For stability of the bio-digester and ease of maintaining the area of the digester I have started to cover the top of the dome with concrete. I am only applying a thin layer of concrete. In the design manual it was only recommended to have soil over the dome however I am finding that the area is growing lots of weeds. This is probably due to readily available moisture and lots of nutrients from spillage of the manure as I feed the digester. I need to be conscious of damaging the dome which may crack and then there will be loss of the methane gas. So only a 45 mm thick concrete cover will be applied.
I am pouring the concrete in two stages. This is because if I ever need to repair the plumbing that is buried in the earthen layer the I will only need to break open a small section of the concrete.
I am looking forward to completing this task as I use this area everyday and have been unable to use the area well due to getting soil on my tools as I sit them on the raised dome or getting manure on the raised dome creating a high nutrient problem.
Another project that is pending is to build a new woodshed to create more space for firewood. Now that we regularly use the rocket stove we will consume more firewood and the type of fuel for the rocket stove is different so more space to accommodate the different types of wood and also space to allow for dry time. So each time I have been doing some concreting I have been putting in the stirrups for the posts of the shed.
I have been re-purposing slasher blades that were destined to a scrap merchant. Should be able to stand up to the task.
©2016 Tom Kendall; diyfoodandhealth.com, incorporating Permaculture Research Institute Sunshine Coast, simplicity, permaculture, self reliance and homesteading, bio-digester , concreting.