Concrete

Once the main digging out was over, the next task was to install the drainage pipe to take the water from the kitchen sink to outside the building (through a hole in the wall below ground level) and eventually to the septic tank. This pipe was laid in a trench and then backfilled. Next, the damp proof membrane, a tough polythene sheet, laid over the entire floor and turned up at the edges to keep out the damp. Then, sheets of rigid extruded polystyrene insulation to keep out the cold.

To level the concrete floor I poured a strip of concrete on either side of the barn (exactly level with each other) on the first day, then once it had started to harden, I was able to pour the concrete in between these two slabs, using a straight edge to tamp the concrete between them and thus get an exactly level floor. Short bars of reinforcement left protruding from the first slabs were cast into the second slab, ensuring that the floor eventually acts as a single rigid floor.

To get my two perimeter slabs exactly at the same level, I first had to construct and level shuttering boards which held back the wet concrete. The foam insulation boards were too soft to fix the shutter boards to and I couldn't fix them to stakes driven into the ground as this would have punctured the damp proof membrane. I improvised by suspending the boards from spars (left over from the hedge laying) fixed to the floor beams above (alas no pictures of this).

On Thursday the 6 tonnes of aggregate and 700kg of cement were delivered to the house. Now I had to transport it to the barn. I shovelled the aggregate into the backbox on the tractor (about 200kg at a time) transported it down the path to the barn, then shovelled it out. 15 or so trips later I had moved about half the aggregate and could start with mixing the concrete and wheel-barrowing it into the barn, where once each shuttered area was filled I could tamp and smooth it.

the first half (3 tonnes) of the aggregate moved, ready to start mixing

The first pair of preimeter slabs, levelled and level with each other

It was 6.00pm on Thursday before this was complete. Thankfully John had volunteered to help me on Friday as the second days pour was perhaps 50% bigger Than Thursday's. Nonetheless, it still seemed a daunting task and as I had to leave for my flight home by 5.00pm on Friday afternoon, I decided to make an early start. 

At 6.00am I took down the shutters from the previous day's concrete and started the transportation of the remaining aggregate. John joined me at 8.00 and by 9.30 we had it all at the barn.  For the pour I loaded the mixer with aggregate, cement and water, and John wheel-barrowed the resulting concrete into the barn and performed the preliminary levelling. We tamped the floor together and by 2.30pm we were done. Over the two days with loading and unloading about 20 tonnes of aggregate and cement shovelled and about 8 tonnes of concrete barrowed and poured. We were tired!

The central slab being slowly filled

All done

Another hour and a half of cleaning up and a few areas of stone filling later and it was time to shower, eat, lock up and leave for the airport. A successful couple of weeks work!

New doorway complete (this will be internal eventually and plastered over, so no worries about concrete in lieu of stonework)

Ready for windows and doors next time

After Gabriele's comment on the last post, here's the barn back in 2007...

A metre of collapsed roof and rubble inside...

...saplings growing out of the walls.

After the initial ivy and bramble removal