English Roofer Brittany

Not long ago, I built a new roof from scratch. This was my first roof and luckily it was for a play area, so if it leaked, nothing of value would be ruined. Most of the materials used were new except for the tiles which were reclaimed.

(Central Brittany Slate Roofing project - Play-barn) 

Having the opportunity of building this with both the clients understanding that this was my very first and having the trust in me to complete it was an honour. 

It was a project I always wanted to take on, especially using a traditional roofing material such as slate. I knew the principles of construction and have the skills with putting something of this size together, but nothing is as good as physically building.

Being an interior builder, I have the tools for cutting, shaping and nailing timber together. The only specialist items I had to use was a slate tile cutter and a proper roofing hammer.

(Slate Roofing Hammer & Cutter)

Building the timber frame isn't that dissimilar to building timber stud-work, there are rules to follow with regards to sizes of timber used as-well as the spacing between them.

Tiling is similar tiling a wall or floor, though using Tile hooks (crochets ardoise in French) for fixing not tile adhesive. One thing which isn't similar is the lapping of the tiles, his is something which is quick to learn though.

(Types of slate tile hooks)

Roofs in Brittany background basics

In Central Brittany, it's common to have black slate roofs built on stone walls. Properties are 40 to 50m2 per floor level and a roof of is usually at a 42 degree pitch and a surface area of 50 to 60m2. (And no they don’t follow the golden ratio – 1:1.62!)

The construction is simple. The ridge beam and purlins are generally set in the gable ends, the rafters are then nailed 90 degrees to the ridge and purlins (set 400mm apart, on the rafter centre). Then you have barge board 90 degrees to rafters, with a waterproof membrane (sarking felt) running 90degrees from the boards and tiles sit on top.

(Half Gable Roof in Central Brittany)

(Barge-boards nailed)

Tips and Tricks

Type of ladders - As you can see from the pictures, this roof is a half gable, IE the Ridge beam is against the gable end of the existing building. As such this makes a modern roofing ladder useless as you have nothing to catch onto.

I noticed that the local roofers used wooden Ladders and I quickly pick up the reason why. Using the crochets, you could attach the ladder.

NB There are two types of Crochets as well as many sizes - Crochet Point, you hammer the point into the barge board. Crochet Agrafe hooks over battons instead.

Tile sizes, and mapping out - There is not much to say about tile sizes, usually the size and type of material used depends of the available budget. I was using reclaimed slate tiles 200mm x 300mm, As such, I used 100mm long crochets as this allowed for a 3 overlaps of tiles. 

With regards to mapping out, I did very little in the way of chalk-lining. As the tiles are 300mm and the Crochets are 100mm, you'll generally stay straight and true, though do check once in a while.

 I did ensure that the horizontal and vertical of the timber frame did have a 90 degrees angle on the edges.  

Using the sarking as a guide - When buying sarking, you will notice that it is generally 1100mm in width, you are to overlap the ends 100mm (which the sarking has a printed line as a guide). If you set the guide line 90 degrees from the ridge/top plate or the verges then it becomes a great guide for the tiles.

(Sarking Felt overlay)

How to start off - You start from the bottom and work your way up. With a 300mm length tile I set a 100mm overhang at the bottom. To do this I measure 100mm up from bottom of the barge-board at either end and chalk-lined. Then 101mm parallel above the first line, I chalked again. (The 1mm allow for the 2.7mm thickness of the Crochet.) Repeat this 2 or 3 times and that should be enough.

The first run of tiles I turn 90 degrees and nail. (So the top of the tile lines up with the chalk-line and you have 100mm overhang.)
The second run sit direct on the first set of tiles, but now the correct way round. Both first and second set of tiles should be flush at the bottom and the top of the second run should line up with the second chalkline.

  

How to do your runs - There are two ways of doing your runs, either build up in pyramids of in straight line. I worked out if you laying tiles on your own, then doing straight line of 4 tiles per line, allow you to do 90/100 tiles an hour. If there are two of you, then the pyramid is faster.

(English Builder in Central Brittany - My first Roof)