Above are some lovely shots of our cockles recently poured into the void under a timber suspended floor on one of our current jobs on site.
The project is to extend, refurbish and repair an existing Victorian terrace building, which has suffered terribly under the hands of many previous owners who thought they were making ‘improvements’, or thought that cutting some corners wouldn’t hurt. Decades later, this once beautifully constructed brick and lime mortar building with suspended timber floors, had had all it’s brick work, inside and out, covered in cement or ‘waterproofing’ paint. Its timber floors stripped out and concrete poured in as an ‘economic’ replacement, and in this case with no damp proof membrane between it and the very high water table!
As you can imagine, soon timbers swelled, walls went mouldy, pipes corroded and plants started growing up through the floors…
We, along with our client and Stratos Construction Ltd have been working to put all that right, using traditional and sustainable techniques and materials. One of the measures to help balance the very high moisture levels on this site is the use of cockle shells in the floor void under the new re-instated suspended timber floor. The cockle shells absorb and release moisture levels dependent on their surrounding conditions. If it’s wet they soak it up and when it’s dry they let it go. “Just like lime!” I hear you cry, well, yes. It is lime in essence. If you burn shells in a kiln at the right temperature you get Calcium Carbonate, yep, you guessed it, Lime!
In Europe cockle shells are used quite widely for this purpose and they are also used as insulation in closed unventilated voids to soak up excess moisture and add to insulation levels. On our site we were unable to utilise the cockles warming properties due to having to vent the timber floor.
But, what a great use of a natural, non-toxic waste material!