After a month away from thatching helping Daisy with her loft conversion, I am reluctantly back in charge again. It was nice to not be the boss for a while and to see Daisy finish a project that she’s been holding in her head for several years. So now her youngest has a bit more space to grow into; some new style insulation that made the roof look for a while like it was destined for the next space mission should keep the whole house warmer; better eaves and new ridge vents will keep the loft properly ventilated….all of which could have been achieved with a nice new thatch I think; I’m not sure Daisy would agree…or her neighbours come to that!
A few of our clients have had problems with algal growth on their roofs of late. Algae will populate a surface in damp conditions, creating and living within a gel that holds moisture, thus maintaining an environment to suit itself. On a thatched roof the algae will coat the ends of the reed, almost gluing it together and creeping across an area until it is covered completely. After the unusually long dry summer we have just had, any algal mass will have dried to a crust and either split apart, forming rifts in the surface of the thatch, or falling away from the thatch and taking the weaker ends of the reeds with it.
When summers are consistently dry and winters cold and frosty, algal growth is much inhibited but with increasingly warmer winters and wetter summers, conditions for algae are about perfect.
At present, there aren’t any treatments that are effective. We can shear off the surface, which will make it less unsightly, but the algae will soon regrow so it is not a long lasting solution. Once the rain returns, any rifts formed will likely soon rehydrate, but keep an eye on them and ask your thatcher for advice if you have any concerns.
With a wheat reed re-thatch to start soon, I spoke to my supplier to see how the harvest has gone this year. It’s fairly good news as although the wheat grew a little shorter, the stems are thicker and therefore more durable. We will all have to adjust our technique to suit the reed, but that keeps us on our toes and gives the apprentice something new to learn.