We have a great resource in the pond, which we knew about from when we drained it in 2011, but we had not appreciated until this year its amazing building material potential: pale blue-grey boulder clay, which underlies much of Suffolk. Continue reading “Wonderful clay”
Looking around a typical Suffolk village, houses repaired with lime are still quite rare. It is clear that many homeowners and builders have yet to be persuaded of the vital importance of breathability and the use of traditional materials on an ancient structure. There is clearly a huge backlog of work to be done and, judging by the stories we hear from time to time about the terrible problems found in buildings that were repaired thoughtlessly in the 20th century, the damage is mounting right across East Anglia’s huge stock of historic houses.
There is a problem, however, when you start digging into the detail. Even among the experts in these old techniques, there is plenty of disagreement, and sometimes it gets quite heated. As experience grows again, after decades in which some skills were in danger of being lost, ideas are bound to evolve further.
So rather than try to pass on definitive advice, these posts have been setting out some of the techniques we used – or hired experts to use – and we also note where our own ideas and the advice from experts have changed over time, for example our decision to switch from the sand and lime render we used in the first year of the project to chalk and lime plaster for later phases.
More generally, it is important to read and discuss, to take advice from more than one source and to think through the jobs yourself with an open mind, focusing on the particular characteristics of the building concerned. The key points are:
always protect old material, and never do anything to it that isn’t reversible
in the case of infills and coatings, never put in anything that isn’t breathable.
and of course, put some effort into learning about the techniques you decide to use (or hire contractors to use for you).
The remaining pond mud, piled in the garden – perhaps 80 tons – was removed and used for landscaping adjustments, and grass was laid.
The well was properly capped with a steel cover, screwed down, on which limestone slabs were relaid.
A steel structure was built by the same people to make loft access safer.
A brick and stone patio was constructed outside the kitchen with a channel for the power supply and hose of an electric pump for topping up the pond. The flow rates were tested. At the worst of the 2011- 2012 drought, when the well was at the lowest level we have recorded, it produced more than 2 cubic metres of water a day which would be adequate to top up the pond in a summer drought. At other times its productivity was much higher.
The shallow trench round part of the house, which had been dug roughly to prevent damp earth lying against the brick footings above the inside floor level, was redone more carefully. A low brick retaining wall was built, the bottom of the trench the was lined with geotextile, and several inches of gravel placed on top. It stopped the damp coming through the lower bricks and discolouring the limewash on the inside of the brick footings.
Felix Oliver, our next door neighbour, replaced the old stairs with a new oak staircase to a similar pattern but much better finished. The design was negotiated with, and approved by, building control. The result has been widely admired. It fits perfectly at the top to a very uneven sloping floor. Felix is a professional wooden boatbuilder as well as a specialist in oak-framed buildings – see this link to Suffolk Timber Frame Buildings – and his boatbuilding skills show. He also installed 3 new oak studs to replace the rather agricultural – and recent – softwood posts that had been there before.
Insulation was put in the roof above the north bedroom, bathroom and landing, but only on the flat surfaces – the side sloping surfaces were too difficult to access. Part of the the loft area was then floored so it could be used for storage. We discovered that modern polystyrene insulation had been laid under the tiles of the roof when it was redone about 30 years ago and it seems to be intact. There is still a substantial airgap round the rafters, which is reassuring.
The south and east walls were limewashed, pending full re-rendering. All the external window surfaces were oiled with linseed. We couldn’t decide what colour to paint them and linseed oil seems a very good wood preservative and water repellent, so we may just keep coating them for a year or two.
The pond was cleared, removing hundreds of tons of mud, using it to landscape the garden and shrink the overall size of the pond back to where it probably was before the banks were broken down – see the blogroll link to the pond blog for all the details. This took from July to nearly the end of the year so very little was done on the house during this time.
The wall repaired in 2009 was limewashed the following spring with a colour made up to our specification by Ted Ingleby, the well known traditional paint manufacturer of Glemsford, Suffolk, which he called Rodgers Flint. We asked him to match the very attractive colour of the render itself, which came from the sand we used. (We took it to him painted onto a flint). The recipe is on his file and we have continued to order it.
There turned out to be a bit of controversy over grades of limewash – one for the those into the detail of repairing old buildings. Ted is very keen on an ancient Suffolk recipe using tallow, which he markets for outdoor use. It can cover a wall effectively in three coats rather than five and is very waterproof, and has considerably better coverage and durability than some other versions of limewash. But various books we consulted advised against tallow as not breathable enough, and suggested linseed oil was better, or even plain limewash in sheltered positions. Three of our walls are very sheltered.
We decided to add new coats the following year, 2011, using Ted Ingleby’s interior limewash, with linseed oil, on the outside. Continue reading “Limewash”
There was some damage to the inside panels of wattle and daub during the replacement of the sole plates. The building contractors re-rendered the bottom 30 – 50cm cm or so of the outside of the wall to weatherproof it over the narrow gap that appeared, using lime mortar. But on the inside there were a number of breaks and gaps in the clay where the old panel infill fell out when the building was lifted. Some thermalite blocks, which had been used in previous repairs, also fell out.
