Shelter building, be it small survival bivouac or palatial log cabin, always requires a sound plan before the work starts and that’s exactly where we were at on a chilly, wintery morning among the bare, hazel coppice and towering, skeletal oak trees. Resisting the urge to be too ambitious by embarking on a full Celtic roundhouse or Anglo Saxon long house we settled on a small, rectangular floor plan with the doorway at one end, just big enough for one hypothetical person to live in comfortably through the winter months. This would mean allowing enough room to fit a raised bed, make a fire place and still have enough room inside to work, cook and store kit in bad weather. The roof would be a simple double pitched affair continuing around the back of the house in an arc at roughly the same pitch (around 50 degrees). The initial planning brain storm also bought to light several problems that typically reduce the effectiveness and life expectancy of survival shelters. We were determined to provide our own answers to these problems but ultimately, only time will tell if our efforts have worked.
Our building plan had highlighted the need for the shelter to be kept fairly small and therefore easy to heat with a small open fire inside. Previous research had shown that similar ancient dwellings were often built without chimneys, instead allowing the central fire to form a ‘smoke ceiling’ above head height which would slowly permeate through the roof thatch. This helped preserve the roof timbers and kill off any resident bugs overhead. However, these structures were built to house an entire family and therefore, much larger with higher roofs. Our humble woodland bedsit would be more like a lung bursting smokehouse if we followed the same principle so we came up with the idea of a ‘dormer window’ style opening near the top of the roof on the opposing side to the prevailing wind. With our shelter design being so completely enclosed, this opening would also let in some light. The combined window and chimney idea became affectionately known as the ‘wimney’.
Usually, when using forest floor debris to thatch a shelter the huge volume of materials is gradually piled against the shelter from ground level upwards. In order to achieve our ventilation gap between roof and ground we would need to prevent the leaf mulch and jumbled medley of materials from just slipping right off the ends of the rafters and so the ‘giant thatch retaining sausage’ was born. A big, long bundle of twiggy brash wood, lashed to the end of each rafter about a foot up from the ground, forming a continuous buffer line running around the lowest point of the shelter roof and sweeping up and over the porch (yes, we built a porch too!). The thatching materials would sit against this buffer creating the desired depth of a foot but still leaving our all-important ventilation gap. Where required, horizontal hazel poles lay against the rafters to provide a sound base, followed by a good layer of spiky brash wood to close up any gaps and give a good ‘sticky’ surface (excuse the pun, but it is rather good…) for the leaf mulch layer to adhere to.
The giant thatch retaining sausage (GTRS for short) did a great job of keeping the first insulating layer of leaves exactly where we wanted them and before long our little hut in the woods began to blend in beautifully with it’s surroundings. Just down the track we were fortunate to have a huge swathe of tall, mature bracken. We made the most of this seasonal resource by taking just enough to give a good coverage to our roof, leaving the rest for the ticks. When harvesting bracken it’s important to cut the stems rather than pull at them. For starters, the roots aren’t usually that deep and if the plant is removed roots and all, there’ll be no bracken for the following year. Also, the stems have a sharp ridge that will give you the mother of all paper cuts as you tug them up. Instead, gather together a good bunch and using a long bladed knife, carefully slice through the stems with a sloping angle at ground level. The resulting long, pointed stems we found to be ideal for poking through the leaf mulch and the brash wood thatch layers before folding the bushier fronds over to lay against the roof. By starting at the bottom of the roof and working upwards towards the ridge, each course of fronds overlaid the previous for maximum rain shedding, with the added bonus of ‘pinning’ the mulch and brash layers together like a thatching spar.