by David Cameron
There was an article in the Chronicle Herald a few days ago referencing the redundant book/journal situation in NS universities.
The universities have decided to have one facility in the province for storage and dump the rest.
Dumping will mean books going to the landfills if no one finds alternate uses for the bound journals, and we are talking hundreds of thousands of books! We recently sourced several thousand of these redundant bound journals from Dalhousie University through its Sustainability Office.
Books are made of cellulose. Some commercial insulation products are made from cellulose. Bound journal cellulose is very dense with a high clay content. So it probably isn’t as good for insulation as shredded paper cellulose from newspaper or regular books.
But the bound journals are free! And they don’t require a studded cavity to hold the material in place. We know straw bales make great insulated walls, especially when covered with clay/sand plaster. Maybe we could build bookwalls and coat them with earth plaster? If we did this to retrofit the existing old school walls, the rooms would be easier to heat. We don’t have roof overhangs to protect earthplaster walls on the exterior, so we should try it from the inside, against existing walls. Books are only about a foot long so the bookwalls will take up 1/2 the interior space of straw bale walls used in the same fashion.
Let’s put up a straw bale wall also, to have something known and warm to compare with. And let’s build the bookwall leaving some of the original school wall exposed so we can make direct temperature-transfer comparisons.
We built the 22 x 6.5 foot bookwall using 1500+ books sitting on a vapour-barrier and 2 inches of recycled foundation-type foam insulation on the room’s concrete slab floor. We opened the books so we could inter-weave the books for greater stability and more insulating voids. The shear weight of the wall made it rock- solid…gravity works! We screwed the covers of the very top layer to the existing wall at the studs to increase stability.
Then the bookwall, which now looked like some exotic sedimentary wall of colorfully striped white rock, was hand-brushed with a slurry made from Lunenburg County drumlin clay (sourced at Maughan’s Construction), to help the next layer of clay/sand/chopped straw “take” to the bookwall surface. And it did, very nicely.
Many hands made short work of it. So short that we forgot to leave a “truth- window” section uncovered!
Master Plasterer, Keith Dietrich, showed the student earth-plasterers how to get really good, sticky earthplaster mixes using all local materials.
We put the recycled “truth-window” in place and applied the thicker layer of clay/sand/ chopped straw (mixed in an electric cement-type mixer) to the wall by hand. The work went very quickly.
The bookwall is so stable and solid we were able to use steel trowels to push the earthplaster hard against the bookwall surface, getting quite a flat finish as a result.
The earthplaster was allowed to dry with a dehumidifier in the room to help remove the moisture.
In spring of 2013 the wall will get a finish coat of plaster.
Earthplasters are great materials, with less embodied energy than portland cements or gyprock. They have a wide range of surface finish, texture and even
Earthplasters add thermal mass to a room, absorbing and releasing heat, and also can modify/temper room humidity by absorbing air moisture during high-humidity times and releasing it during drier periods. Earthplasters may be readily sourced in most areas of Nova Scotia.
Does the bookwall increase the R value of the original wall? In other words, does the bookwall + original wall have a greater resistance to heat transfer than the original gyprocked studwall alone?
A simple test of this is made by putting ones hand on the original wall and then on the bookwall on a cold day when there is no incoming solar heat from windows. The original wall feels very cold to the touch – heat is leaving one’s hand very quickly. When touching the bookwall, it feels warmer. In fact the surface of both walls are exactly the same temperature, but the greater insulation value of the bookwall means heat leaves ones hand more slowly, so the wall feels warmer than the original wall. It works! An educated guess puts the original wall at R12 and the combined original and bookwall at R24…to be verified.
Further testing of R value and moisture stability will be made of the walls as resources and time allow. We also hope to carry out more bookwall building and testing in the spring of 2013. Please let us know if you would like to learn the skills involved in earthplastering.
Also in 2013 The Blockhouse School project is planning to hold an “Altered Book” installation event. Artists and experimenters will be asked to submit and carry out proposals for using books in unusual ways. The event will be curated by Karen Langlois.
We’d like to thank Keith Dietrich for the earthplaster instruction, the students for their hands-on efforts and Lauren Levine for feeding us all so well.