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

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

Eaves Ventilation strip

The temporary tarpaulins were getting really annoying. They flap and rustle in the wind, and though they do a pretty good job of keeping the rain out, they are not perfect. Unfortunately, I still had quite a lot to do before I could get the felt laid.

Working solo on a roof is a slow job, not least because I keep climbing all the way to the top, looking for my tape measure then spotting it on the ground down at the bottom - still, it keeps me fit!

I will be fitting breathable membrane to the roof. I spoke to the manufactures and they assured me that provided certain conditions are met there is no need for additional venting to the roof as the breathable nature of the felt will prevent condensation build up. Basically, the felt allows water vapour through, but not water (a bit like gortex).

However, I decided to fit eaves vents, similar to those on the main house, to be on the safe side.

eaves_ventsThe vents comprise of sections of grill that allow the air in, trays that fix to the rafters and ensure that the insulation does not block the flow of air, and an eaves protector (in following picture). The eaves protector covers the vents and also acts as a support for the felt, preventing it from sagging between the rafters and allowing any water that has got past the tiles and onto the felt to drip into the cavity rather than be channelled into the gutter.



eaves_protectorFixing the vents was a little awkward for me because of the corbelling and lack of soffit board. I drilled holes into the brick work and fixed the nails you can see into the holes with resin left over from when I fixed the studded bar into the wall for the joists.

The eaves protector can be  seen overlapping the vent and in position to feed into the gutter. It also runs up over the trays in the previous picture.

Over the next few pages I will deal with felting, battening, box gutters and valleys. In reality these jobs were not carried out sequentially as the pages suggest. It was necessary at times to do a little valley preparation then a little gutter, then back to the valleys, each job often relying on the other.