I built my two storey extension for 20% of builder's quotes

This site shows how - step by step from design to completion

Felting and Battening the roof

Eventually I was in a position to lay felt and batten out the roofs. This would be a big step to being properly waterproof. I had been using tarpaulins over the trusses, but they can only do so good a job, and when the wind blows the damn things rustle like mad - the rain then finds its own lovely little route to somewhere you don't want it.

Unfotunately, having found a sunny day I was deparate to crack on, so my photography duties were a little neglected. I will do my best to describe what I did. If something is confusing or you want extra info just send me an email.

tarpaulinI kept waiting for what I hoped would be a dry and calm day so that I could start to lay the felt. I then removed the first tarpaulin and set to work.

I would be laying plain 'rosemary style' roof tiles to match the main roof. I didn't have the tiles yet, and was searching ebay for some reclaimed tiles. 

Rosemary plain tiles have a double headlap, meaning that each tile overlaps the two tiles beneath it. I soon realised this meant a lot of tiles and a lot of battens.



batteningThough I would try to find some reclaimed tiles to best match my main roof, I checked some tile manufacturer websites to get the technical spec for plain tiles. I would need 25 x 38 battens at a maximum gauge to 100mm.

I worked out the position of my eaves batten by placing a couple of tiles and ensuring the tiles would overhang about 50mm (which was about the centre of the gutter). This was the position of the lowest full tile, there would be one batten below this to take the shorter eaves tile.



battensI then measured the distance from the batten to the apex so I could work out an accurate gauge. Though 100mm was the maximum, I didn't want to just start battening at this gauge to find I had to change gauge at the top to get them to fit. I worked out I would need 30 battens per side (120 in all), and if I set a gauge of 98mm they would run nicely and finish at the apex. (I hope that makes sense)

I bought 'breathable' roof felt (I think most are these days) The manufacturer says these felts offer sufficient roof ventilation on their own provided they are installed in accordance with their instructions. However, as you will have seen from the previous article, I installed eaves vents too.

The day proved not to be as windless as I had hoped, so unfurling roof felt and trying to get it laid on my own proved tricky ( I found a little swearing helped).

harnessI cut three pieces of timber to act as spacers so I knew each batten would be spaced correctly from the previous one, and worked my way up the roof. The felt has handy lines marked on it so I could easily judge the 150mm overlap between sheets. It was a slow job working alone, but I got there.

Because my scaffolding set up is dodgy, to say the least, and I am actually something of a clumsy sod, I employed my old paragliding harness whenever I ventured onto the roofs. Not my best look, but as I spend most of my time covered in muck, sweat and mortar, my best look isn't that great either.

120 battens and around 1200 nails later I had all four sides felted and well battened down against the wind. I found that working on the roof at an angle all the time, and having to crouch a lot made my legs ache, but I didn't care - the rain would be much easier to keep out now.