some wet and windy days to cut and paint the boards. I painted quite a lot of extra boards with the idea that they would be used at the top of the west gable and round the bottom of the house.

As can be seen the picture above I also put some fibreglass mesh up to cover the gaps at the tops of the boards. Here's a view from earlier to help visualise this.

Mesh from a bit closer.

Then added red firestop and black DPC, just remembering to photograph the firestop before going all the way down with DPC.

The agricultural place gets their roofing sheets delivered every other Thursday. I'd popped round a few times to ask “this Thursday?”, “nope, we'll phone you”. By well into December I was getting a bit bored with this and had more-or-less determined to cancel the order and buy the roofing online but was feeling a bit delicate mentally so kept putting off doing that.

On the 15th I finally got round to cancelling. When I got home I went online to find that the place I had in mind didn't have black sheets (needed for my planning permission) in stock and weren't accepting new orders for them for the time being. I did think about buying another colour and painting them but was quickly convinced that was not a good plan.

I had the idea of covering the roof above the 35x50 battens with sarking boards (treated 22x150 boards as are already on the roof and under the floor) going up and down the roof. That would give temporary covering which would keep off most of the water and also give a base for putting on one of the lighter steel roofing solutions around.

I visited by local timber merchants on Friday the 18th, as everything was shutting down for Christmas and possibly more lockdown, to see if they could deliver some on Tuesday of the following week. They knew the wagon was full for Monday but didn't know off hand for Tuesday, I should phone back about it on Monday.

That was all getting a bit fraught so I decided to not get panicked into anything, instead putting tarpaulins up to protect the roof for the time being. Proof of concept with the one reasonably intact tarpaulin I had to hand at the east end of the north roof:

That seemed OK so on Monday the 21st I went to Inverness and got a big pile of tarpaulins. It was dry, calm and un-icy enough on the 22nd, 23rd and 28th to put up the first three, one per day, on the south roof.

I'd got 9 smaller tarps and two larger ones (what they had on the shelves). One of the large ones would have been good to fill the width to the west end of the south roof and covered further down at the end most exposed to the prevailing wind. Unfortunately I got its orientation wrong, landscape instead of portrait, so finished up with wasted sheet hanging over the end. Here I'm in the process of folding the extra back over and fixing it in place.

Top bit of south roof done so at least the tops of the windows, where the most significant leaks were, are protected.

Entrance track on the worst day of snow on which I worked. There were one or two days with a bit more but didn't go out. AIUI, some places further south had quite a bit more.

Getting the sheets up, I stapled the batten across the top then rolled/scrunch the tarps up and used some clamps to hold them together. So long as it was reasonably calm it was easy to carry this combination up, clamp it to the topmost batten, put in a few screws as far as I could reach each side of the middle, unfurl it and climb down under it.

Surprisingly, the awkward bit was getting the scaffold tower bits down. They fit quite neatly between the top batten and the ground.

That's excellent until you want to take it apart and need another 200mm or so of room to push the tower parts apart. On the south roof that wasn't much of a problem as I could move the tower out a bit, use a clamp as a spreader to support it then pull the bottom bit out. On the north side there's quite a steep step in the ground to stop that. For this one I had to take the bottom bar off the tower and wriggle the legs into the stones to make enough room. For the remaining tarps on the south roof I've removed the top 1m section of the tower before unfurling the tarp.

I attached ropes to the bottom corners of the tarps and tied them off at the bottom before the tarps up so at not to have the wind pick them up and blow them over the ridge, or anything like that. Here, using the rope to hold the tarp as flat as possible to avoid too much billowing once it's all screwed in place.

I've now done all but the last of the top tarps on the north side. I'll put another one over that first “proof-of-concept” tarp as I made a mistake in the way I battened it in the middle and it's now got a large hole in it. Then I'll put my last remaining smaller tarp in landscape orientation below some of the currently fitted ones. If that's OK I'll go and get some more to cover the rest of the bottom part of the roof.