johnr's Shed roof repair

Shed roof repair

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My garden shed must be about 50 years old - the sides are made from cedar wood, which seems to last forever. But, every 8 years or so, I've had to replace the roof felt; it looks lovely for a while, but then repeated baking and freezing start to take their toll. First the top "mineral" layer loosens and gradually blows away, then the base gets thin and brittle, and eventually large pieces are torn off by the winter (and, nowadays, summer) gales. I've tried various grades of felt, but they've all ended up in tatters and letting in water, especially along the tacking lines where the timber is a pepper-pot of holes. By 2019, an area of about a square metre had rotted beyond the point of no return, and there were permanent puddles on the concrete floor - time for drastic action!

[Rotten roof timbers] [Replaced portion of roof] [Roof covered with flashing tape]

First, I removed the rotted timbers, and fitted new supporting joists and rebated shiplap boards. Thus far, an unexceptional repair story; the reason for its inclusion here is my novel choice of covering material. I'd successfully used self-adhesive flashing tape for a number of running repairs to the old felt, and a few years ago I'd tried applying it, in place of felt, to cover a timber coal-bunker lid, with great success - still going strong with no visible deterioration. So I opted to do a similar job here, on a somewhat larger scale.

Self-adhesive flashing tape is available in rolls of 10m x 250mm, i.e. 2.5 square metres area. Four such rolls covered my roof perfectly, starting along the rear (lowest) edge, and with a 60mm overlap of each successive strip. Granted, the stuff isn't cheap - but for me the cost was more than justified by the speed and ease of application compared to tacked mineral felt. It's also much easier to carry home from the DIY store! At the time of writing the job is a year old, and for the first time in recent memory the shed interior is permanently bone-dry and sweet-smelling!