The empty panels were filled from the inside with clay daub. After letting the work dry and crack for six weeks we put on a clay plaster made from daub mixed 2:1 with lime mortar and finally a thin coat of haired lime plaster bought ready-mixed from Anglia Lime. This was also used to plaster the thermalite blocks which had been used to fill in the old kitchen doorway, and was very effective in strengthening a section of old crumbling plaster in the kitchen. Continue reading “Wattle and daub – inside repairs”
Chris and I filled the very large number of holes left in the kitchen and living room by the replacement of the sole plates, including some complete damaged panels. Wherever possible, we used hazel lattices and clay daub for the repairs, with a skim of lime render inside, finished with limewash. We salvaged old clay and plaster. See ‘wattle and daub’ and ‘wattle and daub inside’ posts.
The interior ground floor woodwork was painted and the brickwork limewashed.
An electric storage heater Aga was installed in the kitchen.
We deliberately spurned a fitted kitchem. The idea is that separate pieces of kitchen furniture unattached to the walls allow the walls to breathe and stay dry – important given our repair philosophy of using the natural characteristics of the materials to keep the building dry through encouraging breathability.
We paid two local landscapers to lay hardcore and a stepping stone path from the entrance to the front door, and to make a small brick patio outside the front door, linked to the doorstep by limestone slabs on a brick plinth. They also made a low brick wall to hold back the slightly higher level area outside the kitchen window, which we gravelled. They erected a garden shed we had bought.
A fencing contractor installed a full size five bar farm gate. We later replanted the damaged hedge either side of the gate with hawthorn and field maple.
The east wall was repaired with clay, but in patches where there were holes, and on the north wall there were also areas that needed repair.
We planted a beech hedge on the north boundary of the kitchen garden.
A Morso wood burning stove was installed by us in the sitting room. It has a rated output of 10Kw maximum, though we were toild to take all these measurements with a pinch of salt. It does however create a lot of heat that spreads throughout the building after a few days, as the massive chimney brickwork warms.
We learnt the basics of wattle and daub on an Essex County Council course at Onchors Farm near Braintree. The course tutors were Lydia Bucknell and Peter Roe of Traditionally Plastered. This was a prelude to a long term programme of repairs to the daub, inside and outside.
The first thing to think about is a supply of clay daub. On the course, we learnt to make it ourselves. The basic ingredient in that part of Essex was a pale yellow clay, containing small chalk pebbles, from a pit on the farm, which was quite similar in texture to the material in the walls of our cottage.
At Onchors farm, the clay was mixed with sand, chopped straw and cow manure and then trodden (literally) until the texture changed to plastic and doughy, not unlike plasticine. It took 3 people 30-40 minutes to tread one large wheelbarrow load into the right condition. Traditional builders used to short circuit this laborious process by leaving cows tethered in the clay pits to tread the mixture. Modern machinery can be used to make daub in quantity, but do not use cement mixers, because the material is too glutinous. Onchors farm has a machine very like a large bread doughmaker, with rotating arms. Given our experience of DIY daub making, we decided to buy ready made daub from the farm in tubs. Continue reading “Wattle and daub”
The floor was also of special interest to the archaeologists who investigated the building, which was a condition of planning permission. Once the concrete had been removed, they meticulously worked down through the old floor layers using trowels and logging every piece of broken pottery and other material they found. They were on site for nearly a week, so there was constant tension with the builders, whose timetable was at risk because of need to investigate each layer under the floor. The archaeologists tried hard to be helpful, and did shift quite a lot of spoil for the builders. The main find was the base of the old brewing hearth (see ‘A house unlived in for centuries’). Bricks were taken away for dating. We are still waiting for the results.
Because the floor was due to be replaced and lowered 8 inches, it was imperative to deepen and strengthen the footings, which were mostly only two or three bricks deep. They were built down a metre by digging a trench in sections around the house. New bricks were laid almost direct onto the clay, on a thin layer of limecrete.
The ground floor – removing cement and replacing it with limecrete
The cement floor was the biggest single problem. It had to be removed to make the building habitable, because headroom on the ground floor was well under 6 feet. The plan was to drop the floor 8 inches. The architects advised, and indeed the conservation officer insisted, on a limecrete floor, using expanded glass balls from power station waste as a lightweight filler instead of gravel. Underneath was a thick layer of a similar expanded glass, for insulation, and also to allow water to drain away quickly from beneath the building. The winter water table, as measured by the well outside, is less than half a metre below the floor.
We gained planning permission and listed building consent for structural repairs to the building, installation of services, a new vehicle entrance and construction of a cart-lodge style garage and also a small extension – essentially, a porch, though with a shower room squeezed in. We decided we would split this into several phases, leaving the porch extension, some of the repair work and the garage until later.